1 News for the tz database
3 Release 2024a - 2024-02-01 09:28:56 -0800
6 Kazakhstan unifies on UTC+5 beginning 2024-03-01.
7 Palestine springs forward a week later after Ramadan.
8 zic no longer pretends to support indefinite-past DST.
9 localtime no longer mishandles Ciudad Juárez in 2422.
11 Changes to future timestamps
13 Kazakhstan unifies on UTC+5. This affects Asia/Almaty and
14 Asia/Qostanay which together represent the eastern portion of the
15 country that will transition from UTC+6 on 2024-03-01 at 00:00 to
16 join the western portion. (Thanks to Zhanbolat Raimbekov.)
18 Palestine springs forward a week later than previously predicted
19 in 2024 and 2025. (Thanks to Heba Hamad.) Change spring-forward
20 predictions to the second Saturday after Ramadan, not the first;
21 this also affects other predictions starting in 2039.
23 Changes to past timestamps
25 Asia/Ho_Chi_Minh's 1955-07-01 transition occurred at 01:00
26 not 00:00. (Thanks to Đoàn Trần Công Danh.)
28 From 1947 through 1949, Toronto's transitions occurred at 02:00
29 not 00:00. (Thanks to Chris Walton.)
31 In 1911 Miquelon adopted standard time on June 15, not May 15.
35 The FROM and TO columns of Rule lines can no longer be "minimum"
36 or an abbreviation of "minimum", because TZif files do not support
37 DST rules that extend into the indefinite past - although these
38 rules were supported when TZif files had only 32-bit data, this
39 stopped working when 64-bit TZif files were introduced in 1995.
40 This should not be a problem for realistic data, since DST was
41 first used in the 20th century. As a transition aid, FROM columns
42 like "minimum" are now diagnosed and then treated as if they were
43 the year 1900; this should suffice for TZif files on old systems
44 with only 32-bit time_t, and it is more compatible with bugs in
45 2023c-and-earlier localtime.c. (Problem reported by Yoshito
48 localtime and related functions no longer mishandle some
49 timestamps that occur about 400 years after a switch to a time
50 zone with a DST schedule. In 2023d data this problem was visible
51 for some timestamps in November 2422, November 2822, etc. in
52 America/Ciudad_Juarez. (Problem reported by Gilmore Davidson.)
54 strftime %s now uses tm_gmtoff if available. (Problem and draft
55 patch reported by Dag-Erling Smørgrav.)
57 Changes to build procedure
59 The leap-seconds.list file is now copied from the IERS instead of
60 from its downstream counterpart at NIST, as the IERS version is
61 now in the public domain too and tends to be more up-to-date.
62 (Thanks to Martin Burnicki for liaisoning with the IERS.)
64 Changes to documentation
66 The strftime man page documents which struct tm members affect
67 which conversion specs, and that tzset is called. (Problems
68 reported by Robert Elz and Steve Summit.)
71 Release 2023d - 2023-12-21 20:02:24 -0800
74 Ittoqqortoormiit, Greenland changes time zones on 2024-03-31.
75 Vostok, Antarctica changed time zones on 2023-12-18.
76 Casey, Antarctica changed time zones five times since 2020.
77 Code and data fixes for Palestine timestamps starting in 2072.
78 A new data file zonenow.tab for timestamps starting now.
80 Changes to future timestamps
82 Ittoqqortoormiit, Greenland (America/Scoresbysund) joins most of
83 the rest of Greenland's timekeeping practice on 2024-03-31, by
84 changing its time zone from -01/+00 to -02/-01 at the same moment
85 as the spring-forward transition. Its clocks will therefore not
86 spring forward as previously scheduled. The time zone change
87 reverts to its common practice before 1981.
89 Fix predictions for DST transitions in Palestine in 2072-2075,
90 correcting a typo introduced in 2023a.
92 Changes to past and future timestamps
94 Vostok, Antarctica changed to +05 on 2023-12-18. It had been at
95 +07 (not +06) for years. (Thanks to Zakhary V. Akulov.)
97 Change data for Casey, Antarctica to agree with timeanddate.com,
98 by adding five time zone changes since 2020. Casey is now at +08
101 Changes to past tm_isdst flags
103 Much of Greenland, represented by America/Nuuk, changed its
104 standard time from -03 to -02 on 2023-03-25, not on 2023-10-28.
105 This does not affect UTC offsets, only the tm_isdst flag.
106 (Thanks to Thomas M. Steenholdt.)
110 A new data file zonenow.tab helps configure applications that use
111 timestamps dated from now on. This simplifies configuration,
112 since users choose from a smaller Zone set. The file's format is
113 experimental and subject to change.
117 localtime.c no longer mishandles TZif files that contain a single
118 transition into a DST regime. Previously, it incorrectly assumed
119 DST was in effect before the transition too. (Thanks to Alois
120 Treindl for debugging help.)
122 localtime.c's timeoff no longer collides with OpenBSD 7.4.
124 The C code now uses _Generic only if __STDC_VERSION__ says the
125 compiler is C11 or later.
127 tzselect now optionally reads zonenow.tab, to simplify when
128 configuring only for timestamps dated from now on.
130 tzselect no longer creates temporary files.
132 tzselect no longer mishandles the following:
134 Spaces and most other special characters in BUGEMAIL, PACKAGE,
137 TZ strings when using mawk 1.4.3, which mishandles regular
138 expressions of the form /X{2,}/.
140 ISO 6709 coordinates when using an awk that lacks the GNU
141 extension of newlines in -v option-arguments.
143 Non UTF-8 locales when using an iconv command that lacks the GNU
144 //TRANSLIT extension.
146 zic no longer mishandles data for Palestine after the year 2075.
147 Previously, it incorrectly omitted post-2075 transitions that are
148 predicted for just before and just after Ramadan. (Thanks to Ken
149 Murchison for debugging help.)
151 zic now works again on Linux 2.6.16 and 2.6.17 (2006).
152 (Problem reported by Rune Torgersen.)
154 Changes to build procedure
156 The Makefile is now more compatible with POSIX:
157 * It no longer defines AR, CC, CFLAGS, LDFLAGS, and SHELL.
158 * It no longer uses its own 'cc' in place of CC.
159 * It now uses ARFLAGS, with default specified by POSIX.
160 * It does not use LFLAGS incompatibly with POSIX.
161 * It uses the special .POSIX target.
162 * It quotes special characters more carefully.
163 * It no longer mishandles builds in an ISO 8859 locale.
164 Due to the CC changes, TZDIR is now #defined in a file tzfile.h
165 built by 'make', not in a $(CC) -D option. Also, TZDEFAULT is
166 now treated like TZDIR as they have similar roles.
168 Changes to commentary
170 Limitations and hazards of the optional support for obsolescent
171 C89 platforms are documented better, along with a tentative
172 schedule for removing this support.
175 Release 2023c - 2023-03-28 12:42:14 -0700
177 Changes to past and future timestamps
179 Model Lebanon's DST chaos by reverting data to tzdb 2023a.
180 (Thanks to Rany Hany for the heads-up.)
183 Release 2023b - 2023-03-23 19:50:38 -0700
185 Changes to future timestamps
187 This year Lebanon springs forward April 20/21 not March 25/26.
188 (Thanks to Saadallah Itani.) [This was reverted in 2023c.]
191 Release 2023a - 2023-03-22 12:39:33 -0700
194 Egypt now uses DST again, from April through October.
195 This year Morocco springs forward April 23, not April 30.
196 Palestine delays the start of DST this year.
197 Much of Greenland still uses DST from 2024 on.
198 America/Yellowknife now links to America/Edmonton.
199 tzselect can now use current time to help infer timezone.
200 The code now defaults to C99 or later.
201 Fix use of C23 attributes.
203 Changes to future timestamps
205 Starting in 2023, Egypt will observe DST from April's last Friday
206 through October's last Thursday. (Thanks to Ahmad ElDardiry.)
207 Assume the transition times are 00:00 and 24:00, respectively.
209 In 2023 Morocco's spring-forward transition after Ramadan
210 will occur April 23, not April 30. (Thanks to Milamber.)
211 Adjust predictions for future years accordingly. This affects
212 predictions for 2023, 2031, 2038, and later years.
214 This year Palestine will delay its spring forward from
215 March 25 to April 29 due to Ramadan. (Thanks to Heba Hamad.)
216 Make guesses for future Ramadans too.
218 Much of Greenland, represented by America/Nuuk, will continue to
219 observe DST using European Union rules. When combined with
220 Greenland's decision not to change the clocks in fall 2023,
221 America/Nuuk therefore changes from -03/-02 to -02/-01 effective
222 2023-10-29 at 01:00 UTC. (Thanks to Thomas M. Steenholdt.)
223 This change from 2022g doesn't affect timestamps until 2024-03-30,
224 and doesn't affect tm_isdst until 2023-03-25.
226 Changes to past timestamps
228 America/Yellowknife has changed from a Zone to a backward
229 compatibility Link, as it no longer differs from America/Edmonton
230 since 1970. (Thanks to Almaz Mingaleev.) This affects some
231 pre-1948 timestamps. The old data are now in 'backzone'.
233 Changes to past time zone abbreviations
235 When observing Moscow time, Europe/Kirov and Europe/Volgograd now
236 use the abbreviations MSK/MSD instead of numeric abbreviations,
237 for consistency with other timezones observing Moscow time.
241 You can now tell tzselect local time, to simplify later choices.
242 Select the 'time' option in its first prompt.
244 You can now compile with -DTZNAME_MAXIMUM=N to limit time zone
245 abbreviations to N bytes (default 255). The reference runtime
246 library now rejects POSIX-style TZ strings that contain longer
247 abbreviations, treating them as UTC. Previously the limit was
248 platform dependent and abbreviations were silently truncated to
249 16 bytes even when the limit was greater than 16.
251 The code by default is now designed for C99 or later. To build on
252 a mostly-C89 platform, compile with -DPORT_TO_C89; this should
253 work on C89 platforms that also support C99 'long long' and
254 perhaps a few other extensions to C89. To support C89 callers of
255 tzcode's library, compile with -DSUPPORT_C89; however, this could
256 trigger latent bugs in C99-or-later callers. The two new macros
257 are transitional aids planned to be removed in a future version
258 (say, in 2029), when C99 or later will be required.
260 The code now builds again on pre-C99 platforms, if you compile
261 with -DPORT_TO_C89. This fixes a bug introduced in 2022f.
263 On C23-compatible platforms tzcode no longer uses syntax like
264 'static [[noreturn]] void usage(void);'. Instead, it uses
265 '[[noreturn]] static void usage(void);' as strict C23 requires.
266 (Problem reported by Houge Langley.)
268 The code's functions now constrain their arguments with the C
269 'restrict' keyword consistently with their documentation.
270 This may allow future optimizations.
272 zdump again builds standalone with ckdadd and without setenv,
273 fixing a bug introduced in 2022g. (Problem reported by panic.)
275 leapseconds.awk can now process a leap seconds file that never
276 expires; this might be useful if leap seconds are discontinued.
278 Changes to commentary
280 tz-link.html has a new section "Coordinating with governments and
281 distributors". (Thanks to Neil Fuller for some of the text.)
283 To improve tzselect diagnostics, zone1970.tab's comments column is
284 now limited to countries that have multiple timezones.
286 Note that leap seconds are planned to be discontinued by 2035.
289 Release 2022g - 2022-11-29 08:58:31 -0800
292 The northern edge of Chihuahua changes to US timekeeping.
293 Much of Greenland stops changing clocks after March 2023.
294 Fix some pre-1996 timestamps in northern Canada.
295 C89 is now deprecated; please use C99 or later.
296 Portability fixes for AIX, libintl, MS-Windows, musl, z/OS
297 In C code, use more C23 features if available.
298 C23 timegm now supported by default
299 Fixes for unlikely integer overflows
301 Changes to future timestamps
303 In the Mexican state of Chihuahua, the border strip near the US
304 will change to agree with nearby US locations on 2022-11-30.
305 The strip's western part, represented by Ciudad Juárez, switches
306 from -06 all year to -07/-06 with US DST rules, like El Paso, TX.
307 The eastern part, represented by Ojinaga, will observe US DST next
308 year, like Presidio, TX. (Thanks to Heitor David Pinto.)
309 A new Zone America/Ciudad_Juarez splits from America/Ojinaga.
311 Much of Greenland, represented by America/Nuuk, stops observing
312 winter time after March 2023, so its daylight saving time becomes
313 standard time. (Thanks to Jonas Nyrup and Jürgen Appel.)
315 Changes to past timestamps
317 Changes for pre-1996 northern Canada (thanks to Chris Walton):
319 Merge America/Iqaluit and America/Pangnirtung into the former,
320 with a backward compatibility link for the latter name.
321 There is no good evidence the two locations differ since 1970.
322 This change affects pre-1996 America/Pangnirtung timestamps.
324 Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and
325 Yellowknife did not observe DST in 1965, and did observe DST
326 from 1972 through 1979.
328 Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28.
330 Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00.
331 (Thanks to Alois Treindl.)
333 Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time),
334 not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.)
338 Although tzcode still works with C89, bugs found in recent routine
339 maintenance indicate that bitrot has set in and that in practice
340 C89 is no longer used to build tzcode. As it is a maintenance
341 burden, support for C89 is planned to be removed soon. Instead,
342 please use compilers compatible with C99, C11, C17, or C23.
344 timegm, which tzcode implemented in 1989, will finally be
345 standardized 34 years later as part of C23, so timegm is now
346 supported even if STD_INSPIRED is not defined.
348 Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone.
349 (Problem reported by Đoàn Trần Công Danh.)
351 Fix bug in zic on hosts where malloc(0) yields NULL on success.
352 (Problem reported by Tim McBrayer for AIX 6.1.)
354 Fix zic configuration to avoid linkage failures on some platforms.
355 (Problems reported by Gilmore Davidson and Igor Ivanov.)
357 Work around MS-Windows nmake incompatibility with POSIX.
358 (Problem reported by Manuela Friedrich.)
360 Port mktime and strftime to debugging platforms where accessing
361 uninitialized data has undefined behavior (strftime problem
362 reported by Robert Elz).
364 Check more carefully for unlikely integer overflows, preferring
365 C23 <stdckdint.h> to overflow checking by hand, as the latter has
368 Changes to build procedure
370 New Makefile rule check_mild that skips checking whether Link
371 lines are in the file 'backward'. (Inspired by a suggestion from
375 Release 2022f - 2022-10-28 18:04:57 -0700
378 Mexico will no longer observe DST except near the US border.
379 Chihuahua moves to year-round -06 on 2022-10-30.
380 Fiji no longer observes DST.
381 Move links to 'backward'.
382 In vanguard form, GMT is now a Zone and Etc/GMT a link.
383 zic now supports links to links, and vanguard form uses this.
384 Simplify four Ontario zones.
385 Fix a Y2438 bug when reading TZif data.
386 Enable 64-bit time_t on 32-bit glibc platforms.
387 Omit large-file support when no longer needed.
388 In C code, use some C23 features if available.
389 Remove no-longer-needed workaround for Qt bug 53071.
391 Changes to future timestamps
393 Mexico will no longer observe DST after 2022, except for areas
394 near the US border that continue to observe US DST rules.
395 On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
396 from -07 (-06 with DST) to year-round -06, thus not changing
397 its clocks that day. The new law states that Chihuahua
398 near the US border no longer observes US DST.
399 (Thanks to gera for the heads-up about Chihuahua.)
401 Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.)
402 For now, assume DST is suspended indefinitely.
406 Move links to 'backward' to ease and simplify link maintenance.
407 This affects generated data only if you use 'make BACKWARD='.
409 GMT is now a Zone and Etc/GMT a link instead of vice versa,
410 as GMT is needed for leap second support whereas Etc/GMT is not.
411 However, this change exposes a bug in TZUpdater 2.3.2 so it is
412 present only in vanguard form for now.
414 Vanguard form now uses links to links, as zic now supports this.
416 Changes to past timestamps
418 Simplify four Ontario zones, as most of the post-1970 differences
419 seem to have been imaginary. (Problem reported by Chris Walton.)
420 Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay
421 to 'backzone'; backward-compatibility links still work, albeit
422 with some different timestamps before November 2005.
426 zic now supports links to links regardless of input line order.
427 For example, if Australia/Sydney is a Zone, the lines
428 Link Australia/Canberra Australia/ACT
429 Link Australia/Sydney Australia/Canberra
430 now work correctly, even though the shell commands
431 ln Australia/Canberra Australia/ACT
432 ln Australia/Sydney Australia/Canberra
433 would fail because the first command attempts to use a link
434 Australia/Canberra that does not exist until after the second
435 command is executed. Previously, zic had unspecified behavior if
436 a Link line's target was another link, and zic often misbehaved if
437 a Link line's target was a later Link line.
439 Fix line number in zic's diagnostic for a link to a link.
441 Fix a bug that caused localtime to mishandle timestamps starting
442 in the year 2438 when reading data generated by 'zic -b fat' when
443 distant-future DST transitions occur at times given in standard
444 time or in UT, not the usual case of local time. This occurs when
445 the corresponding .zi Rule lines specify DST transitions with TO
446 columns of 'max' and AT columns that end in 's' or 'u'. The
447 number 2438 comes from the 32-bit limit in the year 2038, plus the
448 400-year Gregorian cycle. (Problem reported by Bradley White.)
450 On glibc 2.34 and later, which optionally supports 64-bit time_t
451 on platforms like x86 where time_t was traditionally 32 bits,
452 default time_t to 64 instead of 32 bits. This lets functions like
453 localtime support timestamps after the year 2038, and fixes
454 year-2038 problems in zic when accessing files dated after 2038.
455 To continue to limit time_t to 32 bits on these platforms, use
456 "make CFLAGS='-D_TIME_BITS=32'".
458 In C code, do not enable large-file support on platforms like AIX
459 and macOS that no longer need it now that tzcode does not use
460 off_t or related functions like 'stat'. Large-file support is
461 still enabled by default on GNU/Linux, as it is needed for 64-bit
464 In C code, prefer C23 keywords to pre-C23 macros for alignof,
465 bool, false, and true. Also, use the following C23 features if
466 available: __has_include, unreachable.
468 zic no longer works around Qt bug 53071, as the relevant Qt
469 releases have been out of support since 2019. This change affects
470 only fat TZif files, as thin files never had the workaround.
472 zdump no longer modifies the environ vector when compiled on
473 platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
474 This avoid undefined behavior on POSIX platforms.
477 Release 2022e - 2022-10-11 11:13:02 -0700
480 Jordan and Syria switch from +02/+03 with DST to year-round +03.
482 Changes to future timestamps
484 Jordan and Syria are abandoning the DST regime and are changing to
485 permanent +03, so they will not fall back from +03 to +02 on
486 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.)
488 Changes to past timestamps
490 On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00.
492 Changes to past time zone abbreviations and DST flags
494 The temporary advancement of clocks in central Mexico in summer
495 1931 is now treated as daylight saving time, instead of as two
496 changes to standard time.
499 Release 2022d - 2022-09-23 12:02:57 -0700
502 Palestine transitions are now Saturdays at 02:00.
503 Simplify three Ukraine zones into one.
505 Changes to future timestamps
507 Palestine now springs forward and falls back at 02:00 on the
508 first Saturday on or after March 24 and October 24, respectively.
509 This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00.
510 (Thanks to Heba Hamad.)
512 Changes to past timestamps
514 Simplify three Ukraine zones to one, since the post-1970
515 differences seem to have been imaginary. Move Europe/Uzhgorod and
516 Europe/Zaporozhye to 'backzone'; backward-compatibility links
517 still work, albeit with different timestamps before October 1991.
520 Release 2022c - 2022-08-15 17:47:18 -0700
523 Work around awk bug in FreeBSD, macOS, etc.
524 Improve tzselect on intercontinental Zones.
528 Work around a bug in onetrueawk that broke commands like
529 'make traditional_tarballs' on FreeBSD, macOS, etc.
530 (Problem reported by Deborah Goldsmith.)
532 Add code to tzselect that uses experimental structured comments in
533 zone1970.tab to clarify whether Zones like Africa/Abidjan and
534 Europe/Istanbul cross continent or ocean boundaries.
535 (Inspired by a problem reported by Peter Krefting.)
537 Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
538 directory /a/b already exists.
540 Remove zoneinfo2tdf.pl, as it was unused and triggered false
541 malware alarms on some email servers.
544 Release 2022b - 2022-08-10 15:38:32 -0700
547 Chile's DST is delayed by a week in September 2022.
548 Iran no longer observes DST after 2022.
549 Rename Europe/Kiev to Europe/Kyiv.
551 Vanguard form now uses %z.
552 Finish moving duplicate-since-1970 zones to 'backzone'.
553 New build option PACKRATLIST
554 New tailored_tarballs target, replacing rearguard_tarballs
556 Changes to future timestamps
558 Chile's 2022 DST start is delayed from September 4 to September 11.
559 (Thanks to Juan Correa.)
561 Iran plans to stop observing DST permanently, after it falls back
562 on 2022-09-21. (Thanks to Ali Mirjamali.)
564 Changes to past timestamps
566 Finish moving to 'backzone' the location-based zones whose
567 timestamps since 1970 are duplicates; adjust links accordingly.
568 This change ordinarily affects only pre-1970 timestamps, and with
569 the new PACKRATLIST option it does not affect any timestamps.
570 In this round the affected zones are Antarctica/Vostok,
571 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
572 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
573 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
574 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
575 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
576 Pacific/Wake and Pacific/Wallis, and the affected links are
577 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
578 Pacific/Truk, and Pacific/Yap.
580 From fall 1994 through fall 1995, Shanks wrote that Crimea's
581 DST transitions were at 02:00 standard time, not at 00:00.
582 (Thanks to Michael Deckers.)
584 Iran adopted standard time in 1935, not 1946. In 1977 it observed
585 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
586 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
587 transition was on 05-27, not 03-21.
588 (Thanks to Roozbeh Pournader and Francis Santoni.)
590 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
591 considered DST, not standard time. Santiago and environs had moved
592 their clocks back to rejoin the rest of mainland Chile; put this
593 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
595 Some old, small clock transitions have been removed, as people at
596 the time did not change their clocks. This affects Asia/Hong_Kong
597 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
601 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
602 English now. Spelling of other names in Ukraine has not yet
603 demonstrably changed in common English practice so for now these
604 names retain old spellings, as in other countries (e.g.,
605 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
609 zic has a new option '-R @N' to output explicit transitions < N.
610 (Need suggested by Almaz Mingaleev.)
612 'zic -r @N' no longer outputs bad data when N < first transition.
613 (Problem introduced in 2021d and reported by Peter Krefting.)
615 zic now checks its input for NUL bytes and unterminated lines, and
616 now supports input line lengths up to 2048 (not 512) bytes.
618 gmtime and related code now use the abbreviation "UTC" not "GMT".
619 POSIX is being revised to require this.
621 When tzset and related functions set vestigial static variables
622 like tzname, they now prefer specified timestamps to unspecified ones.
623 (Problem reported by Almaz Mingaleev.)
625 zic no longer complains "can't determine time zone abbreviation to
626 use just after until time" when a transition to a new standard
627 time occurs simultaneously with the first DST fallback transition.
