1 News for the tz database
3 Release 2023d - 2023-12-21 20:02:24 -0800
6 Ittoqqortoormiit, Greenland changes time zones on 2024-03-31.
7 Vostok, Antarctica changed time zones on 2023-12-18.
8 Casey, Antarctica changed time zones five times since 2020.
9 Code and data fixes for Palestine timestamps starting in 2072.
10 A new data file zonenow.tab for timestamps starting now.
12 Changes to future timestamps
14 Ittoqqortoormiit, Greenland (America/Scoresbysund) joins most of
15 the rest of Greenland's timekeeping practice on 2024-03-31, by
16 changing its time zone from -01/+00 to -02/-01 at the same moment
17 as the spring-forward transition. Its clocks will therefore not
18 spring forward as previously scheduled. The time zone change
19 reverts to its common practice before 1981.
21 Fix predictions for DST transitions in Palestine in 2072-2075,
22 correcting a typo introduced in 2023a.
24 Changes to past and future timestamps
26 Vostok, Antarctica changed to +05 on 2023-12-18. It had been at
27 +07 (not +06) for years. (Thanks to Zakhary V. Akulov.)
29 Change data for Casey, Antarctica to agree with timeanddate.com,
30 by adding five time zone changes since 2020. Casey is now at +08
33 Changes to past tm_isdst flags
35 Much of Greenland, represented by America/Nuuk, changed its
36 standard time from -03 to -02 on 2023-03-25, not on 2023-10-28.
37 This does not affect UTC offsets, only the tm_isdst flag.
38 (Thanks to Thomas M. Steenholdt.)
42 A new data file zonenow.tab helps configure applications that use
43 timestamps dated from now on. This simplifies configuration,
44 since users choose from a smaller Zone set. The file's format is
45 experimental and subject to change.
49 localtime.c no longer mishandles TZif files that contain a single
50 transition into a DST regime. Previously, it incorrectly assumed
51 DST was in effect before the transition too. (Thanks to Alois
52 Treindl for debugging help.)
54 localtime.c's timeoff no longer collides with OpenBSD 7.4.
56 The C code now uses _Generic only if __STDC_VERSION__ says the
57 compiler is C11 or later.
59 tzselect now optionally reads zonenow.tab, to simplify when
60 configuring only for timestamps dated from now on.
62 tzselect no longer creates temporary files.
64 tzselect no longer mishandles the following:
66 Spaces and most other special characters in BUGEMAIL, PACKAGE,
69 TZ strings when using mawk 1.4.3, which mishandles regular
70 expressions of the form /X{2,}/.
72 ISO 6709 coordinates when using an awk that lacks the GNU
73 extension of newlines in -v option-arguments.
75 Non UTF-8 locales when using an iconv command that lacks the GNU
78 zic no longer mishandles data for Palestine after the year 2075.
79 Previously, it incorrectly omitted post-2075 transitions that are
80 predicted for just before and just after Ramadan. (Thanks to Ken
81 Murchison for debugging help.)
83 zic now works again on Linux 2.6.16 and 2.6.17 (2006).
84 (Problem reported by Rune Torgersen.)
86 Changes to build procedure
88 The Makefile is now more compatible with POSIX:
89 * It no longer defines AR, CC, CFLAGS, LDFLAGS, and SHELL.
90 * It no longer uses its own 'cc' in place of CC.
91 * It now uses ARFLAGS, with default specified by POSIX.
92 * It does not use LFLAGS incompatibly with POSIX.
93 * It uses the special .POSIX target.
94 * It quotes special characters more carefully.
95 * It no longer mishandles builds in an ISO 8859 locale.
96 Due to the CC changes, TZDIR is now #defined in a file tzfile.h
97 built by 'make', not in a $(CC) -D option. Also, TZDEFAULT is
98 now treated like TZDIR as they have similar roles.
100 Changes to commentary
102 Limitations and hazards of the optional support for obsolescent
103 C89 platforms are documented better, along with a tentative
104 schedule for removing this support.
107 Release 2023c - 2023-03-28 12:42:14 -0700
109 Changes to past and future timestamps
111 Model Lebanon's DST chaos by reverting data to tzdb 2023a.
112 (Thanks to Rany Hany for the heads-up.)
115 Release 2023b - 2023-03-23 19:50:38 -0700
117 Changes to future timestamps
119 This year Lebanon springs forward April 20/21 not March 25/26.
120 (Thanks to Saadallah Itani.) [This was reverted in 2023c.]
123 Release 2023a - 2023-03-22 12:39:33 -0700
126 Egypt now uses DST again, from April through October.
127 This year Morocco springs forward April 23, not April 30.
128 Palestine delays the start of DST this year.
129 Much of Greenland still uses DST from 2024 on.
130 America/Yellowknife now links to America/Edmonton.
131 tzselect can now use current time to help infer timezone.
132 The code now defaults to C99 or later.
133 Fix use of C23 attributes.
135 Changes to future timestamps
137 Starting in 2023, Egypt will observe DST from April's last Friday
138 through October's last Thursday. (Thanks to Ahmad ElDardiry.)
139 Assume the transition times are 00:00 and 24:00, respectively.
141 In 2023 Morocco's spring-forward transition after Ramadan
142 will occur April 23, not April 30. (Thanks to Milamber.)
143 Adjust predictions for future years accordingly. This affects
144 predictions for 2023, 2031, 2038, and later years.