629 Changes to build procedure
631 Source data in vanguard form now uses the %z notation, introduced
632 in release 2015f. For example, for America/Sao_Paulo vanguard
633 form contains the zone continuation line "-3:00 Brazil %z", which
634 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
635 used in main and rearguard forms. The plan is for the main form
636 to use %z eventually; in the meantime maintainers of zi parsers
637 are encouraged to test the parsers on vanguard.zi.
639 The Makefile has a new PACKRATLIST option to select a subset of
640 'backzone'. For example, 'make PACKRATDATA=backzone
641 PACKRATLIST=zone.tab' now generates TZif files identical to those
642 of the global-tz project.
644 The Makefile has a new tailored_tarballs target for generating
645 special-purpose tarballs. It generalizes and replaces the
646 rearguard_tarballs target and related targets and macros, which
649 'make install' now defaults LOCALTIME to Factory not GMT,
650 which means the default abbreviation is now "-00" not "GMT".
652 Remove the posix_packrat target, marked obsolescent in 2016a.
655 Release 2022a - 2022-03-15 23:02:01 -0700
658 Palestine will spring forward on 2022-03-27, not -03-26.
659 zdump -v now outputs better failure indications.
660 Bug fixes for code that reads corrupted TZif data.
662 Changes to future timestamps
664 Palestine will spring forward on 2022-03-27, not 2022-03-26.
665 (Thanks to Heba Hamad.) Predict future transitions for first
666 Sunday >= March 25. Additionally, predict fallbacks to be the first
667 Friday on or after October 23, not October's last Friday, to be more
668 consistent with recent practice. The first differing fallback
669 prediction is on 2025-10-24, not 2025-10-31.
671 Changes to past timestamps
673 From 1992 through spring 1996, Ukraine's DST transitions were at
674 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
676 Chile's Santiago Mean Time and its LMT precursor have been adjusted
677 eastward by 1 second to align with past and present law.
679 Changes to commentary
681 Add several references for Chile's 1946/1947 transitions, some of
682 which only affected portions of the country.
686 Fix bug when mktime gets confused by truncated TZif files with
687 unspecified local time. (Problem reported by Almaz Mingaleev.)
689 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
690 (Problem reported by Christos Zoulas.)
692 When reading a version 2 or later TZif file, the TZif reader now
693 validates the version 1 header and data block only enough to skip
694 over them, as recommended by RFC 8536 section 4. Also, the TZif
695 reader no longer mistakenly attempts to parse a version 1 TZIf
696 file header as a TZ string.
698 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
699 when local time and UT cannot be determined for a timestamp.
701 Changes to build procedure
703 Distribution tarballs now use standard POSIX.1-1988 ustar format
704 instead of GNU format. Although the formats are almost identical
705 for these tarballs, ustar headers' magic fields contain "ustar"
706 instead of "ustar ", and their version fields contain "00" instead
707 of " ". The two formats are planned to diverge more significantly
708 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
709 format becomes obsolete and the tarballs switch to pax format, an
710 extension of ustar. For details about these formats, please see
711 "pax - portable archive interchange", IEEE Std 1003.1-2017,
712 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
715 Release 2021e - 2021-10-21 18:41:00 -0700
717 Changes to future timestamps
719 Palestine will fall back 10-29 (not 10-30) at 01:00.
720 (Thanks to P Chan and Heba Hemad.)
723 Release 2021d - 2021-10-15 13:48:18 -0700
726 Fiji suspends DST for the 2021/2022 season.
727 'zic -r' marks unspecified timestamps with "-00".
729 Changes to future timestamps
731 Fiji will suspend observance of DST for the 2021/2022 season.
732 Assume for now that it will return next year. (Thanks to Jashneel
737 'zic -r' now uses "-00" time zone abbreviations for intervals
738 with UT offsets that are unspecified due to -r truncation.
739 This implements a change in draft Internet RFC 8536bis.
742 Release 2021c - 2021-10-01 14:21:49 -0700
745 Revert most 2021b changes to 'backward'.
746 Fix 'zic -b fat' bug in pre-1970 32-bit data.
747 Fix two Link line typos.
748 Distribute SECURITY file.
750 This release is intended as a bugfix release, to fix compatibility
751 problems and typos reported since 2021b was released.
753 Changes to Link directives
755 Revert almost all of 2021b's changes to the 'backward' file,
756 by moving Link directives back to where they were in 2021a.
757 Although 'zic' doesn't care which source file contains a Link
758 directive, some downstream uses ran into trouble with the move.
759 (Problem reported by Stephen Colebourne for Joda-Time.)
761 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
762 (problem reported by Chris Walton).
764 Fix 'backzone' typo that linked America/Virgin to the wrong
765 location (problem reported by Michael Deckers).
769 Fix a bug in 'zic -b fat' that caused old timestamps to be
770 mishandled in 32-bit-only readers (problem reported by Daniel
773 Changes to documentation
775 Distribute the SECURITY file (problem reported by Andreas Radke).
778 Release 2021b - 2021-09-24 16:23:00 -0700
781 Jordan now starts DST on February's last Thursday.
782 Samoa no longer observes DST.
783 Merge more location-based Zones whose timestamps agree since 1970.
784 Move some backward-compatibility links to 'backward'.
785 Rename Pacific/Enderbury to Pacific/Kanton.
786 Correct many pre-1993 transitions in Malawi, Portugal, etc.
787 zic now creates each output file or link atomically.
788 zic -L no longer omits the POSIX TZ string in its output.
789 zic fixes for truncation and leap second table expiration.
790 zic now follows POSIX for TZ strings using all-year DST.
791 Fix some localtime crashes and bugs in obscure cases.
792 zdump -v now outputs more-useful boundary cases.
793 tzfile.5 better matches a draft successor to RFC 8536.
796 This release is prompted by recent announcements by Jordan and Samoa.
797 It incorporates many other changes that had accumulated since 2021a.
798 However, it omits most proposed changes that merged all Zones
799 agreeing since 1970, as concerns were raised about doing too many of
800 these changes at once. It does keeps some of these changes in the
801 interest of making tzdb more equitable one step at a time; see
802 "Merge more location-based Zones" below.
804 Changes to future timestamps
806 Jordan now starts DST on February's last Thursday.
807 (Thanks to Steffen Thorsen.)
809 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
813 Rename Pacific/Enderbury to Pacific/Kanton. When we added
814 Enderbury in 1993, we did not know that it is uninhabited and that
815 Kanton (population two dozen) is the only inhabited location in
816 that timezone. The old name is now a backward-compatibility link.
818 Changes to past timestamps
820 Correct many pre-1993 transitions, fixing entries originally
821 derived from Shanks, Whitman, and Mundell. The fixes include:
822 - Barbados: standard time was introduced in 1911, not 1932; and
823 DST was observed in 1942-1944
824 - Cook Islands: In 1899 they switched from east to west of GMT,
825 celebrating Christmas for two days. They (and Niue) switched
826 to standard time in 1952, not 1901.
827 - Guyana: corrected LMT for Georgetown; the introduction of
828 standard time in 1911, not 1915; and corrections to 1975 and
830 - Kanton: uninhabited before 1937-08-31
831 - Niue: only observed -11:20 from 1952 through 1964, then went to
832 -11 instead of -11:30
833 - Portugal: DST was observed in 1950
834 - Tonga: corrected LMT; the introduction of standard time in 1945,
835 not 1901; and corrections to the transition from +12:20 to +13
837 Additional fixes to entries in the 'backzone' file include:
838 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
839 - The Gambia: 1933 and 1942 transitions
840 - Malawi: several 1911 through 1925 transitions
841 - Sierra Leone: several 1913 through 1941 transitions, and DST
842 was NOT observed in 1957 through 1962
843 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
846 Merge more location-based Zones whose timestamps agree since 1970,
847 as pre-1970 timestamps are out of scope. This is part of a
848 process that has been ongoing since 2013. This does not affect
849 post-1970 timestamps, and timezone historians who build with 'make
850 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
851 When merging, keep the most-populous location's data, and move
852 data for other locations to 'backzone' with a backward
853 link in 'backward'. For example, move America/Creston data to
854 'backzone' with a link in 'backward' from America/Phoenix because
855 the two timezones' timestamps agree since 1970; this change
856 affects some pre-1968 timestamps in America/Creston because
857 Creston and Phoenix disagreed before 1968. The affected Zones
858 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
859 America/Creston, America/Curacao, America/Nassau,
860 America/Port_of_Spain, Antarctica/DumontDUrville, and
863 Changes to maintenance procedure
865 The new file SECURITY covers how to report security-related bugs.
867 Several backward-compatibility links have been moved to the
868 'backward' file. These links, which range from Africa/Addis_Ababa
869 to Pacific/Saipan, are only for compatibility with now-obsolete
870 guidelines suggesting an entry for every ISO 3166 code.
871 The intercontinental convenience links Asia/Istanbul and
872 Europe/Nicosia have also been moved to 'backward'.
876 zic now creates each output file or link atomically,
877 possibly by creating a temporary file and then renaming it.
878 This avoids races where a TZ setting would temporarily stop
879 working while zic was installing a replacement file or link.
881 zic -L no longer omits the POSIX TZ string in its output.
882 Starting with 2020a, zic -L truncated its output according to the
883 "Expires" directive or "#expires" comment in the leapseconds file.
884 The resulting TZif files omitted daylight saving transitions after
885 the leap second table expired, which led to far less accurate
886 predictions of times after the expiry. Although future timestamps
887 cannot be converted accurately in the presence of leap seconds, it
888 is more accurate to convert near-future timestamps with a few
889 seconds error than with an hour error, so zic -L no longer
890 truncates output in this way.
892 Instead, when zic -L is given the "Expires" directive, it now
893 outputs the expiration by appending a no-change entry to the leap
894 second table. Although this should work well with most TZif
895 readers, it does not conform to Internet RFC 8536 and some pickier
896 clients (including tzdb 2017c through 2021a) reject it, so
897 "Expires" directives are currently disabled by default. To enable
898 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
899 this new feature it is marked with a new TZif version number 4,
900 a format intended to be documented in a successor to RFC 8536.
901 The old-format "#expires" comments are now treated solely as
902 comments and have no effect on the TZif files.
904 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
905 that omits leap second information for the range LO..B when LO
906 falls between two leap seconds A and B. Instead, it generates a
907 TZif version 4 file that represents the previously missing
910 The TZif reader now allows the leap second table to begin with a
911 correction other than -1 or +1, and to contain adjacent
912 transitions with equal corrections. This supports TZif version 4.
914 The TZif reader now lets leap seconds occur less than 28 days
915 apart. This supports possible future TZif extensions.
917 Fix bug that caused 'localtime' etc. to crash when TZ was
918 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
919 not conform to POSIX but does conform to Internet RFC 8536.
921 Fix another bug that caused 'localtime' etc. to crash when TZ was
922 set to a POSIX-conforming but unusual TZ string like
923 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
925 Fix yet another bug that caused 'localtime' etc. to mishandle slim
926 TZif files containing leap seconds after the last explicit
927 transition in the table, or when handling far-future timestamps
928 in slim TZif files lacking leap seconds.
930 Fix localtime misbehavior involving positive leap seconds.
931 This change affects only behavior for "right" system time,
932 which contains leap seconds, and only if the UT offset is
933 not a multiple of 60 seconds when a positive leap second occurs.
934 (No such timezone exists in tzdb, luckily.) Without the fix,
935 the timestamp was ambiguous during a positive leap second.
936 With the fix, any seconds occurring after a positive leap second
937 and within the same localtime minute are counted through 60, not
938 through 59; their UT offset (tm_gmtoff) is the same as before.
939 Here is how the fix affects timestamps in a timezone with UT
940 offset +01:23:45 (5025 seconds) and with a positive leap second at
941 1972-06-30 23:59:60 UTC (78796800):
943 time_t without the fix with the fix
944 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
945 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
947 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
948 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
950 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
951 civil time changes a few seconds before time_t wraps around, when
952 leap seconds are enabled.
954 Fix bug in zic -r; in some cases, the dummy time type after the
955 last time transition disagreed with the TZ string, contrary to
956 Internet RFC 8563 section 3.3.
958 Fix a bug with 'zic -r @X' when X is a negative leap second that
959 has a nonnegative correction. Without the fix, the output file
960 was truncated so that X appeared to be a positive leap second.
961 Fix a similar, even less likely bug when truncating at a positive
962 leap second that has a nonpositive correction.
964 zic -r now reports an error if given rolling leap seconds, as this
965 usage has never generally worked and is evidently unused.
967 zic now generates a POSIX-conforming TZ string for TZif files
968 where all-year DST is predicted for the indefinite future.
969 For example, for all-year Eastern Daylight Time, zic now generates
970 "XXX3EDT4,0/0,J365/23" where it previously generated
971 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
972 noting the possibility of POSIX conformance.)
974 zic.c no longer requires sys/wait.h (thanks to spazmodius for
975 noting it wasn't needed).
977 When reading slim TZif files, zdump no longer mishandles leap
978 seconds on the rare platforms where time_t counts leap seconds,
979 fixing a bug introduced in 2014g.
981 zdump -v now outputs timestamps at boundaries of what localtime
982 and gmtime can represent, instead of the less useful timestamps
983 one day after the minimum and one day before the maximum.
984 (Thanks to Arthur David Olson for prototype code, and to Manuela
985 Friedrich for debugging help.)
987 zdump's -c and -t options are now consistently inclusive for the
988 lower time bound and exclusive for the upper. Formerly they were
989 inconsistent. (Confusion noted by Martin Burnicki.)
991 Changes to build procedure
993 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
994 non-POSIX hosts where malloc doesn't set errno.
995 (Problem reported by Jan Engelhardt.)
997 Changes to documentation
999 tzfile.5 better matches a draft successor to RFC 8536
1000 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
1003 Release 2021a - 2021-01-24 10:54:57 -0800
1005 Changes to future timestamps
1007 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
1008 (Thanks to Steffen Thorsen.)
1011 Release 2020f - 2020-12-29 00:17:46 -0800
1013 Change to build procedure
1015 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
1016 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
1019 Release 2020e - 2020-12-22 15:14:34 -0800
1022 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
1024 Changes to future timestamps
1026 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
1027 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
1029 Changes to past timestamps
1031 Correct many pre-1986 transitions, fixing entries originally
1032 derived from Shanks. The fixes include:
1033 - Australia: several 1917 through 1971 transitions
1034 - The Bahamas: several 1941 through 1945 transitions
1035 - Bermuda: several 1917 through 1956 transitions
1036 - Belize: several 1942 through 1968 transitions
1037 - Ghana: several 1915 through 1956 transitions
1038 - Israel and Palestine: several 1940 through 1985 transitions
1039 - Kenya and adjacent: several 1908 through 1960 transitions
1040 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
1041 through 1919 transitions
1042 - Seychelles: the introduction of standard time in 1907, not 1906
1043 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
1046 Because of the Australia change, Australia/Currie (King Island) is
1047 no longer needed, as it is identical to Australia/Hobart for all
1048 timestamps since 1970 and was therefore created by mistake.
1049 Australia/Currie has been moved to the 'backward' file and its
1050 corrected data moved to the 'backzone' file.
1052 Changes to past time zone abbreviations and DST flags
1054 To better match legislation in Turks and Caicos, the 2015 shift to
1055 year-round observance of -04 is now modeled as AST throughout before
1056 returning to Eastern Time with US DST in 2018, rather than as
1057 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
1059 Changes to documentation
1061 The zic man page now documents zic's coalescing of transitions
1062 when a zone falls back just before DST springs forward.
1065 Release 2020d - 2020-10-21 11:24:13 -0700
1068 Palestine ends DST earlier than predicted, on 2020-10-24.
1070 Changes to past and future timestamps
1072 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
1073 as previously predicted (thanks to Sharef Mustafa.) Its
1074 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
1075 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
1076 its spring 2020 transition was on March 28 at 00:00, not March 27
1077 (thanks to Pierre Cashon.) This affects Asia/Gaza and
1078 Asia/Hebron. Assume future spring and fall transitions will be on
1079 the Saturday preceding the last Sunday of March and October,
1083 Release 2020c - 2020-10-16 11:15:53 -0700
1086 Fiji starts DST later than usual, on 2020-12-20.
1088 Changes to future timestamps
1090 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
1091 previously predicted. DST will still end on 2021-01-17.
1092 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
1093 the later-than-usual start date is a one-time departure from the
1096 Changes to build procedure
1098 Rearguard tarballs now contain an empty file pacificnew.
1099 Some older downstream software expects this file to exist.
1100 (Problem reported by Mike Cullinan.)
1103 Release 2020b - 2020-10-06 18:35:04 -0700
1106 Revised predictions for Morocco's changes starting in 2023.
1107 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
1108 Macquarie Island has stayed in sync with Tasmania since 2011.
1109 Casey, Antarctica is at +08 in winter and +11 in summer.
1110 zic no longer supports -y, nor the TYPE field of Rules.
1112 Changes to future timestamps
1114 Morocco's spring-forward after Ramadan is now predicted to occur
1115 no sooner than two days after Ramadan, instead of one day.
1116 (Thanks to Milamber.) The first altered prediction is for 2023,
1117 now predicted to spring-forward on April 30 instead of April 23.
1119 Changes to past and future timestamps
1121 Casey Station, Antarctica has been using +08 in winter and +11 in
1122 summer since 2018. The most recent transition from +08 to +11 was
1123 2020-10-04 00:01. Also, Macquarie Island has been staying in
1124 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
1126 Changes to past and future time zone abbreviations and DST flags
1128 Canada's Yukon, represented by America/Whitehorse and
1129 America/Dawson, changes its time zone rules from -08/-07 to
1130 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
1131 This change affects only the time zone abbreviation (MST vs PDT)
1132 and daylight saving flag for the period between the two dates.
1133 (Thanks to Andrew G. Smith.)
1135 Changes to past timestamps
1137 Correct several transitions for Hungary for 1918/1983.
1138 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
1139 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
1140 time was on 11-01, not 10-01 (thanks to Michael Deckers).
1142 The 1891 French transition was on March 16, not March 15. The
1143 1911-03-11 French transition was at midnight, not a minute later.
1144 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
1145 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
1149 Support for zic's long-obsolete '-y YEARISTYPE' option has been
1150 removed and, with it, so has support for the TYPE field in Rule
1151 lines, which is now reserved for compatibility with earlier zic.
1152 These features were previously deprecated in release 2015f.
1153 (Thanks to Tim Parenti.)
1155 zic now defaults to '-b slim' instead of to '-b fat'.
1157 zic's new '-l -' and '-p -' options uninstall any existing
1158 localtime and posixrules files, respectively.
1160 The undocumented and ineffective tzsetwall function has been
1163 Changes to build procedure
1165 The Makefile now defaults POSIXRULES to '-', so the posixrules
1166 feature (obsolete as of 2019b) is no longer installed by default.
1168 Changes to documentation and commentary
1170 The long-obsolete files pacificnew, systemv, and yearistype.sh have
1171 been removed from the distribution. (Thanks to Tim Parenti.)
1174 Release 2020a - 2020-04-23 16:03:47 -0700
1177 Morocco springs forward on 2020-05-31, not 2020-05-24.
1178 Canada's Yukon advanced to -07 year-round on 2020-03-08.
1179 America/Nuuk renamed from America/Godthab.
1180 zic now supports expiration dates for leap second lists.
1182 Changes to future timestamps
1184 Morocco's second spring-forward transition in 2020 will be May 31,
1185 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
1186 Adjust future-year predictions to use the first Sunday after the
1187 day after Ramadan, not the first Sunday after Ramadan.
1189 Canada's Yukon, represented by America/Whitehorse and
1190 America/Dawson, advanced to -07 year-round, beginning with its
1191 spring-forward transition on 2020-03-08, and will not fall back on
1192 2020-11-01. Although a government press release calls this
1193 "permanent Pacific Daylight Saving Time", we prefer MST for
1194 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
1195 (Thanks to Tim Parenti.)
1197 Changes to past timestamps
1199 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
1201 Changes to timezone identifiers
1203 To reflect current usage in English better, America/Godthab has
1204 been renamed to America/Nuuk. A backwards-compatibility link
1205 remains for the old name.
1209 localtime.c no longer mishandles timestamps after the last
1210 transition in a TZif file with leap seconds and with daylight
1211 saving time transitions projected into the indefinite future.
1212 For example, with TZ='America/Los_Angeles' with leap seconds,
1213 zdump formerly reported a DST transition on 2038-03-14
1214 from 01:59:32.999... to 02:59:33 instead of the correct transition
1215 from 01:59:59.999... to 03:00:00.
1217 zic -L now supports an Expires line in the leapseconds file, and
1218 truncates the TZif output accordingly. This propagates leap
1219 second expiration information into the TZif file, and avoids the
1220 abovementioned localtime.c bug as well as similar bugs present in
1221 many client implementations. If no Expires line is present, zic
1222 -L instead truncates the TZif output based on the #expires comment
1223 present in leapseconds files distributed by tzdb 2018f and later;
1224 however, this usage is obsolescent. For now, the distributed
1225 leapseconds file has an Expires line that is commented out, so
1226 that the file can be fed to older versions of zic which ignore the
1227 commented-out line. Future tzdb distributions are planned to
1228 contain a leapseconds file with an Expires line.
1230 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
1231 set to 1 if the system library supports the feature, and 2 if not.
1232 As before, these macros are nonzero if tzcode should support the
1233 feature, zero otherwise.
1235 The configuration macro ALTZONE now has the same values with the
1236 same meaning as HAVE_TZNAME and USG_COMPAT.
1238 The code's defense against CRLF in leap-seconds.list is now
1239 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
1241 Although the undocumented tzsetwall function is not changed in
1242 this release, it is now deprecated in preparation for removal in
1243 future releases. Due to POSIX requirements, tzsetwall has not
1244 worked for some time. Any code that uses it should instead use
1245 tzalloc(NULL) or, if portability trumps thread-safety, should
1246 unset the TZ environment variable.
1248 Changes to commentary
1250 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
1251 following America/Halifax, and comments about Yukon's "south" and
1252 "north" have been corrected to say "east" and "west". (Thanks to
1256 Release 2019c - 2019-09-11 08:59:48 -0700
1259 Fiji observes DST from 2019-11-10 to 2020-01-12.
1260 Norfolk Island starts observing Australian-style DST.
1262 Changes to future timestamps
1264 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
1265 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
1266 Adjust future guesses accordingly.
1268 Norfolk Island will observe Australian-style DST starting in
1269 spring 2019. The first transition is on 2019-10-06. (Thanks to
1270 Kyle Czech and Michael Deckers.)
1272 Changes to past timestamps
1274 Many corrections to time in Turkey from 1940 through 1985.
1275 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
1277 The Norfolk Island 1975-03-02 transition was at 02:00 standard
1278 time, not 02:00 DST. (Thanks to Michael Deckers.)
1280 South Korea observed DST from 1948 through 1951. Although this
1281 info was supposed to appear in release 2014j, a typo inadvertently
1282 suppressed the change. (Thanks to Alois Treindl.)
1284 Detroit observed DST in 1967 and 1968 following the US DST rules,
1285 except that its 1967 DST began on June 14 at 00:01. (Thanks to
1286 Alois Treindl for pointing out that the old data entries were
1289 Fix several errors in pre-1970 transitions in Perry County, IN.
1290 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
1292 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
1293 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
1294 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
1295 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
1296 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
1297 Königsberg switched to +03 on 04-07 not 01-01.
1299 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
1300 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
1301 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
1303 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
1304 (Thanks to Michael Deckers.)
1306 Changes to past time zone abbreviations and DST flags
1308 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
1309 is now flagged as DST and is abbreviated HKWT not HKT.
1313 leapseconds.awk now relies only on its input data, rather than
1314 also relying on its comments. (Inspired by code from Dennis
1315 Ferguson and Chris Woodbury.)
1317 The code now defends against CRLFs in leap-seconds.list.
1318 (Thanks to Brian Inglis and Chris Woodbury.)
1320 Changes to documentation and commentary
1322 theory.html discusses leap seconds. (Thanks to Steve Summit.)
1324 Nashville's newspapers dueled about the time of day in the 1950s.
1325 (Thanks to John Seigenthaler.)
1327 Liechtenstein observed Swiss DST in 1941/2.
1328 (Thanks to Alois Treindl.)
1331 Release 2019b - 2019-07-01 00:09:53 -0700
1334 Brazil no longer observes DST.
1335 'zic -b slim' outputs smaller TZif files; please try it out.
1336 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
1338 Changes to future timestamps
1340 Brazil has canceled DST and will stay on standard time indefinitely.
1341 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
1344 Predictions for Morocco now go through 2087 instead of 2037, to
1345 work around a problem on newlib when using TZif files output by
1346 zic 2019a or earlier. (Problem reported by David Gauchard.)
1348 Changes to past and future timestamps
1350 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
1351 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
1352 future transitions to be March's last Friday at 00:00.
1354 Changes to past timestamps
1356 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
1357 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
1358 not 09-15 at 00:00. In 1946 its spring-forward transition was on
1359 04-21 at 00:00, not the previous day at 03:30. From 1946 through
1360 1952 its fall-back transitions occurred at 04:30, not at 03:30.
1361 In 1947 its fall-back transition was on 11-30, not 12-30.
1364 Changes to past time zone abbreviations
1366 Italy's 1866 transition to Rome Mean Time was on December 12, not
1367 September 22. This affects only the time zone abbreviation for
1368 Europe/Rome between those dates. (Thanks to Stephen Trainor and
1371 Changes affecting metadata only
1373 Add info about the Crimea situation in zone1970.tab and zone.tab.
1374 (Problem reported by Serhii Demediuk.)
1378 zic's new -b option supports a way to control data bloat and to
1379 test for year-2038 bugs in software that reads TZif files.
1380 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
1381 for example, changing from fat to slim shrinks the Europe/London
1382 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
1383 files represent the same set of timestamps and use the same TZif
1384 format as documented in tzfile(5) and in Internet RFC 8536.
1385 Fat format attempts to work around bugs or incompatibilities in
1386 older software, notably software that mishandles 64-bit TZif data
1387 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
1388 Slim format is more efficient and does not work around 64-bit bugs
1389 or obsolete TZ strings. Currently zic defaults to fat format
1390 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
1391 out-of-the-box default is intended to change in future releases
1392 as the buggy software often mishandles timestamps anyway.
1394 zic no longer treats a set of rules ending in 2037 specially.
1395 Previously, zic assumed that such a ruleset meant that future
1396 timestamps could not be predicted, and therefore omitted a
1397 POSIX-like TZ string in the TZif output. The old behavior is no
1398 longer needed for current tzdata, and caused problems with newlib
1399 when used with older tzdata (reported by David Gauchard).
1401 zic no longer generates some artifact transitions. For example,
1402 Europe/London no longer has a no-op transition in January 1996.
1404 Changes to build procedure
1406 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
1409 Changes to documentation and commentary
1411 The Makefile now documents the POSIXRULES macro as being obsolete,
1412 and similarly, zic's -p POSIXRULES option is now documented as
1413 being obsolete. Although the POSIXRULES feature still exists and
1414 works as before, in practice it is rarely used for its intended
1415 purpose, and it does not work either in the default reference
1416 implementation (for timestamps after 2037) or in common
1417 implementations such as GNU/Linux (for contemporary timestamps).
1418 Since POSIXRULES was designed primarily as a temporary transition
1419 facility for System V platforms that died off decades ago, it is
1420 being decommissioned rather than institutionalized.
1422 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
1425 Release 2019a - 2019-03-25 22:01:33 -0700
1428 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
1429 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
1431 Changes to past and future timestamps
1433 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
1434 previously predicted. Adjust our prediction by guessing that spring
1435 transitions will be between 24 and 30 March, which matches recent practice
1436 since 2016. (Thanks to Even Scharning and Tim Parenti.)
1438 Metlakatla ended its observance of Pacific standard time,
1439 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
1440 Stanley and Tim Parenti.)
1442 Changes to past timestamps
1444 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
1445 (Thanks to Alois Treindl and Isaac Starkman.)
1447 Changes to time zone abbreviations
1449 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
1450 of being a separate zone that generates the abbreviation "UCT",
1451 which nowadays is typically a typo. (Problem reported by Isiah
1456 zic now has an -r option to limit the time range of output data.
1457 For example, 'zic -r @1000000000' limits the output data to
1458 timestamps starting 1000000000 seconds after the Epoch.
1459 This helps shrink output size and can be useful for applications
1460 not needing the full timestamp history, such as TZDIST truncation;
1461 see Internet RFC 8536 section 5.1. (Inspired by a feature request
1462 from Christopher Wong, helped along by bug reports from Wong and
1465 Changes to documentation
1467 Mention Internet RFC 8536 (February 2019), which documents TZif.
1469 tz-link.html now cites tzdata-meta
1470 <https://tzdata-meta.timtimeonline.com/>.
1473 Release 2018i - 2018-12-30 11:05:43 -0800
1476 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
1478 Changes to future timestamps
1480 Due to a change in government, São Tomé and Príncipe switches back
1481 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
1482 Nasardinov and Michael Deckers.)
1485 Release 2018h - 2018-12-23 17:59:32 -0800
1488 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
1489 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
1490 Metlakatla, Alaska observes PST this winter only.
1491 Guess Morocco will continue to adjust clocks around Ramadan.
1492 Add predictions for Iran from 2038 through 2090.
1494 Changes to future timestamps
1496 Guess that Morocco will continue to fall back just before and
1497 spring forward just after Ramadan, the practice since 2012.
1498 (Thanks to Maamar Abdelkader.) This means Morocco will observe
1499 negative DST during Ramadan in main and vanguard formats, and in
1500 rearguard format it stays in the +00 timezone and observes
1501 ordinary DST in all months other than Ramadan. As before, extend
1502 this guesswork to the year 2037. As a consequence, Morocco is
1503 scheduled to observe three DST transitions in some Gregorian years
1504 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
1507 The table of exact transitions for Iranian DST has been extended.
1508 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
1509 It now cuts off before 2091 as there is doubt about how the Persian
1510 calendar will treat 2091. This change predicts DST transitions in
1511 2038-9, 2042-3, and 2046-7 to occur one day later than previously
1512 predicted. As before, post-cutoff transitions are approximated.
1514 Changes to past and future timestamps
1516 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
1517 +05 on 2018-12-21. This is a zone split as Qostanay (aka
1518 Kostanay) did not switch, so create a zone Asia/Qostanay.
1520 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
1521 It did not change clocks that day and remains on -08 this winter.
1522 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
1523 rules next spring, so this change affects only timestamps
1524 from 2018-11-04 through 2019-03-10.
1526 Change to past timestamps
1528 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
1529 not 00:00. I transcribed the time incorrectly from Shanks.
1530 (Thanks to Phake Nick.)
1532 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
1533 (Thanks to Phake Nick.)
1535 Guam observed DST irregularly from 1959 through 1977.
1536 (Thanks to Phake Nick.)
1538 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
1539 10-01 changed standard time to +08:30 (not +08). Its transition
1540 back to +08 after WWII was on 1945-09-15, not the previous day.
1541 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
1542 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1543 its 1952 fallback was on 11-02 (not 10-25).
1545 This release contains many changes to timestamps before 1946 due
1546 to Japanese possession or occupation of Pacific/Chuuk,
1547 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1548 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1549 (Thanks to Phake Nick.)
1551 Assume that the Spanish East Indies was like the Philippines and
1552 observed American time until the end of 1844. This affects
1553 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1555 Changes to past tm_isdst flags
1557 For the recent Morocco change, the tm_isdst flag should be 1 from
1558 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1559 Give a URL to the official decree. (Thanks to Matt Johnson.)
1562 Release 2018g - 2018-10-26 22:22:45 -0700
1565 Morocco switches to permanent +01 on 2018-10-28.
1567 Changes to future timestamps
1569 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1570 so its clocks will not fall back as previously scheduled.
1571 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1575 When generating TZif files with leap seconds, zic no longer uses a
1576 format that trips up older 32-bit clients, fixing a bug introduced
1577 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1578 for QTBUG-53071 now also works for TZif files with leap seconds.
1580 The translator to rearguard format now rewrites the line
1581 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1582 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1583 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1584 and earlier. (Reported by Christos Zoulas.)
1586 Changes to past time zone abbreviations
1588 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1589 This reverts to 2011h, as the abbreviation change in 2011i was
1592 Changes to documentation
1594 tzfile.5 has new sections on interoperability issues.
1597 Release 2018f - 2018-10-18 00:14:18 -0700
1600 Volgograd moves from +03 to +04 on 2018-10-28.
1601 Fiji ends DST 2019-01-13, not 2019-01-20.
1602 Most of Chile changes DST dates, effective 2019-04-06.
1604 Changes to future timestamps
1606 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1607 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1609 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1610 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1613 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1614 time, and resume DST on the first Saturday in September at 24:00 mainland
1615 time. The changes are effective from 2019-04-06, and do not affect the
1616 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1617 and Tim Parenti.) Adjust future predictions accordingly.
1619 Changes to past timestamps
1621 The 2018-05-05 North Korea 30-minute time zone change took place
1622 at 23:30 the previous day, not at 00:00 that day.
1624 China's 1988 spring-forward transition was on April 17, not
1625 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1628 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1629 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1630 temporarily switched to +09/+10 during World War II. Macau
1631 observed DST in 1942/79, not 1961/80, and there were several
1632 errors for transition times and dates. (Thanks to P Chan.)
1634 The 1948-1951 fallback transitions in Japan were at 25:00 on
1635 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1636 zic turns this into 01:00 on the day after September's second
1637 Saturday, which is the best that POSIX or C platforms can do.
1639 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1640 paper by Li Yu, replacing more-questionable data from Shanks.
1642 Changes to time zone abbreviations
1644 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1648 zic now always generates TZif files where time type 0 is used for
1649 timestamps before the first transition. This simplifies the
1650 reading of TZif files and should not affect behavior of existing
1651 TZif readers because the same set of time types is used; only
1652 their internal indexes may have changed. This affects only the
1653 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1654 EET, which previously used nonzero types for these timestamps.
1656 Because of the type 0 change, zic no longer outputs a dummy
1657 transition at time -2**59 (before the Big Bang), as clients should
1658 no longer need this to handle historical timestamps correctly.
1659 This reverts a change introduced in 2013d and shrinks most TZif
1660 files by a few bytes.
1662 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1663 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1664 occurs at 18:00 on the Saturday before the last Sunday in April.
1665 This behavior was documented in 2018a but the code did not
1666 entirely match the documentation.
1668 localtime.c no longer requires at least one time type in TZif
1669 files that lack transitions or have a POSIX-style TZ string. This
1670 future-proofs the code against possible future extensions to the
1671 format that would allow TZif files with POSIX-style TZ strings and
1672 without transitions or time types.
1674 A read-access subscript error in localtime.c has been fixed.
1675 It could occur only in TZif files with timecnt == 0, something that
1676 does not happen in practice now but could happen in future versions.
1678 localtime.c no longer ignores TZif POSIX-style TZ strings that
1679 specify only standard time. Instead, these TZ strings now
1680 override the default time type for timestamps after the last
1681 transition (or for all timestamps if there are no transitions),
1682 just as DST strings specifying DST have always done.
1684 leapseconds.awk now outputs "#updated" and "#expires" comments,
1685 and supports leap seconds at the ends of months other than June
1686 and December. (Inspired by suggestions from Chris Woodbury.)
1688 Changes to documentation
1690 New restrictions: A Rule name must start with a character that
1691 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1692 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1693 The latter restriction makes room for future extensions (a
1694 possibility noted by Tom Lane).
1696 tzfile.5 now documents what time types apply before the first and
1697 after the last transition, if any.
1699 Documentation now uses the spelling "timezone" for a TZ setting
1700 that determines timestamp history, and "time zone" for a
1701 geographic region currently sharing the same standard time.
1703 The name "TZif" is now used for the tz binary data format.
1705 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1706 (Thanks to Aldrin Martoq for the link.)
1708 Changes to build procedure
1710 New 'make' target 'rearguard_tarballs' to build the rearguard
1711 tarball only. This is a convenience on platforms that lack lzip
1712 if you want to build the rearguard tarball. (Problem reported by
1715 tzdata.zi is now more stable from release to release. (Problem
1716 noted by Tom Lane.) It is also a bit shorter.
1718 tzdata.zi now can contain comment lines documenting configuration
1719 information, such as which data format was selected, which input
1720 files were used, and how leap seconds are treated. (Problems
1721 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1722 are used these comment lines are absent, for backward
1723 compatibility. A redistributor intending to alter its copy of the
1724 files should also append "-LABEL" to the 'version' file's first
1725 line, where "LABEL" identifies the redistributor's change.
1728 Release 2018e - 2018-05-01 23:42:51 -0700
1732 North Korea switches back to +09 on 2018-05-05.
1733 The main format uses negative DST again, for Ireland etc.
1734 'make tarballs' now also builds a rearguard tarball.
1735 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1737 Changes to past and future timestamps
1739 North Korea switches back from +0830 to +09 on 2018-05-05.
1740 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1743 Bring back the negative-DST changes of 2018a, except be more
1744 compatible with data parsers that do not support negative DST.
1745 Also, this now affects historical timestamps in Namibia and the
1746 former Czechoslovakia, not just Ireland. The main format now uses
1747 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1748 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1749 does not affect UT offsets, only time zone abbreviations and the
1750 tm_isdst flag. Also, this does not affect rearguard or vanguard
1751 formats; effectively the main format now uses vanguard instead of
1752 rearguard format. Data parsers that do not support negative DST
1753 can still use data from the rearguard tarball described below.
1755 Changes to build procedure
1757 The command 'make tarballs' now also builds the tarball
1758 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1759 except that it uses rearguard format intended for trailing-edge
1762 Changes to data format and to code
1764 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1765 suffix, which specifies whether the adjusted time is standard time
1766 or daylight saving time. If no suffix is given, daylight saving
1767 time is used if and only if the SAVE column is nonzero; this is
1768 the longstanding behavior. Although this new feature is not used
1769 in tzdata, it could be used to specify the legal time in Namibia
1770 1994-2017, as opposed to the popular time (see below).
1772 Changes to past timestamps
1774 From 1994 through 2017 Namibia observed DST in winter, not summer.
1775 That is, it used negative DST, as Ireland still does. This change
1776 does not affect UTC offsets; it affects only the tm_isdst flag and
1777 the abbreviation used during summer, which is now CAT, not WAST.
1778 Although (as noted by Michael Deckers) summer and winter time were
1779 both simply called "standard time" in Namibian law, in common
1780 practice winter time was considered to be DST (as noted by Stephen
1781 Colebourne). The full effect of this change is only in vanguard
1782 and main format; in rearguard format, the tm_isdst flag is still
1783 zero in winter and nonzero in summer.
1785 In 1946/7 Czechoslovakia also observed negative DST in winter.
1786 The full effect of this change is only in vanguard and main
1787 formats; in rearguard format, it is modeled as plain GMT without
1788 daylight saving. Also, the dates of some 1944/5 DST transitions
1789 in Czechoslovakia have been changed.
1792 Release 2018d - 2018-03-22 07:05:46 -0700
1796 Palestine starts DST a week earlier in 2018.
1797 Add support for vanguard and rearguard data consumers.
1798 Add subsecond precision to source data format, though not to data.
1800 Changes to future timestamps
1802 In 2018, Palestine starts DST on March 24, not March 31.
1803 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1805 Changes to past and future timestamps
1807 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1808 at 04:00. (Thanks to Steffen Thorsen.)
1810 Changes to past timestamps
1812 Historical transitions for Uruguay, represented by
1813 America/Montevideo, have been updated per official legal documents,
1814 replacing previous data mainly originating from the inventions of
1815 Shanks & Pottenger. This has resulted in adjustments ranging from
1816 30 to 90 minutes in either direction over at least two dozen
1817 distinct periods ranging from one day to several years in length.
1818 A mere handful of pre-1991 transitions are unaffected; data since
1819 then has come from more reliable contemporaneous reporting. These
1820 changes affect various timestamps in 1920-1923, 1936, 1939,
1821 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1822 Additionally, Uruguay's pre-standard-time UT offset has been
1823 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1824 match the location of the Observatory of the National Meteorological
1825 Institute in Montevideo.
1826 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1828 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1829 (Thanks to Kerry Shetline.)
1831 Fix the 1912-01-01 transition for Portugal and its colonies.
1832 This transition was at 00:00 according to the new UT offset, not
1833 according to the old one. Also assume that Cape Verde switched on
1834 the same date as the rest, not in 1907. This affects
1835 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1836 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1837 (Thanks to Michael Deckers.)
1839 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1842 Changes to past time zone abbreviations
1844 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1845 is no clock change associated with the transition.
1847 Changes to build procedure
1849 The new DATAFORM macro in the Makefile lets the installer choose
1850 among three source data formats. The idea is to lessen downstream
1851 disruption when data formats are improved.
1853 * DATAFORM=vanguard installs from the latest, bleeding-edge
1854 format. DATAFORM=main (the default) installs from the format
1855 used in the 'africa' etc. files. DATAFORM=rearguard installs
1856 from a trailing-edge format. Eventually, elements of today's
1857 vanguard format should move to the main format, and similarly
1858 the main format's features should eventually move to the
1861 * In the current version, the main and rearguard formats are
1862 identical and match that of 2018c, so this change does not
1863 affect default behavior. The vanguard format currently contains
1864 one feature not in the main format: negative SAVE values. This
1865 improves support for Ireland, which uses Irish Standard Time
1866 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1867 supported negative SAVE values for decades, and this feature
1868 should move to the main format soon. However, it will not move
1869 to the rearguard format for quite some time because some
1870 downstream parsers do not support it.
1872 * The build procedure constructs three files vanguard.zi, main.zi,
1873 and rearguard.zi, one for each format. Although the files
1874 represent essentially the same data, they may have minor
1875 discrepancies that users are not likely to notice. The files
1876 are intended for downstream data consumers and are not
1877 installed. Zoneinfo parsers that do not support negative SAVE values
1878 should start using rearguard.zi, so that they will be unaffected
1879 when the negative-DST feature moves from vanguard to main.
1880 Bleeding-edge Zoneinfo parsers that support the new features
1881 already can use vanguard.zi; in this respect, current tzcode is
1884 The Makefile should now be safe for parallelized builds, and 'make
1885 -j to2050new.tzs' is now much faster on a multiprocessor host
1888 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1889 prepends TZDIR/ to file names that do not begin with '/'. This is
1890 not recommended for general use, due to its security implications.
1891 (From a suggestion by Manuela Friedrich.)
1895 zic now accepts subsecond precision in expressions like
1896 00:19:32.13, which is approximately the legal time of the
1897 Netherlands from 1835 to 1937. However, because it is
1898 questionable whether the few recorded uses of non-integer offsets
1899 had subsecond precision in practice, there are no plans for tzdata
1900 to use this feature. (Thanks to Steve Allen for pointing out
1901 the limitations of historical data in this area.)
1903 The code is a bit more portable to MS-Windows. Installers can
1904 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1905 reserve identifiers like 'localtime'. (Thanks to Manuela
1908 Changes to documentation and commentary
1910 theory.html now outlines tzdb's extensions to POSIX's model for
1911 civil time, and has a section "POSIX features no longer needed"
1912 that lists POSIX API components that are now vestigial.
1913 (From suggestions by Steve Summit.) It also better distinguishes
1914 time zones from tz regions. (From a suggestion by Guy Harris.)
1916 Commentary is now more consistent about using the phrase "daylight
1917 saving time", to match the C name tm_isdst. Daylight saving time
1918 need not occur in summer, and need not have a positive offset from
1921 Commentary about historical transitions in Uruguay has been expanded
1922 with links to many relevant legal documents.
1923 (Thanks to Tim Parenti.)
1925 Commentary now uses some non-ASCII characters with Unicode value
1926 less than U+0100, as they can be useful and should work even with
1927 older editors such as XEmacs.
1930 Release 2018c - 2018-01-22 23:00:44 -0800
1933 Revert Irish changes that relied on negative SAVE values.
1937 Revert the 2018a change to Europe/Dublin. As before, this change
1938 does not affect UT offsets or abbreviations; it affects only
1939 whether timestamps are considered to be standard time or
1940 daylight-saving time, as expressed in the tm_isdst flag of C's
1941 struct tm type. This reversion is intended to be a temporary
1942 workaround for problems discovered with downstream uses of
1943 releases 2018a and 2018b, which implemented Irish time by using
1944 negative SAVE values in the Eire rules of the 'europe' file.
1945 Although negative SAVE values have been part of tzcode for many
1946 years and are supported by many platforms, they were not
1947 documented before 2018a and ICU and OpenJDK do not currently
1948 support them. A mechanism to export data to platforms lacking
1949 support for negative DST is planned to be developed before the
1950 change is reapplied. (Problems reported by Deborah Goldsmith and
1951 Stephen Colebourne.)
1953 Changes to past timestamps
1955 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1956 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1958 Changes to build procedure
1960 The build procedure now works around mawk 1.3.3's lack of support
1961 for character class expressions. (Problem reported by Ohyama.)
1964 Release 2018b - 2018-01-17 23:24:48 -0800
1967 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1969 Changes to build procedure
1971 The distribution now contains the file 'pacificnew' again.
1972 This file was inadvertently omitted in the 2018a distribution.
1973 (Problem reported by Matias Fonzo.)
1976 Release 2018a - 2018-01-12 22:29:21 -0800
1979 São Tomé and Príncipe switched from +00 to +01.
1980 Brazil's DST will now start on November's first Sunday.
1981 Ireland's standard time is now in the summer, not the winter.
1982 Use Debian-style installation locations, instead of 4.3BSD-style.
1985 Changes to past and future timestamps
1987 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1988 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1990 Changes to future timestamps
1992 Starting in 2018 southern Brazil will begin DST on November's
1993 first Sunday instead of October's third Sunday. (Thanks to
1996 Changes to past timestamps
1998 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1999 been corrected. The 'backzone' and 'zone.tab' files did not agree
2000 with the 'africa' and 'zone1970.tab' files. (Problem reported by
2003 The abbreviation invented for Bolivia Summer Time (1931-2) is now
2004 BST instead of BOST, to be more consistent with the convention
2005 used for Latvian Summer Time (1918-9) and for British Summer Time.
2009 Change Europe/Dublin so that it observes Irish Standard Time (UT
2010 +01) in summer and GMT (as negative daylight-saving) in winter,
2011 instead of observing standard time (GMT) in winter and Irish
2012 Summer Time (UT +01) in summer. This change does not affect UT
2013 offsets or abbreviations; it affects only whether timestamps are
2014 considered to be standard time or daylight-saving time, as
2015 expressed in the tm_isdst flag of C's struct tm type.
2016 (Discrepancy noted by Derick Rethans.)
2018 Changes to build procedure
2020 The default installation locations have been changed to mostly
2021 match Debian circa 2017, instead of being designed as an add-on to
2022 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
2023 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
2024 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
2025 locations more precisely. (This responds to suggestions from
2026 Brian Inglis and from Steve Summit.)
2028 The default installation procedure no longer creates the
2029 backward-compatibility link US/Pacific-New, which causes
2030 confusion during user setup (e.g., see Debian bug 815200).
2031 Use 'make BACKWARD="backward pacificnew"' to create the link
2032 anyway, for now. Eventually we plan to remove the link entirely.
2034 tzdata.zi now contains a version-number comment.
2035 (Suggested by Tom Lane.)
2037 The Makefile now quotes values like BACKWARD more carefully when
2038 passing them to the shell. (Problem reported by Zefram.)
2040 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
2041 that have snprintf and use pre-C99 compilers. (Problem reported
2046 zic has a new option -t FILE that specifies the location of the
2047 file that determines local time when TZ is unset. The default for
2048 this location can be configured via the new TZDEFAULT makefile
2049 macro, which defaults to /etc/localtime.
2051 Diagnostics and commentary now distinguish UT from UTC more
2052 carefully; see theory.html for more information about UT vs UTC.
2054 zic has been ported to GCC 8's -Wstringop-truncation option.
2055 (Problem reported by Martin Sebor.)
2057 Changes to documentation and commentary
2059 The zic man page now documents the longstanding behavior that
2060 times and years can be out of the usual range, with negative times
2061 counting backwards from midnight and with year 0 preceding year 1.
2062 (Problem reported by Michael Deckers.)
2064 The theory.html file now mentions the POSIX limit of six chars
2065 per abbreviation, and lists alphabetic abbreviations used.
2067 The files tz-art.htm and tz-link.htm have been renamed to
2068 tz-art.html and tz-link.html, respectively, for consistency with
2069 other file names and to simplify web server configuration.
2072 Release 2017c - 2017-10-20 14:49:34 -0700
2075 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
2076 Fiji ends DST 2018-01-14, not 2018-01-21.
2077 Namibia switches from +01/+02 to +02 on 2018-04-01.
2078 Sudan switches from +03 to +02 on 2017-11-01.
2079 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
2080 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
2081 A new file tzdata.zi now holds a small text copy of all data.
2082 The zic input format has been regularized slightly.
2084 Changes to future timestamps
2086 Northern Cyprus has decided to resume EU rules starting
2087 2017-10-29, thus reinstituting winter time.
2089 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
2090 predicted. (Thanks to Dominic Fok.) Adjust future predictions
2093 Namibia will switch from +01 with DST to +02 all year on
2094 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
2095 at 02:00. (Thanks to Steffen Thorsen.)
2097 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
2098 Atyya and Yahia Abdalla.) South Sudan is not switching, so
2099 Africa/Juba is no longer a link to Africa/Khartoum.
2101 Tonga has likely ended its experiment with DST, and will not
2102 adjust its clocks on 2017-11-05. Although Tonga has not announced
2103 whether it will continue to observe DST, the IATA is assuming that
2104 it will not. (Thanks to David Wade.)
2106 Turks & Caicos will switch from -04 all year to -05 with US DST on
2107 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
2108 at 02:00. (Thanks to Steffen Thorsen.)
2110 Changes to past timestamps
2112 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
2113 (Thanks to Arthur David Olson.)
2115 Detroit did not observe DST in 1967.
2117 Use railway time for Asia/Kolkata before 1941, by switching to
2118 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
2119 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
2121 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
2122 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
2124 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
2125 American time in 1892, not 1879. (Thanks to Michael Deckers.)
2127 Adjust the 1867 transition in Alaska to better reflect the
2128 historical record, by changing it to occur on 1867-10-18 at 15:30
2129 Sitka time rather than at the start of 1867-10-17 local time.
2130 Although strictly speaking this is accurate only for Sitka,
2131 the rest of Alaska's blanks need to be filled in somehow.
2133 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
2134 (Thanks to Michael Deckers.)
2136 Add 7 s to the UT offset in Asia/Yangon before 1920.
2138 Changes to zone names
2140 Remove Canada/East-Saskatchewan from the 'backward' file, as it
2141 exceeded the 14-character limit and was an unused misnomer anyway.
2143 Changes to build procedure
2145 To support applications that prefer to read time zone data in text
2146 form, two zic input files tzdata.zi and leapseconds are now
2147 installed by default. The commands 'zic tzdata.zi' and 'zic -L
2148 leapseconds tzdata.zi' can reproduce the tzdata binary files
2149 without and with leap seconds, respectively. To prevent these two
2150 new files from being installed, use 'make TZDATA_TEXT=', and to
2151 suppress leap seconds from the tzdata text installation, use 'make
2152 TZDATA_TEXT=tzdata.zi'.
2154 'make BACKWARD=' now suppresses backward-compatibility names
2155 like 'US/Pacific' that are defined in the 'backward' and
2158 'make check' now works on systems that lack a UTF-8 locale,
2159 or that lack the nsgmls program. Set UTF8_LOCALE to configure
2160 the name of a UTF-8 locale, if you have one.
2162 Y2K runtime checks are no longer enabled by default. Add
2163 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
2164 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
2165 to disable them. (New name suggested by Brian Inglis.)
2167 The build procedure for zdump now works on AIX 7.1.
2168 (Problem reported by Kees Dekker.)
2172 zic and the reference runtime now reject multiple leap seconds
2173 within 28 days of each other, or leap seconds before the Epoch.
2174 As a result, support for double leap seconds, which was
2175 obsolescent and undocumented, has been removed. Double leap
2176 seconds were an error in the C89 standard; they have never existed
2177 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
2178 noticing glitches in the code that uncovered this problem.)
2180 zic now warns about use of the obsolescent and undocumented -y
2181 option, and about use of the obsolescent TYPE field of Rule lines.
2183 zic now allows unambiguous abbreviations like "Sa" and "Su" for
2184 weekdays; formerly it rejected them due to a bug. Conversely, zic
2185 no longer considers non-prefixes to be abbreviations; for example,
2186 it no longer accepts "lF" as an abbreviation for "lastFriday".
2187 Also, zic warns about the undocumented usage with a "last-"
2188 prefix, e.g., "last-Fri".
2190 Similarly, zic now accepts the unambiguous abbreviation "L" for
2191 "Link" in ordinary context and for "Leap" in leap-second context.
2192 Conversely, zic no longer accepts non-prefixes such as "La" as
2193 abbreviations for words like "Leap".
2195 zic no longer accepts leap second lines in ordinary input, or
2196 ordinary lines in leap second input. Formerly, zic sometimes
2197 warned about this undocumented usage and handled it incorrectly.
2199 The new macro HAVE_TZNAME governs whether the tzname external
2200 variable is exported, instead of USG_COMPAT. USG_COMPAT now
2201 governs only the external variables "timezone" and "daylight".
2202 This change is needed because the three variables are not in the
2203 same category: although POSIX requires tzname, it specifies the
2204 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
2205 if not defined, the code attempts to guess it from other macros.
2207 localtime.c and difftime.c no longer require stdio.h, and .c files
2208 other than zic.c no longer require sys/wait.h.
2210 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
2212 Calculation of time_t extrema works around a bug in GCC 4.8.4
2213 (Reported by Stan Shebs and Joseph Myers.)
2215 zic.c no longer mistranslates formats of line numbers in non-English
2216 locales. (Problem reported by Benno Schulenberg.)
2218 Several minor changes have been made to the code to make it a
2219 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
2220 Dekker for reporting the problems.)
2222 Changes to documentation and commentary
2224 The two new files 'theory.html' and 'calendars' contain the
2225 contents of the removed file 'Theory'. The goal is to document
2226 tzdb theory more accessibly.
2228 The zic man page now documents abbreviation rules.
2230 tz-link.htm now covers how to apply tzdata changes to clients.
2231 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
2233 The leap-seconds.list URL has been updated to something that is
2234 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
2236 Release 2017b - 2017-03-17 07:30:38 -0700
2238 Briefly: Haiti has resumed DST.
2240 Changes to past and future timestamps
2242 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
2244 Changes to past timestamps
2246 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
2248 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
2249 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
2253 The reference localtime implementation now falls back on the
2254 current US daylight-saving transition rules rather than the
2255 1987-2006 rules. This fallback occurs only when (1) the TZ
2256 environment variable has a value like "AST4ADT" that asks
2257 for daylight saving time but does not specify the rules, (2) there
2258 is no file by that name, and (3) the TZDEFRULES file cannot be
2259 loaded. (Thanks to Tom Lane.)
2262 Release 2017a - 2017-02-28 00:05:36 -0800
2264 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
2267 Changes to future timestamps
2269 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
2271 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
2272 Its clocks diverge from America/Santiago starting 2017-05-13 at
2273 23:00, hiving off a new zone America/Punta_Arenas. Although the
2274 Chilean government says this change expires in May 2019, for now
2275 assume it's permanent. (Thanks to Juan Correa and Deborah
2276 Goldsmith.) This also affects Antarctica/Palmer.
2278 Changes to past timestamps
2280 Fix many entries for historical timestamps for Europe/Madrid
2281 before 1979, to agree with tables compiled by Pere Planesas of the
2282 National Astronomical Observatory of Spain. As a side effect,
2283 this changes some timestamps for Africa/Ceuta before 1929, which
2284 are probably guesswork anyway. (Thanks to Steve Allen and
2285 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
2286 correcting the 1901 transition.)
2288 Ecuador observed DST from 1992-11-28 to 1993-02-05.
2289 (Thanks to Alois Treindl.)
2291 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
2292 (Thanks to Stepan Golosunov.)
2294 Changes to past and future time zone abbreviations
2296 Switch to numeric time zone abbreviations for South America, as
2297 part of the ongoing project of removing invented abbreviations.
2298 This avoids the need to invent an abbreviation for the new Chilean
2299 new zone. Similarly, switch from invented to numeric time zone
2300 abbreviations for Afghanistan, American Samoa, the Azores,
2301 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
2302 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
2303 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
2304 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
2305 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
2306 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
2307 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
2308 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
2309 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
2310 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
2311 for half-hour daylight saving time in Belize before 1944 and in
2312 the Dominican Republic before 1975; and for Canary Islands before
2313 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
2314 Indian Summer Time before 1942, for Indonesia before around 1964,
2315 for Kenya before 1960, for Liberia before 1973, for Madeira before
2316 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
2317 Pakistan before 1971, for Western Sahara before 1977, and for
2318 Zaporozhye in 1880-1924.
2320 For Alaska time from 1900 through 1967, instead of "CAT" use the
2321 abbreviation "AST", the abbreviation commonly used at the time
2322 (Atlantic Standard Time had not been standardized yet). Use "AWT"
2323 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
2325 Use "CST" and "CDT" instead of invented abbreviations for Macau
2326 before 1999 and Taiwan before 1938, and use "JST" instead of the
2327 invented abbreviation "JCST" for Japan and Korea before 1938.
2329 Change to database entry category
2331 Move the Pacific/Johnston link from 'australasia' to 'backward',
2332 since Johnston is now uninhabited.
2336 zic no longer mishandles some transitions in January 2038 when it
2337 attempts to work around Qt bug 53071. This fixes a bug affecting
2338 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
2339 now contains a workaround, useful when loading a file generated by
2340 a buggy zic. (Problem and localtime.c fix reported by Bradley
2343 zdump -i now outputs non-hour numeric time zone abbreviations
2344 without a colon, e.g., "+0530" rather than "+05:30". This agrees
2345 with zic %z and with common practice, and simplifies auditing of
2348 zdump is now buildable again with -DUSE_LTZ=0.
2349 (Problem reported by Joseph Myers.)
2351 zdump.c now always includes private.h, to avoid code duplication
2352 with private.h. (Problem reported by Kees Dekker.)
2354 localtime.c no longer mishandles early or late timestamps
2355 when TZ is set to a POSIX-style string that specifies DST.
2356 (Problem reported by Kees Dekker.)
2358 date and strftime now cause %z to generate "-0000" instead of
2359 "+0000" when the UT offset is zero and the time zone abbreviation
2362 Changes to documentation and commentary
2364 The 'Theory' file now better documents choice of historical time
2365 zone abbreviations. (Problems reported by Michael Deckers.)
2367 tz-link.htm now covers leap smearing, which is popular in clouds.
2370 Release 2016j - 2016-11-22 23:17:13 -0800
2372 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
2374 Changes to future timestamps
2376 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
2377 This hives off a new zone Europe/Saratov from Europe/Volgograd.
2378 (Thanks to Yuri Konotopov and Stepan Golosunov.)
2380 Changes to past timestamps
2382 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
2383 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
2384 1999, not fall 1994. (Thanks to Stepan Golosunov.)
2386 Changes to past time zone abbreviations
2388 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
2389 summer time before 1948. The old use of "EET" was a typo.
2393 zic no longer mishandles file systems that lack hard links, fixing
2394 bugs introduced in 2016g. (Problems reported by Tom Lane.)
2395 Also, when the destination already contains symbolic links, zic
2396 should now work better on systems where the 'link' system call
2397 does not follow symbolic links.
2399 Changes to documentation and commentary
2401 tz-link.htm now documents the relationship between release version
2402 numbers and development-repository commit tags. (Suggested by
2405 The 'Theory' file now documents UT.
2407 iso3166.tab now accents "Curaçao", and commentary now mentions
2408 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
2411 Release 2016i - 2016-11-01 23:19:52 -0700
2413 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
2414 reintroduces DST on 2016-11-06.
2416 Changes to future timestamps
2418 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
2419 2017-01-15 at 03:00. Assume future observances in Tonga will be
2420 from the first Sunday in November through the third Sunday in
2421 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
2422 time zone abbreviations for this zone.
2424 Changes to past and future timestamps
2426 Northern Cyprus is now +03 year round, causing a split in Cyprus
2427 time zones starting 2016-10-30 at 04:00. This creates a zone
2428 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
2430 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
2431 (Thanks to Steffen Thorsen.)
2433 Changes to past timestamps
2435 Several corrections were made for pre-1975 timestamps in Italy.
2436 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
2439 First, the 1893-11-01 00:00 transition in Italy used the new UT
2440 offset (+01), not the old (+00:49:56). (Thanks to Michael
2443 Second, rules for daylight saving in Italy were changed to agree
2444 with Italy's National Institute of Metrological Research (INRiM)
2445 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
2446 Inglis, and Michael Deckers):
2448 The 1916-06-03 transition was at 24:00, not 00:00.
2450 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
2453 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
2456 The 1944-09-17 transition was at 03:00, not 01:00. This
2457 particular change is taken from Italian law as INRiM's table,
2458 (which says 02:00) appears to have a typo here. Also, keep the
2459 1944-04-03 transition for Europe/Rome, as Rome was controlled by
2462 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
2467 The code should now be buildable on AmigaOS merely by setting the
2468 appropriate Makefile variables. (From a patch by Carsten Larsen.)
2471 Release 2016h - 2016-10-19 23:17:57 -0700
2473 Changes to future timestamps
2475 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2476 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
2477 future fall transitions will be on the last Saturday of October
2478 at 01:00, which is consistent with predicted spring transitions
2479 on the last Saturday of March. (Thanks to Tim Parenti.)
2481 Changes to past timestamps
2483 In Turkey, transitions in 1986-1990 were at 01:00 standard time
2484 not at 02:00, and the spring 1994 transition was on March 20, not
2485 March 27. (Thanks to Kıvanç Yazan.)
2487 Changes to past and future time zone abbreviations
2489 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
2490 instead of alphabetic ones like "IST" and "LKT". Various
2491 English-language sources use "IST", "LKT" and "SLST", with no
2492 working consensus. (Usage of "SLST" mentioned by Sadika
2497 zic no longer mishandles relativizing file names when creating
2498 symbolic links like /etc/localtime, when these symbolic links
2499 are outside the usual directory hierarchy. This fixes a bug
2500 introduced in 2016g. (Problem reported by Andreas Stieger.)
2502 Changes to build procedure
2504 New rules 'traditional_tarballs' and 'traditional_signatures' for
2505 building just the traditional-format distribution. (Requested by
2508 The file 'version' is now put into the tzdata tarball too.
2509 (Requested by Howard Hinnant.)
2511 Changes to documentation and commentary
2513 The 'Theory' file now has a section on interface stability.
2514 (Requested by Paul Koning.) It also mentions features like
2515 tm_zone and localtime_rz that have long been supported by the
2518 tz-link.htm has improved coverage of time zone boundaries suitable
2519 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
2522 The US commentary now mentions Allen and the "day of two noons".
2524 The Fiji commentary mentions the government's 2016-10-03 press
2525 release. (Thanks to Raymond Kumar.)
2528 Release 2016g - 2016-09-13 08:56:38 -0700
2530 Changes to future timestamps
2532 Turkey switched from EET/EEST (+02/+03) to permanent +03,
2533 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
2534 than an invented abbreviation for the new time.
2536 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
2537 (Thanks to Tim Parenti.)
2539 Changes to past timestamps
2541 For America/Los_Angeles, spring-forward transition times have been
2542 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2545 For zones using Soviet time on 1919-07-01, transitions to UT-based
2546 time were at 00:00 UT, not at 02:00 local time. The affected
2547 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2548 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2550 Changes to past and future time zone abbreviations
2552 The Factory zone now uses the time zone abbreviation -00 instead
2553 of a long English-language string, as -00 is now the normal way to
2554 represent an undefined time zone.
2556 Several zones in Antarctica and the former Soviet Union, along
2557 with zones intended for ships at sea that cannot use POSIX TZ
2558 strings, now use numeric time zone abbreviations instead of
2559 invented or obsolete alphanumeric abbreviations. The affected
2560 zones are Antarctica/Casey, Antarctica/Davis,
2561 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2562 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2563 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2564 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2565 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2566 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2567 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2568 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2569 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2570 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2571 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2572 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2573 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2574 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2575 was replaced by +05, whereas MSK and MSD were kept as they are not
2576 our invention and are widely used.
2578 Changes to zone names
2580 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2581 (Thanks to David Massoud.)
2585 zic no longer generates binary files containing POSIX TZ-like
2586 strings that disagree with the local time type after the last
2587 explicit transition in the data. This fixes a bug with
2588 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2589 on the reference platform. (Thanks to Alexander Belopolsky for
2590 reporting the bug and suggesting a way forward.)
2592 If the installed localtime and/or posixrules files are symbolic
2593 links, zic now keeps them symbolic links when updating them, for
2594 compatibility with platforms like OpenSUSE where other programs
2595 configure these files as symlinks.
2597 zic now avoids hard linking to symbolic links, avoids some
2598 unnecessary mkdir and stat system calls, and uses shorter file
2601 zdump has a new -i option to generate transitions in a
2602 smaller but still human-readable format. This option is
2603 experimental, and the output format may change in future versions.
2604 (Thanks to Jon Skeet for suggesting that an option was needed,
2605 and thanks to Tim Parenti and Chris Rovick for further comments.)
2607 Changes to build procedure
2609 An experimental distribution format is available, in addition
2610 to the traditional format which will continue to be distributed.
2611 The new format is a tarball tzdb-VERSION.tar.lz with signature
2612 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2613 tzdb-VERSION containing the code and data of the traditional
2614 two-tarball format, along with extra data that may be useful.
2615 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2616 for comments about the experimental format.)
2618 The release version number is now more accurate in the usual case
2619 where releases are built from a Git repository. For example, if
2620 23 commits and some working-file changes have been made since
2621 release 2016g, the version number is now something like
2622 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2623 Tagged releases use the same version number format as before,
2624 e.g., '2016g'. To support the more accurate version number, its
2625 specification has moved from a line in the Makefile to a new
2626 source file 'version'.
2628 The experimental distribution contains a file to2050.tzs that
2629 contains what should be the output of 'zdump -i -c 2050' on
2630 primary zones. If this file is available, 'make check' now checks
2631 that zdump generates this output.
2633 'make check_web' now works on Fedora-like distributions.
2635 Changes to documentation and commentary
2637 tzfile.5 now documents the new restriction on POSIX TZ-like
2638 strings that is now implemented by zic.
2640 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2641 (Thanks to Alexander Belopolsky.)
2643 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2644 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2645 description of Java 8 has been brought up to date (thanks to
2646 Stephen Colebourne). Its description of local time on Mars has
2647 been updated to match current practice, and URLs have been updated
2648 and some obsolete ones removed.
2651 Release 2016f - 2016-07-05 16:26:51 +0200
2653 Changes affecting future timestamps
2655 The Egyptian government changed its mind on short notice, and
2656 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2657 (Thanks to Mina Samuel.)
2659 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2660 (Thanks to Stepan Golosunov.)
2662 Changes to past and future timestamps
2664 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2665 abbreviations instead of invented ones.
2667 Changes affecting past timestamps
2669 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2670 (Thanks to Stepan Golosunov.)
2673 Release 2016e - 2016-06-14 08:46:16 -0700
2675 Changes affecting future timestamps
2677 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2678 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2679 For future years, guess April's last Thursday to October's last
2680 Thursday except for Ramadan.
2682 Changes affecting past timestamps
2684 Locations while uninhabited now use '-00', not 'zzz', as a
2685 placeholder time zone abbreviation. This is inspired by Internet
2686 RFC 3339 and is more consistent with numeric time zone
2687 abbreviations already used elsewhere. The change affects several
2688 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2689 1920 and Antarctica/Troll before 2005.
2691 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2692 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2696 zic now outputs a dummy transition at time 2**31 - 1 in zones
2697 whose POSIX-style TZ strings contain a '<'. This mostly works
2698 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2699 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2701 Changes affecting documentation and commentary
2703 tz-link.htm says why governments should give plenty of notice for
2704 time zone or DST changes, and refers to Matt Johnson's blog post.
2706 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2709 Release 2016d - 2016-04-17 22:50:29 -0700
2711 Changes affecting future timestamps
2713 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2714 (Thanks to Alexander Krivenyshev for the heads-up.)
2716 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2717 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2719 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2720 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2721 at 02:00. (Thanks to Stepan Golosunov.)
2723 Changes affecting past timestamps
2725 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2726 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2727 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2728 the same change. (Thanks to Stepan Golosunov.)
2730 Russia and nearby locations had daylight-saving transitions on
2731 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2732 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2735 Many corrections to historical time in Kazakhstan from 1991
2736 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2737 invented time zone abbreviations with numeric abbreviations.
2739 Changes to commentary
2741 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2744 Release 2016c - 2016-03-23 00:51:27 -0700
2746 Changes affecting future timestamps
2748 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2750 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2751 Correa for the heads-up, and to Tim Parenti for corrections.)
2752 Guess that future transitions are August's and May's second
2753 Saturdays at 24:00 mainland time. Also, call the period from
2754 2014-09-07 through 2016-05-14 daylight saving time instead of
2755 standard time, as that seems more appropriate now.
2757 Changes affecting past timestamps
2759 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2760 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2761 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2762 (Thanks to Stepan Golosunov.)
2764 Changes to commentary
2766 Several updates and URLs for historical and proposed Russian changes.
2767 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2770 Release 2016b - 2016-03-12 17:30:14 -0800
2774 Starting with release 2016b, some data entries cause zic implementations
2775 derived from tz releases 2005j through 2015e to issue warnings like
2776 "time zone abbreviation differs from POSIX standard (+03)".
2777 These warnings should not otherwise affect zic's output and can safely be
2778 ignored on today's platforms, as the warnings refer to a restriction in
2779 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2780 warnings is to upgrade to zic derived from tz releases 2015f and later.
2782 Changes affecting future timestamps
2784 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2785 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2786 2016-03-27 at 02:00 local time. They need distinct zones since their
2787 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2788 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2789 and local time. The Astrakhan change is already official; the others have
2790 passed the first reading in the State Duma and are extremely likely.
2791 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2792 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2793 and Stepan Golosunov for followup.)
2795 As a trial of a new system that needs less information to be made up,
2796 the new zones use numeric time zone abbreviations like "+04"
2797 instead of invented abbreviations like "ASTT".
2799 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2802 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2803 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2804 Saturday at 01:00, not March's last Friday at 24:00.
2806 Changes affecting past timestamps
2808 Europe/Chisinau observed DST during 1990, and switched from +04 to
2809 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2810 (Thanks to Stepan Golosunov.)
2812 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2813 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2817 tzselect's diagnostics and checking, and checktab.awk's checking,
2818 have been improved. (Thanks to J William Piggott.)
2820 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2822 tzselect now tests Julian-date TZ settings more accurately.
2823 (Thanks to J William Piggott.)
2825 Changes to commentary
2827 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2829 tzselect again limits its menu comments so that menus fit on a
2830 24×80 alphanumeric display.
2832 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2834 In the Theory file, the description of possible time zone abbreviations in
2835 tzdata has been cleaned up, as the old description was unclear and
2836 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2839 Release 2016a - 2016-01-26 23:28:02 -0800
2841 Changes affecting future timestamps
2843 America/Cayman will not observe daylight saving this year after all.
2844 Revert our guess that it would. (Thanks to Matt Johnson.)
2846 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2847 (Thanks to Alexander Krivenyshev.)
2849 Asia/Tehran now has DST predictions for the year 2038 and later,
2850 to be March 21 00:00 to September 21 00:00. This is likely better
2851 than predicting no DST, albeit off by a day every now and then.
2853 Changes affecting past and future timestamps
2855 America/Metlakatla switched from PST all year to AKST/AKDT on
2856 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2858 America/Santa_Isabel has been removed, and replaced with a
2859 backward compatibility link to America/Tijuana. Its contents were
2860 apparently based on a misreading of Mexican legislation.
2862 Changes affecting past timestamps
2864 Asia/Karachi's two transition times in 2002 were off by a minute.
2865 (Thanks to Matt Johnson.)
2867 Changes affecting build procedure
2869 An installer can now combine leap seconds with use of the backzone file,
2870 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2871 The old 'make posix_packrat' rule is now marked as obsolescent.
2872 (Thanks to Ian Abbott for an initial implementation.)
2874 Changes affecting documentation and commentary
2876 A new file LICENSE makes it easier to see that the code and data
2877 are mostly public-domain. (Thanks to James Knight.) The three
2878 non-public-domain files now use the current (3-clause) BSD license
2879 instead of older versions of that license.
2881 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2882 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2883 on editing tz source files (with a mention of Sublime zoneinfo,
2884 thanks to Gilmore Davidson).
2886 The Theory and asia files now mention the 2015 book "The Global
2887 Transformation of Time, 1870-1950", and cite a couple of reviews.
2889 The America/Chicago entry now documents the informal use of US
2890 central time in Fort Pierre, South Dakota. (Thanks to Rick
2891 McDermid, Matt Johnson, and Steve Jones.)
2894 Release 2015g - 2015-10-01 00:39:51 -0700
2896 Changes affecting future timestamps
2898 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2901 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2902 (Thanks to Alexander Krivenyshev.)
2904 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2905 (Thanks to Ken Rylander.)
2907 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2908 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2909 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2911 Changes affecting past timestamps
2913 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2915 Changes affecting code
2917 localtime no longer mishandles America/Anchorage after 2037.
2918 (Thanks to Bradley White for reporting the bug.)
2920 On hosts with signed 32-bit time_t, localtime no longer mishandles
2921 Pacific/Fiji after 2038-01-16 14:00 UTC.
2923 The localtime module allows the variables 'timezone', 'daylight',
2924 and 'altzone' to be in common storage shared with other modules,
2925 and declares them in case the system <time.h> does not.
2926 (Problems reported by Kees Dekker.)
2928 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2929 This simplifies the code and is consistent with zdump.c.
2930 (Problem reported by Christos Zoulas.)
2932 Changes affecting documentation
2934 The tzfile man page now documents that transition times denote the
2935 starts (not the ends) of the corresponding time periods.
2936 (Ambiguity reported by Bill Seymour.)
2939 Release 2015f - 2015-08-10 18:06:56 -0700
2941 Changes affecting future timestamps
2943 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2944 The abbreviation remains "KST". (Thanks to Robert Elz.)
2946 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2949 Changes affecting past and future timestamps
2951 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2952 (Thanks to Roman Tudos.)
2954 Changes affecting data format and code
2956 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2957 field of a Rule line should now be '-'; the old values 'even',
2958 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2959 Although the implementation has not changed, these features do not
2960 work in the default installation, they are not used in the data,
2961 and they are now considered obsolescent.
2963 zic now checks that two rules don't take effect at the same time.
2964 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2965 simultaneity are now documented.
2967 The two characters '%z' in a zone format now stand for the UT
2968 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2969 five hours and thirty minutes ahead. This better supports time
2970 zone abbreviations conforming to POSIX.1-2001 and later.
2972 Changes affecting installed data files
2974 Comments for America/Halifax and America/Glace_Bay have been improved.
2975 (Thanks to Brian Inglis.)
2977 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2978 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2979 installed data files for Europe/Simferopol and Europe/Tallinn.
2980 It does not affect timestamps. (Thanks to Howard Hinnant.)
2982 Changes affecting code
2984 zdump and zic no longer warn about valid time zone abbreviations
2987 Some Visual Studio 2013 warnings have been suppressed.
2988 (Thanks to Kees Dekker.)
2990 'date' no longer sets the time of day and its -a, -d, -n and -t
2991 options have been removed. Long obsolescent, the implementation
2992 of these features had porting problems. Builders no longer need
2993 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2994 (Thanks to Kees Dekker for pointing out the problem.)
2996 Changes affecting documentation
2998 The Theory file mentions naming issues earlier, as these seem to be
2999 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
3001 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
3003 Mention that Herbert Samuel introduced the term "Summer Time".
3006 Release 2015e - 2015-06-13 10:56:02 -0700
3008 Changes affecting future timestamps
3010 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
3011 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
3013 Assume Cayman Islands will observe DST starting next year, using US rules.
3014 Although it isn't guaranteed, it is the most likely.
3016 Changes affecting data format
3018 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
3019 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
3021 Changes affecting code
3023 When displaying data, tzselect converts it to the current locale's
3024 encoding if the iconv command works. (Problem reported by random832.)
3026 tzselect no longer mishandles Dominica, fixing a bug introduced
3027 in Release 2014f. (Problem reported by Owen Leibman.)
3029 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
3030 This fixes a bug introduced in Release 2014f.
3031 (Problem reported by Leonardo Chiquitto.)
3034 Release 2015d - 2015-04-24 08:09:46 -0700
3036 Changes affecting future timestamps
3038 Egypt will not observe DST in 2015 and will consider canceling it
3039 permanently. For now, assume no DST indefinitely.
3040 (Thanks to Ahmed Nazmy and Tim Parenti.)
3042 Changes affecting past timestamps
3044 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
3045 1966-07-01. Also, Yukon's time zone history is documented better.
3046 (Thanks to Brian Inglis and Dennis Ferguson.)
3048 Change affecting past and future time zone abbreviations
3050 The abbreviations for Hawaii-Aleutian standard and daylight times
3051 have been changed from HAST/HADT to HST/HDT, as per US Government
3052 Printing Office style. This affects only America/Adak since 1983,
3053 as America/Honolulu was already using the new style.
3055 Changes affecting code
3057 zic has some minor performance improvements.
3060 Release 2015c - 2015-04-11 08:55:55 -0700
3062 Changes affecting future timestamps
3064 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
3065 not 00:00 on April's last Friday. 2015's transition will therefore be on
3066 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
3067 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
3069 Changes affecting past timestamps
3071 The following changes affect some pre-1991 Chile-related timestamps
3072 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
3074 The 1910 transition was January 10, not January 1.
3076 The 1918 transition was September 10, not September 1.
3078 The UT -04 time observed from 1932 to 1942 is now considered to
3079 be standard time, not year-round DST.
3081 Santiago observed DST (UT -03) from 1946-07-15 through
3082 1946-08-31, then reverted to standard time, then switched to -05
3085 Assume transitions before 1968 were at 00:00, since we have no data
3088 The spring 1988 transition was 1988-10-09, not 1988-10-02.
3089 The fall 1990 transition was 1990-03-11, not 1990-03-18.
3091 Assume no UT offset change for Pacific/Easter on 1890-01-01,
3092 and omit all transitions on Pacific/Easter from 1942 through 1946
3093 since we have no data suggesting that they existed.
3095 One more zone has been turned into a link, as it differed
3096 from an existing zone only for older timestamps. As usual,
3097 this change affects UT offsets in pre-1970 timestamps only.
3098 The zone's old contents have been moved to the 'backzone' file.
3099 The affected zone is America/Montreal.
3101 Changes affecting commentary
3103 Mention the TZUpdater tool.
3105 Mention "The Time Now". (Thanks to Brandon Ramsey.)
3108 Release 2015b - 2015-03-19 23:28:11 -0700
3110 Changes affecting future timestamps
3112 Mongolia will start observing DST again this year, from the last
3113 Saturday in March at 02:00 to the last Saturday in September at 00:00.
3114 (Thanks to Ganbold Tsagaankhuu.)
3116 Palestine will start DST on March 28, not March 27. Also,
3117 correct the fall 2014 transition from September 26 to October 24.
3118 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
3120 Changes affecting past timestamps
3122 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
3123 regression. (Thanks to Stuart Bishop for reporting the problem.)
3125 Some more zones have been turned into links, when they differed
3126 from existing zones only for older timestamps. As usual,
3127 these changes affect UT offsets in pre-1970 timestamps only.
3128 Their old contents have been moved to the 'backzone' file.
3129 The affected zones are: America/Antigua, America/Cayman,
3130 Pacific/Midway, and Pacific/Saipan.
3132 Changes affecting time zone abbreviations
3134 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
3137 Changes affecting code
3139 Fix integer overflow bug in reference 'mktime' implementation.
3140 (Problem reported by Jörg Richter.)
3142 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
3143 to be used in the same executable as standard-library time_t functions.
3144 (Problems reported by Bradley White.)
3146 Changes affecting commentary
3148 Cite the recent Mexican decree changing Quintana Roo's time zone.
3149 (Thanks to Carlos Raúl Perasso.)
3151 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
3153 Update info about Mars time.
3156 Release 2015a - 2015-01-29 22:35:20 -0800
3158 Changes affecting future timestamps
3160 The Mexican state of Quintana Roo, represented by America/Cancun,
3161 will shift from Central Time with DST to Eastern Time without DST
3162 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
3164 Chile will not change clocks in April or thereafter; its new standard time
3165 will be its old daylight saving time. This affects America/Santiago,
3166 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
3168 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
3169 (Thanks to Tim Parenti.)
3171 Changes affecting past timestamps
3173 Iceland observed DST in 1919 and 1921, and its 1939 fallback
3174 transition was Oct. 29, not Nov. 29. Remove incorrect data from
3175 Shanks about time in Iceland between 1837 and 1908.
3177 Some more zones have been turned into links, when they differed
3178 from existing zones only for older timestamps. As usual,
3179 these changes affect UT offsets in pre-1970 timestamps only.
3180 Their old contents have been moved to the 'backzone' file.
3181 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
3184 Changes affecting code
3186 tzalloc now scrubs time zone abbreviations compatibly with the way
3187 that tzset always has, by replacing invalid bytes with '_' and by
3188 shortening too-long abbreviations.
3190 tzselect ports to POSIX awk implementations, no longer mishandles
3191 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
3192 settings to the user. (Thanks to Stefan Kuhn.)
3194 Changes affecting build procedure
3196 'make check' now checks for links to links in the data.
3197 One such link (for Africa/Asmera) has been fixed.
3198 (Thanks to Stephen Colebourne for pointing out the problem.)
3200 Changes affecting commentary
3202 The leapseconds file commentary now mentions the expiration date.
3203 (Problem reported by Martin Burnicki.)
3205 Update Mexican Library of Congress URL.
3208 Release 2014j - 2014-11-10 17:37:11 -0800
3210 Changes affecting current and future timestamps
3212 Turks & Caicos' switch from US eastern time to UT -04 year-round
3213 did not occur on 2014-11-02 at 02:00. It's currently scheduled
3214 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
3216 Changes affecting past timestamps
3218 Many pre-1989 timestamps have been corrected for Asia/Seoul and
3219 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
3220 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
3221 longer guess that Pyongyang mimicked Seoul time after World War II,
3222 as this is politically implausible.
3224 Some more zones have been turned into links, when they differed
3225 from existing zones only for older timestamps. As usual,
3226 these changes affect UT offsets in pre-1970 timestamps only.
3227 Their old contents have been moved to the 'backzone' file.
3228 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
3229 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
3230 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
3233 Changes affecting commentary
3235 The commentary is less enthusiastic about Shanks as a source,
3236 and is more careful to distinguish UT from UTC.
3239 Release 2014i - 2014-10-21 22:04:57 -0700
3241 Changes affecting future timestamps
3243 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
3244 (Thanks to Ken Rylander for the heads-up.) Guess that future
3245 years will use a similar pattern.
3247 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
3248 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
3249 (Thanks to Kiley Walbom for the heads-up.)
3251 Changes affecting time zone abbreviations
3253 Since Belarus is not changing its clocks even though Moscow is,
3254 the time zone abbreviation in Europe/Minsk is changing from FET
3255 to its more traditional value MSK on 2014-10-26 at 01:00.
3256 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
3258 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
3259 Indochina, to distinguish it better from ICT (+07).
3261 Changes affecting past timestamps
3263 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
3264 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
3265 authoritative book). Asia/Ho_Chi_Minh has been added to
3266 zone1970.tab, to give tzselect users in Vietnam two choices,
3267 since north and south Vietnam disagreed after our 1970 cutoff.
3269 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
3270 they differed from existing zones only for older timestamps. As
3271 usual, these changes affect pre-1970 timestamps only. Their old
3272 contents have been moved to the 'backzone' file.
3274 Changes affecting code
3276 The time-related library functions now set errno on failure, and
3277 some crashes in the new tzalloc-related library functions have
3278 been fixed. (Thanks to Christos Zoulas for reporting most of
3279 these problems and for suggesting fixes.)
3281 If USG_COMPAT is defined and the requested timestamp is standard time,
3282 the tz library's localtime and mktime functions now set the extern
3283 variable timezone to a value appropriate for that timestamp; and
3284 similarly for ALTZONE, daylight saving time, and the altzone variable.
3285 This change is a companion to the tzname change in 2014h, and is
3286 designed to make timezone and altzone more compatible with tzname.
3288 The tz library's functions now set errno to EOVERFLOW if they fail
3289 because the result cannot be represented. ctime and ctime_r now
3290 return NULL and set errno when a timestamp is out of range, rather
3291 than having undefined behavior.
3293 Some bugs associated with the new 2014g functions have been fixed.
3294 This includes a bug that largely incapacitated the new functions
3295 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
3296 It also includes some uses of uninitialized variables after tzalloc.
3297 The new code uses the standard type 'ssize_t', which the Makefile
3298 now gives porting advice about.
3300 Changes affecting commentary
3302 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
3305 Release 2014h - 2014-09-25 18:59:03 -0700
3307 Changes affecting past timestamps
3309 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
3311 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
3312 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
3314 Some more zones have been turned into links, when they differed
3315 from existing zones only for older timestamps. As usual,
3316 these changes affect UT offsets in pre-1970 timestamps only.
3317 Their old contents have been moved to the 'backzone' file.
3318 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
3319 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
3320 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
3322 Changes affecting code
3324 zdump -V and -v now output gmtoff= values on all platforms,
3325 not merely on platforms defining TM_GMTOFF.
3327 The tz library's localtime and mktime functions now set tzname to a value
3328 appropriate for the requested timestamp, and zdump now uses this
3329 on platforms not defining TM_ZONE, fixing a 2014g regression.
3330 (Thanks to Tim Parenti for reporting the problem.)
3332 The tz library no longer sets tzname if localtime or mktime fails.
3334 zdump -c no longer mishandles transitions near year boundaries.
3335 (Thanks to Tim Parenti for reporting the problem.)
3337 An access to uninitialized data has been fixed.
3338 (Thanks to Jörg Richter for reporting the problem.)
3340 When THREAD_SAFE is defined, the code ports to the C11 memory model.
3341 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
3342 and two threads race to initialize data used by gmtime-like functions.
3343 (Thanks to Andy Heninger for reporting the problems.)
3345 Changes affecting build procedure
3347 'make check' now checks better for properly sorted data.
3349 Changes affecting documentation and commentary
3351 zdump's gmtoff=N output is now documented, and its isdst=D output
3352 is now documented to possibly output D values other than 0 or 1.
3354 zdump -c's treatment of years is now documented to use the
3355 Gregorian calendar and Universal Time without leap seconds,
3356 and its behavior at cutoff boundaries is now documented better.
3357 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
3359 Programs are now documented to use the proleptic Gregorian calendar.
3360 (Thanks to Alan Barrett for the suggestion.)
3362 Fractional-second GMT offsets have been documented for civil time
3363 in 19th-century Chennai, Jakarta, and New York.
3366 Release 2014g - 2014-08-28 12:31:23 -0700
3368 Changes affecting future timestamps
3370 Turks & Caicos is switching from US eastern time to UT -04
3371 year-round, modeled as a switch on 2014-11-02 at 02:00.
3372 [As noted in 2014j, this switch was later delayed.]
3374 Changes affecting past timestamps
3376 Time in Russia or the USSR before 1926 or so has been corrected by
3377 a few seconds in the following zones: Asia/Irkutsk,
3378 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
3379 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
3380 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
3381 Vladimir Karpinsky.)
3383 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
3384 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
3385 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
3386 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
3387 (Thanks to Stephen Colebourne for pointing to the decree.)
3389 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
3391 A new file 'backzone' contains data which may appeal to
3392 connoisseurs of old timestamps, although it is out of scope for
3393 the tz database, is often poorly sourced, and contains some data
3394 that is known to be incorrect. The new file is not recommended
3395 for ordinary use and its entries are not installed by default.
3396 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
3397 Isle of Man entries.)
3399 Some more zones have been turned into links, when they differed
3400 from existing zones only for older timestamps. As usual,
3401 these changes affect UT offsets in pre-1970 timestamps only.
3402 Their old contents have been moved to the 'backzone' file.
3403 The affected zones are: Africa/Bangui, Africa/Brazzaville,
3404 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
3405 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
3407 Changes affecting code
3409 Unless NETBSD_INSPIRED is defined to 0, the tz library now
3410 supplies functions for creating and using objects that represent
3411 timezones. The new functions are tzalloc, tzfree, localtime_rz,
3412 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
3413 time2posix_z. They are intended for performance: for example,
3414 localtime_rz (unlike localtime_r) is trivially thread-safe without
3415 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
3416 functions, and to Alan Barrett and Jonathan Lennox for helping to
3419 zdump now builds with the tz library unless USE_LTZ is defined to 0,
3420 This lets zdump use tz features even if the system library lacks them.
3421 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
3422 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
3424 zdump now uses localtime_rz if available, as it's significantly faster,
3425 and it can help zdump better diagnose invalid timezone names.
3426 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
3427 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
3428 not available, zdump now uses localtime_r and tzset if available,
3429 as this is a bit cleaner and faster than plain localtime. Compile
3430 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
3431 lacks these two functions.
3433 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
3434 Although not needed for tz's own applications, which are single-threaded,
3435 this supports POSIX better if the tz library is used in multithreaded apps.
3437 Some crashes have been fixed when zdump or the tz library is given
3438 invalid or outlandish input.
3440 The tz library no longer mishandles leap seconds on platforms with
3441 unsigned time_t in timezones that lack ordinary transitions after 1970.
3443 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
3444 already defined, to make it easier to configure on common platforms.
3445 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
3447 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
3448 assumes that reading uninitialized memory yields garbage values
3449 but does not cause other problems such as traps.
3451 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
3452 more likely to guess right for ambiguous timestamps near
3453 transitions where tm_isdst does not change.
3455 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
3456 strftime_l for compatibility with recent versions of POSIX.
3457 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
3458 to 1 on recent POSIX versions, and to 0 otherwise.
3460 tzselect -c now uses a hybrid distance measure that works better
3461 in Africa. (Thanks to Alan Barrett for noting the problem.)
3463 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
3464 or when time_tz is defined.
3466 When HAVE_UTMPX_H is set the 'date' command now builds on systems
3467 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
3468 the date it updates the wtmpx file if _PATH_WTMPX is defined.
3469 This affects GNU/Linux and similar systems.
3471 For easier maintenance later, some C code has been simplified,
3472 some lint has been removed, and the code has been tweaked so that
3473 plain 'make' is more likely to work.
3475 The C type 'bool' is now used for boolean values, instead of 'int'.
3477 The long-obsolete LOCALE_HOME code has been removed.
3479 The long-obsolete 'gtime' function has been removed.
3481 Changes affecting build procedure
3483 'zdump' no longer links in ialloc.o, as it's not needed.
3485 'make check_time_t_alternatives' no longer assumes GNU diff.
3487 Changes affecting distribution tarballs
3489 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
3490 the tzdata tarball instead of the tzcode tarball, since they help
3491 maintain the data. The NEWS and Theory files are now also
3492 distributed in the tzdata tarball, as they're relevant for data.
3493 (Thanks to Alan Barrett for pointing this out.) Also, the
3494 leapseconds.awk file is no longer distributed in the tzcode
3495 tarball, since it belongs in the tzdata tarball (where 2014f
3496 inadvertently also distributed it).
3498 Changes affecting documentation and commentary
3500 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
3501 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
3504 The man pages have been updated to use function prototypes,
3505 to document thread-safe variants like localtime_r, and to document
3506 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
3509 The fields in Link lines have been renamed to be more descriptive
3510 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
3511 and LINK-TO has become LINK-NAME.
3513 tz-link.htm mentions the IETF's tzdist working group; Windows
3514 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
3516 Some broken URLs have been fixed in the commentary. (Thanks to
3519 Commentary about Philippines DST has been updated, and commentary
3520 on pre-1970 time in India has been added.
3523 Release 2014f - 2014-08-05 17:42:36 -0700
3525 Changes affecting future timestamps
3527 Russia will subtract an hour from most of its time zones on 2014-10-26
3528 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
3529 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
3530 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
3531 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
3532 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
3533 (Europe/Samara) are not changing their clocks. The changed zones are
3534 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
3535 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
3536 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
3537 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
3538 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
3539 but not its UTC offset. Two zones are added: Asia/Chita (split
3540 from Asia/Yakutsk, and also with two hours subtracted) and
3541 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
3542 subtracted). (Thanks to Tim Parenti for much of the above.)
3544 Changes affecting time zone abbreviations
3546 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3547 and similarly for the other Australian zones. That is, for eastern
3548 standard and daylight saving time the abbreviations are AEST and AEDT
3549 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3550 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3551 This change does not affect UT offsets, only time zone abbreviations.
3552 (Thanks to Rich Tibbett and many others.)
3554 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3555 effective 2014-10-26 at 02:00 local time.
3557 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3558 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3560 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3561 Similarly, prefer EET/EEST for eastern European time in Russia.
3563 Change time zone abbreviations in (western) Samoa to use "ST" and
3564 "DT" suffixes, as this is more likely to match common practice.
3565 Prefix "W" to (western) Samoa time when its standard-time offset
3566 disagrees with that of American Samoa.
3568 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3570 Time zone abbreviations have been updated for Japan's two time
3571 zones used 1896-1937. JWST now stands for Western Standard
3572 Time, and JCST for Central Standard Time (formerly this was CJT).
3573 These abbreviations are now used for time in Korea, Taiwan,
3574 and Sakhalin while controlled by Japan.
3576 Changes affecting past timestamps
3578 China's five zones have been simplified to two, since the post-1970
3579 differences in the other three seem to have been imaginary. The
3580 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3581 removed; backwards-compatibility links still work, albeit with
3582 different behaviors for timestamps before May 1980. Asia/Urumqi's
3583 1980 transition to UT +08 has been removed, so that it is now at
3584 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3585 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3587 Some zones have been turned into links, when they differed from existing
3588 zones only for older UT offsets where data entries were likely invented.
3589 These changes affect UT offsets in pre-1970 timestamps only. This is
3590 similar to the change in release 2013e, except this time for western
3591 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3592 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3593 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3594 Atlantic/St_Helena. This also affects the backwards-compatibility
3595 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3596 Tim Parenti, and David Patte for reporting problems in earlier
3597 versions of this change.)
3599 Asia/Shanghai's pre-standard-time UT offset has been changed from
3600 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3601 transition to standard time has been changed from 1928 to 1901.
3603 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3604 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3605 In 1946 it observed DST from 05-15 through 09-30; in 1947
3606 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3607 (Thanks to Yu-Cheng Chuang.)
3609 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3611 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3612 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3614 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3615 period from 1911 to 1950.
3617 Pacific/Chatham has been changed to New Zealand standard time plus
3618 45 minutes for the period before 1957, reflecting a 1956 remark in
3619 the New Zealand parliament.
3621 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3622 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3623 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3624 not 04-06 at 02:00; and there was no DST in 1920.
3626 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3628 Time in Russia before 1927 or so has been corrected by a few seconds in
3629 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3630 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3631 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3632 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3634 Changes affecting data format
3636 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3637 The new file's extended format allows multiple country codes per zone.
3638 The older file is still installed but is deprecated; its format is
3639 not changing and it will still be distributed for a while, but new
3640 applications should use the new file.
3642 The new file format simplifies maintenance of obscure locations.
3643 To test this, it adds coverage for the Crozet Islands and the
3644 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3646 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3647 It is still ASCII now, but commentary about the switch has been added.
3648 The new file 'zone1970.tab' already uses UTF-8.
3650 Changes affecting code
3652 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3653 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3655 'zic' no longer mishandles input when ignoring case in locales that
3656 are not compatible with English, e.g., unibyte Turkish locales when
3657 compiled with HAVE_GETTEXT.
3659 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3660 they no longer use ASCII '-' as if it were a dash.
3662 'zic' now rejects output file names that contain '.' or '..' components.
3663 (Thanks to Tim Parenti for reporting the problem.)
3665 'zic -v' now warns about output file names that do not follow
3666 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3667 David Olson for starting the ball rolling on this.)
3669 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3671 Changes affecting build procedure
3673 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3674 (Thanks to John Cochran.)
3676 Changes affecting documentation and commentary
3678 The 'Theory' file documents legacy names, the longstanding
3679 exceptions to the POSIX-inspired file name rules.
3681 The 'zic' documentation clarifies the role of time types when
3682 interpreting dates. (Thanks to Arthur David Olson.)
3684 Documentation and commentary now prefer UTF-8 to US-ASCII,
3685 allowing the use of proper accents in foreign words and names.
3686 Code and data have not changed because of this. (Thanks to
3687 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3690 Non-HTML documentation and commentary now use plain-text URLs instead of
3691 HTML insertions, and are more consistent about bracketing URLs when they
3692 are not already surrounded by white space. (Thanks to suggestions by
3695 There is new commentary about Xujiahui Observatory, the five time-zone
3696 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3697 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3698 warlord Jin Shuren in the data.
3700 Commentary about the coverage of each Russian zone has been standardized.
3701 (Thanks to Tim Parenti.)
3703 There is new commentary about contemporary timekeeping in Ethiopia.
3705 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3707 There is new commentary about time in Poland in 1919.
3709 Proper credit has been given to DST inventor George Vernon Hudson.
3711 Commentary about time in Metlakatla, AK and Resolute, NU has been
3712 improved, with a new source for the former.
3714 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3717 Commentary about permanent Antarctic bases has been updated.
3719 Several typos have been corrected. (Thanks to Tim Parenti for
3720 contributing some of these fixes.)
3722 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3723 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3724 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3725 (Thanks to a heads-up from Dirkjan Ochtman.)
3727 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3728 have been removed. These obsolescent US Naval Observatory entries were no
3729 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3732 Release 2014e - 2014-06-12 21:53:52 -0700
3734 Changes affecting near-future timestamps
3736 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3737 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3738 switch to standard time at 24:00 the last Thursday before Ramadan, and
3739 back to DST at 00:00 the first Friday after Ramadan.
3741 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3742 to Milamber Space Network.) Guess that from 2015 on Morocco will
3743 temporarily switch to standard time at 03:00 the last Saturday before
3744 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3746 Changes affecting past timestamps
3748 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3749 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3750 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3751 in 1991. (Thanks to Hank W. for reporting the problems.)
3753 Changes affecting commentary
3755 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3756 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3757 removes stale pointers to World Time Explorer and WORLDTIME.
3760 Release 2014d - 2014-05-27 21:34:40 -0700
3762 Changes affecting code
3764 zic no longer generates files containing timestamps before the Big Bang.
3765 This works around GNOME glib bug 878
3766 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3767 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3768 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3770 Changes affecting documentation
3772 tz-link.htm now mentions GNOME.
3775 Release 2014c - 2014-05-13 07:44:13 -0700
3777 Changes affecting near-future timestamps
3779 Egypt observes DST starting 2014-05-15 at 24:00.
3780 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3781 Details have not been announced, except that DST will not be observed
3782 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3783 Morocco, and that Egypt's future spring and fall transitions will be the
3784 same as 2010 when it last observed DST, namely April's last Friday at
3785 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3786 that Ramadan transitions will be at 00:00 standard time.
3788 Changes affecting code
3790 zic now generates transitions for minimum time values, eliminating guesswork
3791 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3793 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3795 Changes affecting commentary and documentation
3797 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3800 Release 2014b - 2014-03-24 21:28:50 -0700
3802 Changes affecting near-future timestamps
3804 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3805 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3807 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3808 Bengt-Inge Larsson.) This is currently an approximation; a better version
3809 will require the zic and localtime fixes mentioned below, and the plan is
3810 to wait for a while until at least the zic fixes propagate.
3812 Changes affecting code
3814 'zic' and 'localtime' no longer reject locations needing four transitions
3815 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3816 Also, 'zic' avoids some unlikely failures due to integer overflow.
3818 Changes affecting build procedure
3820 'make check' now detects Rule lines defined but never used.
3821 The NZAQ rules, an instance of this problem, have been removed.
3823 Changes affecting commentary and documentation
3825 Fix Tuesday/Thursday typo in description of time in Israel.
3826 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3828 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3829 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3830 library supports them.
3832 Add comments about Johnston Island time in the 1960s.
3833 (Thanks to Lyle McElhaney.)
3835 Morocco's 2014 DST start will be as predicted.
3836 (Thanks to Sebastien Willemijns.)
3839 Release 2014a - 2014-03-07 23:30:29 -0800
3841 Changes affecting near-future timestamps
3843 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3844 the heads-up, and to Tim Parenti for simplifying the update.)
3846 Changes affecting past timestamps
3848 Fiji ended DST on 2014-01-19 at 02:00, not the previously scheduled 03:00.
3849 (Thanks to Steffen Thorsen.)
3851 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3852 (not 1992-01-01), and observed DST during the entire next winter.
3853 (Thanks to Vladimir in Moscow via Alois Treindl.)
3855 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3856 (Thanks to Avigdor Finkelstein.)
3858 Changes affecting code
3860 A uninitialized-storage bug in 'localtime' has been fixed.
3861 (Thanks to Logan Chien.)
3863 Changes affecting the build procedure
3865 The settings for 'make check_web' now default to Ubuntu 13.10.
3867 Changes affecting commentary and documentation
3869 The boundary of the US Pacific time zone is given more accurately.
3870 (Thanks to Alan Mintz.)
3872 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3874 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3876 Better descriptions of countries with same time zone history as
3877 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3879 Several changes affect tz-link.htm, the main web page.
3881 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3884 Mention xCal (Internet RFC 6321) and jCal.
3886 Microsoft has some support for tz database names.
3888 CLDR data formats include both XML and JSON.
3890 Mention Maggiolo's map of solar vs standard time.
3891 (Thanks to Arthur David Olson.)
3893 Mention TZ4Net. (Thanks to Matt Johnson.)
3895 Mention the timezone-olson Haskell package.
3897 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3899 Remove moribund links to daylight-savings-time.info and to
3900 Simple Timer + Clocks.
3902 Update two links. (Thanks to Oscar van Vlijmen.)
3904 Fix some formatting glitches, e.g., remove random newlines from
3905 abbr elements' title attributes.
3908 Release 2013i - 2013-12-17 07:25:23 -0800
3910 Changes affecting near-future timestamps:
3912 Jordan switches back to standard time at 00:00 on December 20, 2013.
3913 The 2006-2011 transition schedule is planned to resume in 2014.
3914 (Thanks to Steffen Thorsen.)
3916 Changes affecting past timestamps:
3918 In 2004, Cuba began DST on March 28, not April 4.
3919 (Thanks to Steffen Thorsen.)
3921 Changes affecting code
3923 The compile-time flag NOSOLAR has been removed, as nowadays the
3924 benefit of slightly shrinking runtime table size is outweighed by the
3925 cost of disallowing potential future updates that exceed old limits.
3927 Changes affecting documentation and commentary
3929 The files solar87, solar88, and solar89 are no longer distributed.
3930 They were a negative experiment - that is, a demonstration that
3931 tz data can represent solar time only with some difficulty and error.
3932 Their presence in the distribution caused confusion, as Riyadh
3933 civil time was generally not solar time in those years.
3935 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3938 Release 2013h - 2013-10-25 15:32:32 -0700
3940 Changes affecting current and future timestamps:
3942 Libya has switched its UT offset back to +02 without DST, instead
3943 of +01 with DST. (Thanks to Even Scharning.)
3945 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3946 (Thanks to Gwillim Law.)
3948 Changes affecting future timestamps:
3950 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3951 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3952 (Thanks to Steffen Thorsen.)
3954 Add entries for DST transitions in Morocco in the year 2038.
3955 This avoids some year-2038 glitches introduced in 2013g.
3956 (Thanks to Yoshito Umaoka for reporting the problem.)
3958 Changes affecting API
3960 The 'tzselect' command no longer requires the 'select' command,
3961 and should now work with /bin/sh on more platforms. It also works
3962 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3963 Patrick 'P. J.' McDermott and Alan Barrett.)
3965 Changes affecting code
3967 Fix localtime overflow bugs with 32-bit unsigned time_t.
3969 zdump no longer assumes sscanf returns maximal values on overflow.
3971 Changes affecting the build procedure
3973 The builder can specify which programs to use, if any, instead of
3974 'ar' and 'ranlib', and libtz.a is now built locally before being
3975 installed. (Thanks to Michael Forney.)
3977 A dependency typo in the 'zdump' rule has been fixed.
3978 (Thanks to Andrew Paprocki.)
3980 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3981 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3983 'make clean' no longer removes 'leapseconds', since it's
3984 host-independent and is part of the distribution.
3986 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3988 Changes affecting documentation and commentary
3990 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3991 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3993 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3994 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3995 longer maintained) and for old advisories. SOFA now does C.
3997 Release 2013g - 2013-09-30 21:08:26 -0700
3999 Changes affecting current and near-future timestamps
4001 Morocco now observes DST from the last Sunday in March to the last
4002 Sunday in October, not April to September respectively. (Thanks
4003 to Steffen Thorsen.)
4005 Changes affecting 'zic'
4007 'zic' now runs on platforms that lack both hard links and symlinks.
4008 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
4009 Also, fix some bugs on platforms that lack hard links but have symlinks.
4011 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
4012 to predict the far future, fixing a bug introduced in 2013e.
4014 Changes affecting the build procedure
4016 The 'leapseconds' file is again put into the tzdata tarball.
4017 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
4018 Matt Burgess and Ian Abbott.) The timestamps of these and other
4019 dependent files in tarballs are adjusted more consistently.
4021 Changes affecting documentation and commentary
4023 The README file is now part of the data tarball as well as the code.
4024 It now states that files are public domain unless otherwise specified.
4025 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
4026 Its details about the 1989 release moved to a place of honor near
4030 Release 2013f - 2013-09-24 23:37:36 -0700
4032 Changes affecting near-future timestamps
4034 Tocantins will very likely not observe DST starting this spring.
4035 (Thanks to Steffen Thorsen.)
4037 Jordan will likely stay at UT +03 indefinitely, and will not fall
4040 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
4042 Changes affecting API
4044 The types of the global variables 'timezone' and 'altzone' (if present)
4045 have been changed back to 'long'. This is required for 'timezone'
4046 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
4047 These variables were originally 'long' in the tz code, but were
4048 mistakenly changed to 'time_t' in 1987; nobody reported the
4049 incompatibility until now. The difference matters on x32, where
4050 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
4052 Changes affecting the build procedure
4054 Avoid long strings in leapseconds.awk to work around a mawk bug.
4055 (Thanks to Cyril Baurand.)
4057 Changes affecting documentation and commentary
4059 New file 'NEWS' that contains release notes like this one.
4061 Paraguay's law does not specify DST transition time; 00:00 is customary.
4062 (Thanks to Waldemar Villamayor-Venialbo.)
4064 Minor capitalization fixes.
4066 Changes affecting version-control only
4068 The experimental GitHub repository now contains annotated and
4069 signed tags for recent releases, e.g., '2013e' for Release 2013e.
4070 Releases are tagged starting with 2012e; earlier releases were
4071 done differently, and tags would either not have a simple name or
4072 not exactly match what was released.
4074 'make set-timestamps' is now simpler and a bit more portable.
4077 Release 2013e - 2013-09-19 23:50:04 -0700
4079 Changes affecting near-future timestamps
4081 This year Fiji will start DST on October 27, not October 20.
4082 (Thanks to David Wheeler for the heads-up.) For now, guess that
4083 Fiji will continue to spring forward the Sunday before the fourth
4086 Changes affecting current and future time zone abbreviations
4088 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
4089 time zone abbreviations since 1932. (Thanks to George Ziegler,
4090 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
4091 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
4092 Asia/Makassar, and Asia/Pontianak.
4094 Use ART (UT -03, standard time), rather than WARST (also -03, but
4095 daylight saving time) for San Luis, Argentina since 2009.
4097 Changes affecting Godthåb timestamps after 2037 if version mismatch
4099 Allow POSIX-like TZ strings where the transition time's hour can
4100 range from -167 through 167, instead of the POSIX-required 0
4101 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
4102 new Fiji rules. This is a more compact way to represent
4103 far-future timestamps for America/Godthab, America/Santiago,
4104 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
4105 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
4106 this change. (Derived from a suggestion by Arthur David Olson.)
4108 Allow POSIX-like TZ strings where daylight saving time is in
4109 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
4110 Argentina Summer Time all year. This supports a more compact way
4111 to represent the 2013d data for America/Argentina/San_Luis.
4112 Because of the change for San Luis noted above this change does not
4113 affect the current data. (Thanks to Andrew Main (Zefram) for
4114 suggestions that improved this change.)
4116 Where these two TZ changes take effect, there is a minor extension
4117 to the tz file format in that it allows new values for the
4118 embedded TZ-format string, and the tz file format version number
4119 has therefore been increased from 2 to 3 as a precaution.
4120 Version-2-based client code should continue to work as before for
4121 all timestamps before 2038. Existing version-2-based client code
4122 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
4123 files, and typically works in practice even for timestamps after
4124 2037; the only known exception is America/Godthab.
4126 Changes affecting timestamps before 1970
4128 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
4129 some errors before 1947.
4131 Some zones have been turned into links, when they differ from existing
4132 zones only in older data entries that were likely invented or that
4133 differ only in LMT or transitions from LMT. These changes affect
4134 only timestamps before 1943. The affected zones are:
4135 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
4136 America/Grenada, America/Guadeloupe, America/Marigot,
4137 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
4138 America/St_Lucia, America/St_Thomas, America/St_Vincent,
4139 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
4140 confirming that the old Europe/Vaduz zone was wrong and the new
4141 link is better for WWII-era times.)
4143 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
4144 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
4147 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
4148 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
4151 Change the date of the circa-1850 Zurich transition from 1849-09-12
4152 to 1853-07-16, overriding Shanks with data from Messerli about
4153 postal and telegraph time in Switzerland.
4155 Changes affecting time zone abbreviations before 1970
4157 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
4158 as Jakarta was called Batavia back then.
4160 Changes affecting API
4162 The 'zic' command now outputs a dummy transition when far-future
4163 data can't be summarized using a TZ string, and uses a 402-year
4164 window rather than a 400-year window. For the current data, this
4165 affects only the Asia/Tehran file. It does not affect any of the
4166 timestamps that this file represents, so zdump outputs the same
4167 information as before. (Thanks to Andrew Main (Zefram).)
4169 The 'date' command has a new '-r' option, which lets you specify
4170 the integer time to display, a la FreeBSD.
4172 The 'tzselect' command has two new options '-c' and '-n', which lets you
4173 select a zone based on latitude and longitude.
4175 The 'zic' command's '-v' option now warns about constructs that
4176 require the new version-3 binary file format. (Thanks to Arthur
4177 David Olson for the suggestion.)
4179 Support for floating-point time_t has been removed.
4180 It was always dicey, and POSIX no longer requires it.
4181 (Thanks to Eric Blake for suggesting to the POSIX committee to
4182 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
4183 Heninger, Arthur David Olson, and Alois Treindl, for reporting
4184 bugs and elucidating some of the corners of the old floating-point
4187 The signatures of 'offtime', 'timeoff', and 'gtime' have been
4188 changed back to the old practice of using 'long' to represent UT
4189 offsets. This had been inadvertently and mistakenly changed to
4190 'int_fast32_t'. (Thanks to Christos Zoulas.)
4192 The code avoids undefined behavior on integer overflow in some
4193 more places, including gmtime, localtime, mktime and zdump.
4195 Changes affecting the zdump utility
4197 zdump now outputs "UT" when referring to Universal Time, not "UTC".
4198 "UTC" does not make sense for timestamps that predate the introduction
4199 of UTC, whereas "UT", a more generic term, does. (Thanks to Steve Allen
4200 for clarifying UT vs UTC.)
4202 Data changes affecting behavior of tzselect and similar programs
4204 Country code BQ is now called the more common name "Caribbean Netherlands"
4205 rather than the more official "Bonaire, St Eustatius & Saba".
4207 Remove from zone.tab the names America/Montreal, America/Shiprock,
4208 and Antarctica/South_Pole, as they are equivalent to existing
4209 same-country-code zones for post-1970 timestamps. The data entries for
4210 these names are unchanged, so the names continue to work as before.
4212 Changes affecting code internals
4214 zic -c now runs way faster on 64-bit hosts when given large numbers.
4216 zic now uses vfprintf to avoid allocating and freeing some memory.
4218 tzselect now computes the list of continents from the data,
4219 rather than have it hard-coded.
4221 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
4223 Changes affecting the build procedure
4225 The 'leapseconds' file is now generated automatically from a
4226 new file 'leap-seconds.list', which is a copy of
4227 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
4228 A new source file 'leapseconds.awk' implements this.
4229 The goal is simplification of the future maintenance of 'leapseconds'.
4231 When building the 'posix' or 'right' subdirectories, if the
4232 subdirectory would be a copy of the default subdirectory, it is
4233 now made a symbolic link if that is supported. This saves about
4234 2 MB of file system space.
4236 The links America/Shiprock and Antarctica/South_Pole have been
4237 moved to the 'backward' file. This affects only nondefault builds
4238 that omit 'backward'.
4240 Changes affecting version-control only
4242 .gitignore now ignores 'date'.
4244 Changes affecting documentation and commentary
4246 Changes to the 'tzfile' man page
4248 It now mentions that the binary file format may be extended in
4249 future versions by appending data.
4251 It now refers to the 'zdump' and 'zic' man pages.
4253 Changes to the 'zic' man page
4255 It lists conditions that elicit a warning with '-v'.
4257 It says that the behavior is unspecified when duplicate names
4258 are given, or if the source of one link is the target of another.
4260 Its examples are updated to match the latest data.
4262 The definition of white space has been clarified slightly.
4263 (Thanks to Michael Deckers.)
4265 Changes to the 'Theory' file
4267 There is a new section about the accuracy of the tz database,
4268 describing the many ways that errors can creep in, and
4269 explaining why so many of the pre-1970 timestamps are wrong or
4270 misleading (thanks to Steve Allen, Lester Caine, and Garrett
4271 Wollman for discussions that contributed to this).
4273 The 'Theory' file describes LMT better (this follows a
4274 suggestion by Guy Harris).
4276 It refers to the 2013 edition of POSIX rather than the 2004 edition.
4278 It's mentioned that excluding 'backward' should not affect the
4279 other data, and it suggests at least one zone.tab name per
4280 inhabited country (thanks to Stephen Colebourne).
4282 Some longstanding restrictions on names are documented, e.g.,
4283 'America/New_York' precludes 'America/New_York/Bronx'.
4285 It gives more reasons for the 1970 cutoff.
4287 It now mentions which time_t variants are supported, such as
4288 signed integer time_t. (Thanks to Paul Goyette for reporting
4289 typos in an experimental version of this change.)
4291 (Thanks to Philip Newton for correcting typos in these changes.)
4293 Documentation and commentary is more careful to distinguish UT in
4294 general from UTC in particular. (Thanks to Steve Allen.)
4296 Add a better source for the Zurich 1894 transition.
4297 (Thanks to Pierre-Yves Berger.)
4299 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
4302 Release 2013d - 2013-07-05 07:38:01 -0700
4304 Changes affecting future timestamps:
4306 Morocco's midsummer transitions this year are July 7 and August 10,
4307 not July 9 and August 8. (Thanks to Andrew Paprocki.)
4309 Israel now falls back on the last Sunday of October.
4310 (Thanks to Ephraim Silverberg.)
4312 Changes affecting past timestamps:
4314 Specify Jerusalem's location more precisely; this changes the pre-1880
4317 Changing affecting metadata only:
4319 Fix typos in the entries for country codes BQ and SX.
4321 Changes affecting code:
4323 Rework the code to fix a bug with handling Australia/Macquarie on
4324 32-bit hosts (thanks to Arthur David Olson).
4326 Port to platforms like NetBSD, where time_t can be wider than long.
4328 Add support for testing time_t types other than the system's.
4329 Run 'make check_time_t_alternatives' to try this out.
4330 Currently, the tests fail for unsigned time_t;
4331 this should get fixed at some point.
4333 Changes affecting documentation and commentary:
4335 Deemphasize the significance of national borders.
4337 Update the zdump man page.
4339 Remove obsolete NOID comment (thanks to Denis Excoffier).
4341 Update several URLs and comments in the web pages.
4343 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
4345 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
4348 Release 2013c - 2013-04-19 16:17:40 -0700
4350 Changes affecting current and future timestamps:
4352 Palestine observed DST starting March 29, 2013. (Thanks to
4353 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
4354 with the predicted rules being the last Thursday in March at 24:00
4355 to the first Friday on or after September 21 at 01:00.
4357 Assume that the recent change to Paraguay's DST rules is permanent,
4358 by moving the end of DST to the 4th Sunday in March every year.
4359 (Thanks to Carlos Raúl Perasso.)
4361 Changes affecting past timestamps:
4363 Fix some historical data for Palestine to agree with that of
4364 timeanddate.com, as follows:
4366 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
4369 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
4372 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
4374 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
4376 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
4378 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
4380 Fix times of habitation for Macquarie to agree with the Tasmania
4381 Parks & Wildlife Service history, which indicates that permanent
4382 habitation was 1899-1919 and 1948 on.
4384 Changing affecting metadata only:
4386 Macquarie Island is politically part of Australia, not Antarctica.
4387 (Thanks to Tobias Conradi.)
4389 Sort Macquarie more consistently with other parts of Australia.
4390 (Thanks to Tim Parenti.)
4393 Release 2013b - 2013-03-10 22:33:40 -0700
4395 Changes affecting current and future timestamps:
4397 Haiti uses US daylight-saving rules this year, and presumably future years.
4398 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
4400 Paraguay will end DST on March 24 this year.
4401 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
4403 Morocco does not observe DST during Ramadan;
4404 try to predict Ramadan in Morocco as best we can.
4405 (Thanks to Erik Homoet for the heads-up.)
4407 Changes affecting commentary:
4409 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
4410 Update URL for Solaris. Mention Internet RFC 6557.
4411 Update Internet RFCs 2445->5545, 2822->5322.
4412 Switch from FTP to HTTP for Internet RFCs.
4415 Release 2013a - 2013-02-27 09:20:35 -0800
4417 Change affecting binary data format:
4419 The zone offset at the end of version-2-format zone files is now
4420 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
4422 Changes affecting current and future timestamps:
4424 Chile's 2013 rules, and we guess rules for 2014 and later, will be
4425 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
4426 (Thanks to Steffen Thorsen and Robert Elz.)
4428 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
4429 (Thanks to Tobias Conradi and Arthur David Olson.)
4431 Many changes affect historical timestamps before 1940.
4432 These were deduced from: Milne J. Civil time. Geogr J. 1899
4433 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
4435 Changes affecting the code:
4437 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
4438 the data). (Thanks to Arthur David Olson.)
4440 Fix localtime bug when time_t is unsigned and data files were generated
4441 by a signed time_t system. (Thanks to Doug Bailey for reporting and
4442 to Arthur David Olson for fixing.)
4444 Allow the email address for bug reports to be set by the packager.
4445 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
4447 Update HTML checking to be compatible with Ubuntu 12.10.
4449 Check that files are a safe subset of ASCII. At some point we may
4450 relax this requirement to a safe subset of UTF-8. Without the
4451 check, some non-UTF-8 encodings were leaking into the distribution.
4455 Restore a comment about copyright notices that was inadvertently deleted.
4456 (Thanks to Arthur David Olson.)
4458 Improve the commentary about which districts observe what times
4459 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
4461 Add web page links to tz.js.
4463 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
4466 Release 2012j - 2012-11-12 18:34:49 -0800
4468 Libya moved to CET this weekend, but with DST planned next year.
4469 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
4471 Signatures now have the extension .asc, not .sign, as that's more
4472 standard. (Thanks to Phil Pennock.)
4474 The output of 'zdump --version', and of 'zic --version', now
4475 uses a format that is more typical for --version.
4476 (Thanks to Joseph S. Myers.)
4478 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
4479 now uses tz@iana.org rather than the old elsie address.
4481 zic -v now complains about abbreviations that are less than 3
4482 or more than 6 characters, as per POSIX. Formerly, it checked
4483 for abbreviations that were more than 3.
4485 'make public' no longer puts its temporary directory under /tmp,
4486 and uses the just-built zic rather than the system zic.
4488 Various fixes to documentation and commentary.
4491 Release 2012i - 2012-11-03 12:57:09 -0700
4493 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
4495 Linker flags can now be specified via LDFLAGS.
4496 AWK now defaults to 'awk', not 'nawk'.
4497 The shell in tzselect now defaults to /bin/bash, but this can
4498 be overridden by specifying KSHELL.
4499 The main web page now mentions the unofficial GitHub repository.
4500 (Thanks to Mike Frysinger.)
4502 Tarball signatures can now be built by running 'make signatures'.
4503 There are also new makefile rules 'tarballs', 'check_public', and
4504 separate makefile rules for each tarball and signature file.
4505 A few makefile rules are now more portable to strict POSIX.
4507 The main web page now lists the canonical IANA URL.
4510 Release 2012h - 2012-10-26 22:49:10 -0700
4512 Bahia no longer has DST. (Thanks to Kelley Cook.)
4514 Tocantins has DST. (Thanks to Rodrigo Severo.)
4516 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
4518 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
4522 More C modernization, except that at Arthur David Olson's suggestion
4523 the instances of 'register' were kept.
4526 Release 2012g - 2012-10-17 20:59:45 -0700
4528 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
4530 Palestine fall 2012. (Thanks to Steffen Thorsen.)
4534 To attack the version-number problem, this release ships the file
4535 'Makefile' (which contains the release number) in both the tzcode and
4536 the tzdata tarballs. The two Makefiles are identical, and should be
4537 identical in any matching pair of tarballs, so it shouldn't matter
4538 which order you extract the tarballs. Perhaps we can come up with a
4539 better version-number scheme at some point; this scheme does have the
4540 virtue of not adding more files.
4543 Release 2012f - 2012-09-12 23:17:03 -0700
4545 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4546 20 this year. (Thanks to Steffen Thorsen.)
4549 Release 2012e - 2012-08-02 20:44:55 -0700
4551 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4552 (Thanks to Steffen Thorsen.)
4554 * Use a single version number for both code and data.
4556 * .gitignore: New file.
4558 * Remove trailing white space.
4561 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4563 Changes for Morocco's timestamps, which take effect in a couple of
4564 hours, along with infrastructure changes to accommodate how the tz
4565 code and data are released on IANA.
4568 Release data2012c - 2012-03-27 12:17:25 -0400
4571 Summer time changes for Morocco (to start late April 2012)
4574 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4577 Haiti following US/Canada rules for 2012 (and we're assuming,
4578 for now anyway, for the future).
4581 Release 2012b - 2012-03-02 12:29:15 +0700
4583 There is just one change to tzcode2012b (compared with 2012a):
4584 the Makefile that was accidentally included with 2012a has been
4585 replaced with the version that should have been there, which is
4586 identical with the previous version (from tzcode2011i).
4588 There are just two changes in tzdata2012b compared with 2012a.
4590 Most significantly, summer time in Cuba has been delayed 3 weeks
4591 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4592 date, as listed in 2012a) is just a little over a week away, this
4595 Less importantly, an excess tab in one of the changes in zone.tab
4596 in 2012a has been removed.
4599 Release 2012a - 2012-03-01 18:28:10 +0700
4601 The changes in tzcode2012a (compared to the previous version, 2011i)
4602 are entirely to the README and tz-art.htm and tz-link.htm files, if
4603 none of those concern you, you can ignore the code update. The changes
4604 reflect the changed addresses for the mailing list and the code and
4605 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4606 has been added to tz-link.htm).
4608 In tzdata2012a (compared to the previous release, which was 2011n)
4609 the major changes are:
4610 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4611 Falkland Islands onto permanent summer time (we're assuming for the
4612 foreseeable future, though 2012 is all we're fairly certain of.)
4613 Armenia has abolished Summer Time.
4614 Tokelau jumped the International Date Line back last December
4615 (just the same as their near neighbour, Samoa).
4616 America/Creston is a new zone for a small area of British Columbia
4617 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4619 Other minor changes are:
4620 Corrections to 1918 Canadian summer time end dates.
4621 Updated URL for UK time zone history (in comments)
4622 A few typos in Le Corre's list of free French place names (comments)
4625 Release data2011n - 2011-10-30 14:57:54 +0700
4627 There are three changes of note - most urgently, Cuba (America/Havana)
4628 has extended summer time by two weeks, now to end on Nov 13, rather than
4629 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4630 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4631 all, and consequently that zone has been removed (again) and reinstated
4632 in the "backward" file as a link to Europe/Chisinau. And third, the
4633 end date for Fiji's summer time this summer was moved forward from the
4634 earlier planned Feb 26, to Jan 22.
4636 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4637 (and the incorrect syntax that was in the 2011m version of that file
4638 is so fixed - it would have been fixed in a different way had this
4639 change not happened - that's the "missing" sccs version id).
4642 Release data2011m - 2011-10-24 21:42:16 +0700
4644 In particular, the typos in comments in the data (2011-11-17 should have
4645 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4646 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4647 made in all 4 Ukrainian zones, rather than just Europe/Kiev
4648 (again, thanks to Tim Parenti, and also Denys Gavrysh).
4650 In addition, I added Europe/Tiraspol to zone.tab.
4652 This time, all the files have new version numbers... (including the files
4653 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4654 version numbers there...)
4657 Release data2011l - 2011-10-10 11:15:43 +0700
4659 There are just 2 changes that cause different generated tzdata files from
4660 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4661 is included, but commented out. Compared with the diff I sent out last week,
4662 this version also includes attributions for the sources for the changes
4663 (in much the same format as ado used, but the html tags have not been
4664 checked, verified, or used in any way at all, so if there are errors there,
4665 please let me know.)
4668 Release data2011k - 2011-09-20 17:54:03 -0400
4673 Release data2011j - 2011-09-12 09:22:49 -0400
4675 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4676 Tanzania); there are also two spelling corrections to comments in
4677 the australasia file (with thanks to Christos Zoulas).
4680 Release 2011i - 2011-08-29 05:56:32 -0400
4685 Release data2011h - 2011-06-15 18:41:48 -0400
4687 Russia and Curaçao changes
4690 Release 2011g - 2011-04-25 09:07:22 -0400
4692 update the rules for Egypt to reflect its abandonment of DST this year
4695 Release 2011f - 2011-04-06 17:14:53 -0400
4700 Release 2011e - 2011-03-31 16:04:38 -0400
4702 Morocco, Chile, and tz-link changes
4705 Release 2011d - 2011-03-14 09:18:01 -0400
4707 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4710 Release 2011c - 2011-03-07 09:30:09 -0500
4712 These do affect current timestamps in Chile and Annette Island, Canada.
4715 Release 2011b - 2011-02-07 08:44:50 -0500
4720 Release 2011a - 2011-01-24 10:30:16 -0500
4725 Release data2010o - 2010-11-01 09:18:23 -0400
4727 change to the end of DST in Fiji in 2011
4730 Release 2010n - 2010-10-25 08:19:17 -0400
4735 Release 2010m - 2010-09-27 09:24:48 -0400
4737 Hong Kong, Vostok, and zic.c changes
4740 Release 2010l - 2010-08-16 06:57:25 -0400
4745 Release 2010k - 2010-07-26 10:42:27 -0400
4750 Release 2010j - 2010-05-10 09:07:48 -0400
4752 changes for Bahía de Banderas and for version naming
4755 Release data2010i - 2010-04-16 18:50:45 -0400
4757 the end of DST in Morocco on 2010-08-08
4760 Release data2010h - 2010-04-05 09:58:56 -0400
4765 Release data2010g - 2010-03-24 11:14:53 -0400
4770 Release 2010f - 2010-03-22 09:45:46 -0400
4775 Release data2010e - 2010-03-08 14:24:27 -0500
4777 corrects the Dhaka bug found by Danvin Ruangchan
4780 Release data2010d - 2010-03-06 07:26:01 -0500
4785 Release 2010c - 2010-03-01 09:20:58 -0500
4787 changes including KRE's suggestion for earlier initialization of
4788 "goahead" and "goback" structure elements
4791 Release code2010a - 2010-02-16 10:40:04 -0500
4796 Release data2010b - 2010-01-20 12:37:01 -0500
4801 Release data2010a - 2010-01-18 08:30:04 -0500
4806 Release data2009u - 2009-12-26 08:32:28 -0500
4808 changes to DST in Bangladesh
4811 Release 2009t - 2009-12-21 13:24:27 -0500
4816 Release data2009s - 2009-11-14 10:26:32 -0500
4818 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4821 Release 2009r - 2009-11-09 10:10:31 -0500
4823 "antarctica" and "tz-link.htm" changes
4826 Release 2009q - 2009-11-02 09:12:40 -0500
4828 with two corrections as reported by Eric Muller and Philip Newton
4831 Release data2009p - 2009-10-23 15:05:27 -0400
4833 Argentina (including San Luis) changes (with the correction from
4837 Release data2009o - 2009-10-14 16:49:38 -0400
4839 Samoa (commentary only), Pakistan, and Bangladesh changes
4842 Release data2009n - 2009-09-22 15:13:38 -0400
4844 added commentary for Argentina and a change to the end of DST in
4848 Release data2009m - 2009-09-03 10:23:43 -0400
4850 Samoa and Palestine changes
4853 Release data2009l - 2009-08-14 09:13:07 -0400
4855 Samoa (comments only) and Egypt
4858 Release 2009k - 2009-07-20 09:46:08 -0400
4863 Release data2009j - 2009-06-15 06:43:59 -0400
4865 Bangladesh change (with a short turnaround since the DST change is
4869 Release 2009i - 2009-06-08 09:21:22 -0400
4871 updating for DST in Bangladesh this year
4874 Release 2009h - 2009-05-26 09:19:14 -0400
4879 Release data2009g - 2009-04-20 16:34:07 -0400
4884 Release data2009f - 2009-04-10 11:00:52 -0400
4886 correct DST in Pakistan
4889 Release 2009e - 2009-04-06 09:08:11 -0400
4894 Release 2009d - 2009-03-23 09:38:12 -0400
4896 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4899 Release data2009c - 2009-03-16 09:47:51 -0400
4901 change to the start of Cuban DST
4904 Release 2009b - 2009-02-09 11:15:22 -0500
4909 Release 2009a - 2009-01-21 10:09:39 -0500
4914 Release data2008i - 2008-10-21 12:10:25 -0400
4916 southamerica and zone.tab files, with Argentina DST rule changes and
4917 United States zone reordering and recommenting
4920 Release 2008h - 2008-10-13 07:33:56 -0400
4925 Release 2008g - 2008-10-06 09:03:18 -0400
4927 Fix a broken HTML anchor and update Brazil's DST transitions;
4928 there's also a slight reordering of information in tz-art.htm.
4931 Release data2008f - 2008-09-09 22:33:26 -0400
4936 Release 2008e - 2008-07-28 14:11:17 -0400
4938 changes by Arthur David Olson and Jesper Nørgaard Welen
4941 Release data2008d - 2008-07-07 09:51:38 -0400
4943 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4946 Release data2008c - 2008-05-19 17:48:03 -0400
4948 Pakistan, Morocco, and Mongolia
4951 Release data2008b - 2008-03-24 08:30:59 -0400
4953 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4957 Release 2008a - 2008-03-08 05:42:16 -0500
4962 Release 2007k - 2007-12-31 10:25:22 -0500
4964 most importantly, changes to the "southamerica" file based on
4965 Argentina's readoption of daylight saving time
4968 Release 2007j - 2007-12-03 09:51:01 -0500
4970 1. eliminate the "P" (parameter) macro;
4972 2. the "noncontroversial" changes circulated on the time zone
4973 mailing list (less the changes to "logwtmp.c");
4975 3. eliminate "too many transition" errors when "min" is used in time
4978 4. changes by Paul Eggert (including updated information for Venezuela).
4981 Release data2007i - 2007-10-30 10:28:11 -0400
4983 changes for Cuba and Syria
4986 Release 2007h - 2007-10-01 10:05:51 -0400
4988 changes by Paul Eggert, as well as an updated link to the ICU
4989 project in tz-link.htm
4992 Release 2007g - 2007-08-20 10:47:59 -0400
4994 changes by Paul Eggert
4996 The "leapseconds" file has been updated to incorporate the most
4997 recent International Earth Rotation and Reference Systems Service
5000 There's an addition to tz-art.htm regarding the television show "Medium".
5003 Release 2007f - 2007-05-07 10:46:46 -0400
5005 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
5008 changes to zic.c to allow hour values greater than 24 (along with
5009 Paul's improved time value overflow checking)
5012 Release 2007e - 2007-04-02 10:11:52 -0400
5014 Syria and Honduras changes by Paul Eggert
5016 zic.c variable renaming changes by Arthur David Olson
5019 Release 2007d - 2007-03-20 08:48:30 -0400
5021 changes by Paul Eggert
5023 the elimination of white space at the ends of lines
5026 Release 2007c - 2007-02-26 09:09:37 -0500
5028 changes by Paul Eggert
5031 Release 2007b - 2007-02-12 09:34:20 -0500
5033 Paul Eggert's proposed change to the quotation handling logic in zic.c.
5035 changes to the commentary in "leapseconds" reflecting the IERS
5036 announcement that there is to be no positive leap second at the end
5040 Release 2007a - 2007-01-08 12:28:29 -0500
5042 changes by Paul Eggert
5044 Derick Rethans's Asmara change
5046 Oscar van Vlijmen's Easter Island local mean time change
5048 symbolic link changes
5051 Release 2006p - 2006-11-27 08:54:27 -0500
5053 changes by Paul Eggert
5056 Release 2006o - 2006-11-06 09:18:07 -0500
5058 changes by Paul Eggert
5061 Release 2006n - 2006-10-10 11:32:06 -0400
5063 changes by Paul Eggert
5066 Release 2006m - 2006-10-02 15:32:35 -0400
5068 changes for Uruguay, Palestine, and Egypt by Paul Eggert
5070 (minimalist) changes to zic.8 to clarify "until" information
5073 Release data2006l - 2006-09-18 12:58:11 -0400
5075 Paul's best-effort work on this coming weekend's Egypt time change
5078 Release 2006k - 2006-08-28 12:19:09 -0400
5080 changes by Paul Eggert
5083 Release 2006j - 2006-08-21 09:56:32 -0400
5085 changes by Paul Eggert
5088 Release code2006i - 2006-08-07 12:30:55 -0400
5092 Ken Pizzini's conversion script
5095 Release code2006h - 2006-07-24 09:19:37 -0400
5097 adds public domain notices to four files
5099 includes a fix for transition times being off by a second
5101 adds a new recording to the "arts" file (information courtesy Colin Bowern)
5104 Release 2006g - 2006-05-08 17:18:09 -0400
5106 northamerica changes by Paul Eggert
5109 Release 2006f - 2006-05-01 11:46:00 -0400
5111 a missing version number problem is fixed (with thanks to Bradley
5112 White for catching the problem)
5115 Release 2006d - 2006-04-17 14:33:43 -0400
5117 changes by Paul Eggert
5119 added new items to tz-arts.htm that were found by Paul
5122 Release 2006c - 2006-04-03 10:09:32 -0400
5124 two sets of data changes by Paul Eggert
5126 a fencepost error fix in zic.c
5128 changes to zic.c and the "europe" file to minimize differences
5129 between output produced by the old 32-bit zic and the new 64-bit
5133 Release 2006b - 2006-02-20 10:08:18 -0500
5134 [tz32code2006b + tz64code2006b + tzdata2006b]
5138 All SCCS IDs were bumped to "8.1" for this release.
5141 Release 2006a - 2006-01-30 08:59:31 -0500
5143 changes by Paul Eggert (in particular, Indiana time zone moves)
5145 an addition to the zic manual page to describe how special-case
5146 transitions are handled
5149 Release 2005r - 2005-12-27 09:27:13 -0500
5151 Canadian changes by Paul Eggert
5153 They also add "<pre>" directives to time zone data files and reflect
5154 changes to warning message logic in "zdump.c" (but with calls to
5155 "gettext" kept unbundled at the suggestion of Ken Pizzini).
5158 Release 2005q - 2005-12-13 09:17:09 -0500
5160 Nothing earth-shaking here:
5161 1. Electronic mail addresses have been removed.
5162 2. Casts of the return value of exit have been removed.
5163 3. Casts of the argument of is.* macros have been added.
5164 4. Indentation in one section of zic.c has been fixed.
5165 5. References to dead URLs in the data files have been dealt with.
5168 Release 2005p - 2005-12-05 10:30:53 -0500
5170 "systemv", "tz-link.htm", and "zdump.c" changes
5171 (less the casts of arguments to the is* macros)
5174 Release 2005o - 2005-11-28 10:55:26 -0500
5176 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
5178 zdump.c lint fixes by Arthur David Olson
5181 Release 2005n - 2005-10-03 09:44:09 -0400
5183 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
5187 Release 2005m - 2005-08-29 12:15:40 -0400
5189 changes by Paul Eggert (with a small tweak to the tz-art change)
5191 a declaration of an unused variable has been removed from zdump.c
5194 Release 2005l - 2005-08-22 12:06:39 -0400
5196 changes by Paul Eggert
5198 overflow/underflow checks by Arthur David Olson, minus changes to
5199 the "Theory" file about the pending addition of 64-bit data (I grow
5200 less confident of the changes being accepted with each passing day,
5201 and the changes no longer increase the data files nine-fold--there's
5202 less than a doubling in size by my local Sun's reckoning)
5205 Release 2005k - 2005-07-14 14:14:24 -0400
5207 The "leapseconds" file has been edited to reflect the recently
5208 announced leap second at the end of 2005.
5210 I've also deleted electronic mail addresses from the files as an
5214 Release 2005j - 2005-06-13 14:34:13 -0400
5216 These reflect changes to limit the length of time zone abbreviations
5217 and the characters used in those abbreviations.
5219 There are also changes to handle POSIX-style "quoted" timezone
5220 environment variables.
5222 The changes were circulated on the time zone mailing list; the only
5223 change since then was the removal of a couple of minimum-length of
5224 abbreviation checks.
5227 Release data2005i - 2005-04-21 15:04:16 -0400
5229 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
5232 Release 2005h - 2005-04-04 11:24:47 -0400
5234 changes by Paul Eggert
5236 minor changes to Makefile and zdump.c to produce more useful output
5237 when doing a "make typecheck"
5240 Release 2005g - 2005-03-14 10:11:21 -0500
5242 changes by Paul Eggert (a change to current DST rules in Uruguay and
5243 an update to a link to time zone software)
5246 Release 2005f - 2005-03-01 08:45:32 -0500
5248 data and documentation changes by Paul Eggert
5251 Release 2005e - 2005-02-10 15:59:44 -0500
5256 Release code2005d - 2005-01-31 09:21:47 -0500
5258 make zic complain about links to links if the -v flag is used
5260 have "make public" do more code checking
5262 add an include to "localtime.c" for the benefit of gcc systems
5265 Release 2005c - 2005-01-17 18:36:29 -0500
5267 get better results when mktime runs on a system where time_t is double
5269 changes to the data files (most importantly to Paraguay)
5272 Release 2005b - 2005-01-10 09:19:54 -0500
5274 Get localtime and gmtime working on systems with exotic time_t types.
5276 Update the leap second commentary in the "leapseconds" file.
5279 Release 2005a - 2005-01-01 13:13:44 -0500
5284 Release code2004i - 2004-12-14 13:42:58 -0500
5286 Deal with systems where time_t is unsigned.
5289 Release code2004h - 2004-12-07 11:40:18 -0500
5291 64-bit-time_t changes
5294 Release 2004g - 2004-11-02 09:06:01 -0500
5296 update to Cuba (taking effect this weekend)
5298 other changes by Paul Eggert
5300 correction of the spelling of Oslo
5302 changed versions of difftime.c and private.h
5305 Release code2004f - 2004-10-21 10:25:22 -0400
5307 Cope with wide-ranging tm_year values.
5310 Release 2004e - 2004-10-11 14:47:21 -0400
5312 Brazil/Argentina/Israel changes by Paul Eggert
5314 changes to tz-link.htm by Paul
5316 one small fix to Makefile
5319 Release 2004d - 2004-09-22 08:27:29 -0400
5321 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
5324 Release 2004c - 2004-08-11 12:06:26 -0400
5326 asctime-related changes
5328 (variants of) some of the documentation changes suggested by Paul Eggert
5331 Release 2004b - 2004-07-19 14:33:35 -0400
5333 data changes by Paul Eggert - most importantly, updates for Argentina
5336 Release 2004a - 2004-05-27 12:00:47 -0400
5338 changes by Paul Eggert
5340 Handle DST transitions that occur at the end of a month in some
5341 years but at the start of the following month in other years.
5343 Add a copy of the correspondence that's the basis for claims about
5344 DST in the Navajo Nation.
5347 Release 2003e - 2003-12-15 09:36:47 -0500
5349 changes by Arthur David Olson (primarily code changes)
5351 changes by Paul Eggert (primarily data changes)
5353 minor changes to "Makefile" and "northamerica" (in the latter case,
5354 optimization of the "Toronto" rules)
5357 Release 2003d - 2003-10-06 09:34:44 -0400
5359 changes by Paul Eggert
5362 Release 2003c - 2003-09-16 10:47:05 -0400
5364 Fix bad returns in zic.c's inleap function.
5365 Thanks to Bradley White for catching the problem!
5368 Release 2003b - 2003-09-16 07:13:44 -0400
5370 Add a "--version" option (and documentation) to the zic and zdump commands.
5372 changes to overflow/underflow checking in zic
5374 a localtime typo fix.
5376 Update the leapseconds and tz-art.htm files.
5379 Release 2003a - 2003-03-24 09:30:54 -0500
5381 changes by Paul Eggert
5383 a few additions and modifications to the tz-art.htm file
5386 Release 2002d - 2002-10-15 13:12:42 -0400
5388 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
5390 There's also a new time zone quote in "tz-art.htm".
5393 Release 2002c - 2002-04-04 11:55:20 -0500
5395 changes by Paul Eggert
5397 Change zic.c to avoid creating symlinks to files that don't exist.
5400 Release 2002b - 2002-01-28 12:56:03 -0500
5402 [These change notes are for Release 2002a, which was corrupted.
5403 2002b was a corrected version of 2002a.]
5405 changes by Paul Eggert
5407 Update the "leapseconds" file to note that there'll be no leap
5408 second at the end of June, 2002.
5410 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
5412 Change to "difftime.c" to avoid sizeof problems.
5415 Release 2001d - 2001-10-09 13:31:32 -0400
5417 changes by Paul Eggert
5420 Release 2001c - 2001-06-05 13:59:55 -0400
5422 changes by Paul Eggert and Andrew Brown
5425 Release 2001b - 2001-04-05 16:44:38 -0400
5427 changes by Paul Eggert (modulo jnorgard's typo fix)
5429 tz-art.htm has been HTMLified.
5432 Release 2001a - 2001-03-13 12:57:44 -0500
5434 changes by Paul Eggert
5436 An addition to the "leapseconds" file: comments with the text of the
5437 latest IERS leap second notice.
5439 Trailing white space has been removed from data file lines, and
5440 repeated spaces in "Rule Jordan" lines in the "asia" file have been
5444 Release 2000h - 2000-12-14 15:33:38 -0500
5446 changes by Paul Eggert
5448 one typo fix in the "art" file
5450 With providence, this is the last update of the millennium.
5453 Release 2000g - 2000-10-10 11:35:22 -0400
5455 changes by Paul Eggert
5457 correction of John Mackin's name submitted by Robert Elz
5459 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
5460 Emmy Awards broadcast.
5463 Release 2000f - 2000-08-10 09:31:58 -0400
5465 changes by Paul Eggert
5467 Added information in "tz-art.htm" on a Seinfeld reference to DST.
5469 Error checking and messages in the "yearistype" script have been
5473 Release 2000e - 2000-07-31 09:27:54 -0400
5475 data changes by Paul Eggert
5477 a change to the default value of the defined constant HAVE_STRERROR
5479 the addition of a Dave Barry quote on DST to the tz-arts file
5482 Release 2000d - 2000-04-20 15:43:04 -0400
5484 changes to the documentation and code of strftime for C99 conformance
5486 a bug fix for date.c
5488 These are based on (though modified from) changes by Paul Eggert.
5491 Release 2000c - 2000-03-04 10:31:43 -0500
5493 changes by Paul Eggert
5496 Release 2000b - 2000-02-21 12:16:29 -0500
5498 changes by Paul Eggert and Joseph Myers
5500 modest tweaks to the tz-art.htm and tz-link.htm files
5503 Release 2000a - 2000-01-18 09:21:26 -0500
5505 changes by Paul Eggert
5507 The two hypertext documents have also been renamed.
5510 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
5512 Paul Eggert's changes
5514 additions to the "zic" manual page and the "Arts.htm" file
5517 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
5522 Release data1999h - 1999-10-07 03:50:29 -0400
5524 changes by Paul Eggert to "europe" (most importantly, fixing
5525 Lithuania and Estonia)
5528 Release 1999g - 1999-09-28 11:06:18 -0400
5530 data changes by Paul Eggert (most importantly, the change for
5531 Lebanon that buys correctness for this coming Sunday)
5533 The "code" file contains changes to "Makefile" and "checktab.awk" to
5534 allow better checking of time zone files before they are published.
5537 Release 1999f - 1999-09-23 09:48:14 -0400
5539 changes by Arthur David Olson and Paul Eggert
5542 Release 1999e - 1999-08-17 15:20:54 -0400
5544 changes circulated by Paul Eggert, although the change to handling
5545 of DST-specifying timezone names has been commented out for now
5546 (search for "XXX" in "localtime.c" for details). These files also
5547 do not make any changes to the start of DST in Brazil.
5549 In addition to Paul's changes, there are updates to "Arts.htm" and
5553 Release 1999d - 1999-03-30 11:31:07 -0500
5555 changes by Paul Eggert
5557 The Makefile's "make public" rule has also been changed to do a test
5558 compile of each individual time zone data file (which should help
5559 avoid problems such as the one we had with Nicosia).
5562 Release 1999c - 1999-03-25 09:47:47 -0500
5564 changes by Paul Eggert, most importantly the change for Chile.
5567 Release 1999b - 1999-02-01 17:51:44 -0500
5569 changes by Paul Eggert
5571 code changes (suggested by Mani Varadarajan, mani at be.com) for
5572 correct handling of symbolic links when building using a relative directory
5574 code changes to generate correct messages for failed links
5576 updates to the URLs in Arts.htm
5579 Release 1999a - 1999-01-19 16:20:29 -0500
5581 error message internationalizations and corrections in zic.c and
5582 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5586 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5588 changes for Brazil, Chile, and Germany
5590 support for use of "24:00" in the input files for the time zone compiler
5593 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5595 changes by Paul Eggert
5597 correction to a define in the "private.h" file
5600 Release data1998g - 1998-08-11 03:28:35 -0000
5601 [tzdata1998g.tar.gz is missing!]
5603 Lithuanian change provided by mgedmin at pub.osf.it
5605 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5606 "backward") to ensure that the GMT file is created even where folks
5607 don't want the "backward" links (as suggested by Paul Eggert).
5610 Release data1998f - 1998-07-20 13:50:00 -0000
5611 [tzdata1998f.tar.gz is missing!]
5613 Update the "leapseconds" file to include the newly announced
5614 insertion at the end of 1998.
5617 Release code1998f - 1998-06-01 10:18:31 -0400
5619 addition to localtime.c by Guy Harris
5622 Release 1998e - 1998-05-28 09:56:26 -0400
5624 The Makefile is changed to produce zoneinfo-posix rather than
5625 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5628 data changes by Paul Eggert
5630 changes from Guy Harris to provide asctime_r and ctime_r
5632 A usno1998 file (substantially identical to usno1997) has been added.
5635 Release 1998d - 1998-05-14 11:58:34 -0400
5637 changes to comments (in particular, elimination of references to CIA maps).
5638 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5639 where changes occur.
5642 Release 1998c - 1998-02-28 12:32:26 -0500
5644 changes by Paul Eggert (save the "French correction," on which I'll
5645 wait for the dust to settle)
5649 changes and additions to Arts.htm
5652 Release 1998b - 1998-01-17 14:31:51 -0500
5654 URL cleanups and additions
5657 Release 1998a - 1998-01-13 12:37:35 -0500
5659 changes by Paul Eggert
5662 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5664 changes by Paul Eggert, with minor modifications from Arthur David
5665 Olson to make the files more browser friendly
5668 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5670 minor changes to put "TZif" at the start of each timezone information file
5672 a rule has also been added to the Makefile so you can
5674 to just recompile the zone information files (rather than doing a
5675 full "make install" with its other effects).
5678 Release data1997i - 1997-10-07 08:45:38 -0400
5680 changes to Africa by Paul Eggert
5683 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5685 corrections for Uruguay (and other locations)
5687 Arthur David Olson's simple-minded fix allowing mktime to both
5688 correctly handle leap seconds and correctly handle tm_sec values
5689 upon which arithmetic has been performed.
5692 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5694 Paul Eggert's updates
5696 a small change to a function prototype;
5698 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5699 include information on Around the World in Eighty Days.
5702 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5704 fixes to zic's error handling
5706 changes inspired by the item circulated on Slovenia
5708 The description of Web resources has been HTMLified for browsing
5711 A new piece of tz-related music has been added to the "Music" file.
5714 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5716 Paul Eggert's latest suggestions
5719 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5721 changes to "zic.c" to correct performance of the "-s" option
5723 a new file "usno1997"
5726 Release data1997c - 1997-03-04 09:58:18 -0500
5731 Release 1997b - 1997-02-27 18:34:19 -0500
5733 The data file incorporates the 1997 leap second.
5735 The code file incorporates Arthur David Olson's take on the
5736 zic/multiprocessor/directory-creation situation.
5739 Release 1997a - 1997-01-21 09:11:10 -0500
5741 Paul Eggert's Antarctica (and other changes)
5743 Arthur David Olson finessed the "getopt" issue by checking against
5744 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5745 is returned while SunOS 5.5's manual says EOF is returned).
5748 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5750 Paul Eggert's latest changes
5753 Release code1996n - 1996-12-16 09:42:02 -0500
5755 link snapping fix from Bruce Evans (via Garrett Wollman)
5758 Release data1996m - 1996-11-24 02:37:34 -0000
5759 [tzdata1996m.tar.gz is missing!]
5761 Paul Eggert's batch of changes
5764 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5766 No functional changes here; the files have simply been changed to
5767 make more use of ISO style dates in comments. The names of the above
5768 files now include the year in full.
5771 Release code96l - 1996-09-08 17:12:20 -0400
5773 tzcode96k was missing a couple of pieces.
5776 Release 96k - 1996-09-08 16:06:22 -0400
5778 the latest round of changes from Paul Eggert
5780 the recent Year 2000 material
5783 Release code96j - 1996-07-30 13:18:53 -0400
5785 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5788 Release code96i - 1996-07-27 20:11:35 -0400
5790 Paul's suggested patch for strftime %V week numbers
5793 Release data96i - 1996-07-01 18:13:04 -0400
5795 "northamerica" and "europe" changes by Paul Eggert
5798 Release code96h - 1996-06-05 08:02:21 -0400
5800 fix for handling transitions specified in Universal Time
5802 Some "public domain" notices have also been added.
5805 Release code96g - 1996-05-16 14:00:26 -0400
5807 fix for the simultaneous-DST-and-zone-change challenge
5810 Release data96h - 1996-05-09 17:40:51 -0400
5812 changes by Paul Eggert
5815 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5816 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5818 The changes get us some of the way to fixing the problems noted in Paul
5819 Eggert's letter yesterday (in addition to a few others). The approach
5820 has been to make zic a bit smarter about figuring out what time zone
5821 abbreviations apply just after the time specified in the "UNTIL" part
5822 of a zone line. Putting the smarts in zic means avoiding having
5823 transition times show up in both "Zone" lines and "Rule" lines, which
5824 in turn avoids multiple transition time entries in time zone files.
5825 (This also makes the zic input files such as "europe" a bit shorter and
5826 should ease maintenance.)
5829 Release data96f - 1996-04-19 19:20:03 -0000
5830 [tzdata96f.tar.gz is missing!]
5832 The only changes are to the "northamerica" file; the time zone
5833 abbreviation for Denver is corrected to MST (and MDT), and the
5834 comments for Mexico have been updated.
5837 Release data96e - 1996-03-19 17:37:26 -0500
5839 Proposals by Paul Eggert, in particular the Portugal change that
5840 comes into play at the end of this month.
5843 Release data96d - 1996-03-18 20:49:39 -0500
5848 Release code96e - 1996-02-29 15:43:27 -0000
5849 [tzcode96e.tar.gz is missing!]
5851 internationalization changes and the fix to the documentation for strftime
5854 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5856 The "code" file simply updates Bob Kridle's electronic address.
5858 The "data" file updates rules for Mexico.
5861 Release data96b - 1996-01-27 15:44:42 -0500
5866 Release code96c - 1996-01-16 16:58:15 -0500
5868 leap-year streamlining and binary-search changes
5873 Release code96b - 1996-01-10 20:42:39 -0500
5875 fixes and enhancements from Paul Eggert, including code that
5876 emulates the behavior of recent versions of the SunOS "date"
5880 Release 96a - 1996-01-06 09:08:24 -0500
5884 fixes to strftime.c for correct ISO 8601 week number generation,
5885 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5886 numbers (which are not necessarily the same as calendar year numbers)
5889 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5891 The latest revisions from Paul Eggert are included, the usno1995
5892 file has been updated, and a new file ("WWW") covering useful URLs
5896 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5898 A simplification of a macro definition, a change to data for Sudan,
5899 and (for last minute shoppers) notes in the "Music" file on the CD
5903 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5905 (slightly reformatted) 8-bit-clean proposed patch
5907 minor patch: US/Eastern -> America/New_York
5909 snapshot of the USNO's latest data ("usno1995")
5911 some other minor cleanups
5914 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5915 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5919 support for 64-bit time_t's
5921 optimization in localtime.c
5924 Release code95e - 1995-10-13 13:23:57 -0400
5926 the mktime change to scan from future to past when trying to find time zone
5930 Release data95i - 1995-09-26 10:43:26 -0400
5932 For Canada/Central, guess that the Sun customer's "one week too
5933 early" was just a approximation, and the true error is one month
5934 too early. This is consistent with the rest of Canada.
5937 Release data95h - 1995-09-21 11:26:48 -0400
5939 latest changes from Paul Eggert
5942 Release code95d - 1995-09-14 11:14:45 -0400
5944 the addition of a "Music" file, which documents four recorded
5945 versions of the tune "Save That Time".
5948 Release data95g - 1995-09-01 17:21:36 -0400
5950 "yearistype" correction
5953 Release data95f - 1995-08-28 20:46:56 -0400
5955 Paul Eggert's change to the australasia file
5958 Release data95e - 1995-07-08 18:02:34 -0400
5960 The only change is a leap second at the end of this year.
5961 Thanks to Bradley White for forwarding news on the leap second.
5964 Release data95d - 1995-07-03 13:26:22 -0400
5966 Paul Eggert's changes
5969 Release data95c - 1995-07-02 19:19:28 -0400
5971 changes to "asia", "backward", "europe", and "southamerica"
5972 (read: northamericacentrics need not apply)
5975 Release code95c - 1995-03-13 14:00:46 -0500
5977 one-line fix for sign extension problems in detzcode
5980 Release 95b - 1995-03-04 11:22:38 -0500
5982 Minor changes in both:
5984 The "code" file contains a workaround for the lack of "unistd.h" in
5985 Microsoft C++ version 7.
5987 The "data" file contains a fixed "Link" for America/Shiprock.
5990 Release 94h - 1994-12-10 12:51:14 -0500
5994 * incorporate the changes to "zdump" and "date" to make changes to
5995 the "TZ" environment variable permanent;
5997 * incorporate the table changes by Paul Eggert;
5999 * include (and document) support for universal time specifications in
6000 data files - but do not (yet) include use of this feature in the
6003 Think of this as "TZ Classic" - the software has been set up not to break if
6004 universal time shows up in its input, and data entries have been
6005 left as is so as not to break existing implementations.
6008 Release data94f - 1994-08-20 12:56:09 -0400
6010 (with thanks!) the latest data updates from Paul Eggert
6013 Release data94e - 1994-06-04 13:13:53 -0400
6018 Release code94g - 1994-05-05 12:14:07 -0400
6020 fix missing "optind.c" and a reference to it in the Makefile
6023 Release code94f - 1994-05-05 13:00:33 -0000
6024 [tzcode94f.tar.gz is missing!]
6026 changes to avoid overflow in difftime, as well as changes to cope
6027 with the 52/53 challenge in strftime
6030 Release code94e - 1994-03-30 23:32:59 -0500
6032 change for the benefit of PCTS
6035 Release 94d - 1994-02-24 15:42:25 -0500
6037 Avoid clashes with POSIX semantics for zones such as GMT+4.
6039 Some other very minor housekeeping is also present.
6042 Release code94c - 1994-02-10 08:52:40 -0500
6044 Fix bug where mkdirs was broken unless you compile with
6045 -fwritable-strings (which is generally losing to do).
6048 Release 94b - 1994-02-07 10:04:33 -0500
6050 work by Paul Eggert who notes:
6052 I found another book of time zone histories by E W Whitman; it's not
6053 as extensive as Shanks but has a few goodies of its own. I used it
6054 to update the tables. I also fixed some more as a result of
6055 correspondence with Adam David and Peter Ilieve, and move some stray
6056 links from 'europe' to 'backward'. I corrected some scanning errors
6059 As far as the code goes, I fixed zic to allow years in the range
6060 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
6061 And I cleaned up the zic documentation a little bit.
6064 Release data94a - 1994-02-03 08:58:54 -0500
6066 It simply incorporates the recently announced leap second into the
6070 Release 93g - 1993-11-22 17:28:27 -0500
6072 Paul Eggert has provided a good deal of historic information (based
6073 on Shanks), and there are some code changes to deal with the buglets
6074 that crawled out in dealing with the new information.
6077 Release 93f - 1993-10-15 12:27:46 -0400
6079 Paul Eggert's changes
6082 Release 93e - 1993-09-05 21:21:44 -0400
6084 This has updated data for Israel, England, and Kwajalein. There's
6085 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
6086 Thanks to Paul Eggert and Peter Ilieve for the changes.
6089 Release 93d - 1993-06-17 23:34:17 -0400
6091 new fix and new data on Israel
6094 Release 93c - 1993-06-06 19:31:55 -0400
6099 Release 93b - 1993-02-02 14:53:58 -0500
6101 updated "leapseconds" file
6104 Release 93 - 1993-01-08 07:01:06 -0500
6106 At kre's suggestion, the package has been split in two - a code piece
6107 (which also includes documentation) that's only of use to folks who
6108 want to recompile things and a data piece useful to anyone who can
6111 The new version has a few changes to the data files, a few
6112 portability changes, and an off-by-one fix (with thanks to
6113 Tom Karzes at deshaw.com for providing a description and a
6117 Release 92c - 1992-11-21 17:35:36 -0000
6118 [tz92c.tar.Z is missing!]
6120 The fallout from the latest round of DST transitions.
6122 There are changes for Portugal, Saskatchewan, and "Pacific-New";
6123 there's also a change to "zic.c" that makes it portable to more systems.
6126 Release 92 - 1992-04-25 18:17:03 -0000
6127 [tz92.tar.Z is missing!]
6129 By popular demand (well, at any rate, following a request by kre at munnari)
6132 The 1989 update of the time zone package featured:
6134 * POSIXization (including interpretation of POSIX-style TZ environment
6135 variables, provided by Guy Harris),
6136 * ANSIfication (including versions of "mktime" and "difftime"),
6137 * SVIDulation (an "altzone" variable)
6138 * MACHination (the "gtime" function)
6139 * corrections to some time zone data (including corrections to the rules
6140 for Great Britain and New Zealand)
6141 * reference data from the United States Naval Observatory for folks who
6142 want to do additional time zones
6143 * and the 1989 data for Saudi Arabia.
6145 (Since this code will be treated as "part of the implementation" in some
6146 places and as "part of the application" in others, there's no good way to
6147 name functions, such as timegm, that are not part of the proposed ANSI C
6148 standard; such functions have kept their old, underscore-free names in this
6151 And the "dysize" function has disappeared; it was present to allow
6152 compilation of the "date" command on old BSD systems, and a version of "date"
6153 is now provided in the package. The "date" command is not created when you
6154 "make all" since it may lack options provided by the version distributed with
6155 your operating system, or may not interact with the system in the same way
6156 the native version does.
6158 Since POSIX frowns on correct leap second handling, the default behavior of
6159 the "zic" command (in the absence of a "-L" option) has been changed to omit
6160 leap second information from its output files.
6166 This file contains copies of the part of each release announcement
6167 that talks about the changes in that release. The text has been
6168 adapted and reformatted for the purposes of this file.
6170 Traditionally a release R consists of a pair of tarball files,
6171 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
6172 code2010a, data2012c) consist of just one or the other tarball, and a
6173 few (e.g., code2012c-data2012d) have tarballs with mixed version
6174 numbers. Recent releases also come in an experimental format
6175 consisting of a single tarball tzdb-R.tar.lz with extra data.
6177 Release timestamps are taken from the release's commit (for newer,
6178 Git-based releases), from the newest file in the tarball (for older
6179 releases, where this info is available) or from the email announcing
6180 the release (if all else fails; these are marked with a time zone
6181 abbreviation of -0000 and an "is missing!" comment).
6183 Earlier versions of the code and data were not announced on the tz
6184 list and are not summarized here.
6186 This file is in the public domain.