146 This year Palestine will delay its spring forward from
147 March 25 to April 29 due to Ramadan. (Thanks to Heba Hamad.)
148 Make guesses for future Ramadans too.
150 Much of Greenland, represented by America/Nuuk, will continue to
151 observe DST using European Union rules. When combined with
152 Greenland's decision not to change the clocks in fall 2023,
153 America/Nuuk therefore changes from -03/-02 to -02/-01 effective
154 2023-10-29 at 01:00 UTC. (Thanks to Thomas M. Steenholdt.)
155 This change from 2022g doesn't affect timestamps until 2024-03-30,
156 and doesn't affect tm_isdst until 2023-03-25.
158 Changes to past timestamps
160 America/Yellowknife has changed from a Zone to a backward
161 compatibility Link, as it no longer differs from America/Edmonton
162 since 1970. (Thanks to Almaz Mingaleev.) This affects some
163 pre-1948 timestamps. The old data are now in 'backzone'.
165 Changes to past time zone abbreviations
167 When observing Moscow time, Europe/Kirov and Europe/Volgograd now
168 use the abbreviations MSK/MSD instead of numeric abbreviations,
169 for consistency with other timezones observing Moscow time.
173 You can now tell tzselect local time, to simplify later choices.
174 Select the 'time' option in its first prompt.
176 You can now compile with -DTZNAME_MAXIMUM=N to limit time zone
177 abbreviations to N bytes (default 255). The reference runtime
178 library now rejects POSIX-style TZ strings that contain longer
179 abbreviations, treating them as UTC. Previously the limit was
180 platform dependent and abbreviations were silently truncated to
181 16 bytes even when the limit was greater than 16.
183 The code by default is now designed for C99 or later. To build on
184 a mostly-C89 platform, compile with -DPORT_TO_C89; this should
185 work on C89 platforms that also support C99 'long long' and
186 perhaps a few other extensions to C89. To support C89 callers of
187 tzcode's library, compile with -DSUPPORT_C89; however, this could
188 trigger latent bugs in C99-or-later callers. The two new macros
189 are transitional aids planned to be removed in a future version
190 (say, in 2029), when C99 or later will be required.
192 The code now builds again on pre-C99 platforms, if you compile
193 with -DPORT_TO_C89. This fixes a bug introduced in 2022f.
195 On C23-compatible platforms tzcode no longer uses syntax like
196 'static [[noreturn]] void usage(void);'. Instead, it uses
197 '[[noreturn]] static void usage(void);' as strict C23 requires.
198 (Problem reported by Houge Langley.)
200 The code's functions now constrain their arguments with the C
201 'restrict' keyword consistently with their documentation.
202 This may allow future optimizations.
204 zdump again builds standalone with ckdadd and without setenv,
205 fixing a bug introduced in 2022g. (Problem reported by panic.)
207 leapseconds.awk can now process a leap seconds file that never
208 expires; this might be useful if leap seconds are discontinued.
210 Changes to commentary
212 tz-link.html has a new section "Coordinating with governments and
213 distributors". (Thanks to Neil Fuller for some of the text.)
215 To improve tzselect diagnostics, zone1970.tab's comments column is
216 now limited to countries that have multiple timezones.
218 Note that leap seconds are planned to be discontinued by 2035.
221 Release 2022g - 2022-11-29 08:58:31 -0800
224 The northern edge of Chihuahua changes to US timekeeping.
225 Much of Greenland stops changing clocks after March 2023.
226 Fix some pre-1996 timestamps in northern Canada.
227 C89 is now deprecated; please use C99 or later.
228 Portability fixes for AIX, libintl, MS-Windows, musl, z/OS
229 In C code, use more C23 features if available.
230 C23 timegm now supported by default
231 Fixes for unlikely integer overflows
233 Changes to future timestamps
235 In the Mexican state of Chihuahua, the border strip near the US
236 will change to agree with nearby US locations on 2022-11-30.
237 The strip's western part, represented by Ciudad Juárez, switches
238 from -06 all year to -07/-06 with US DST rules, like El Paso, TX.
239 The eastern part, represented by Ojinaga, will observe US DST next
240 year, like Presidio, TX. (Thanks to Heitor David Pinto.)
241 A new Zone America/Ciudad_Juarez splits from America/Ojinaga.
243 Much of Greenland, represented by America/Nuuk, stops observing
244 winter time after March 2023, so its daylight saving time becomes
245 standard time. (Thanks to Jonas Nyrup and Jürgen Appel.)
247 Changes to past timestamps
249 Changes for pre-1996 northern Canada (thanks to Chris Walton):
251 Merge America/Iqaluit and America/Pangnirtung into the former,
252 with a backward compatibility link for the latter name.
253 There is no good evidence the two locations differ since 1970.
254 This change affects pre-1996 America/Pangnirtung timestamps.
256 Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and
257 Yellowknife did not observe DST in 1965, and did observe DST
258 from 1972 through 1979.
260 Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28.
262 Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00.
263 (Thanks to Alois Treindl.)
265 Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time),
266 not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.)
270 Although tzcode still works with C89, bugs found in recent routine
271 maintenance indicate that bitrot has set in and that in practice
272 C89 is no longer used to build tzcode. As it is a maintenance
273 burden, support for C89 is planned to be removed soon. Instead,
274 please use compilers compatible with C99, C11, C17, or C23.
276 timegm, which tzcode implemented in 1989, will finally be
277 standardized 34 years later as part of C23, so timegm is now
278 supported even if STD_INSPIRED is not defined.
280 Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone.
281 (Problem reported by Đoàn Trần Công Danh.)
283 Fix bug in zic on hosts where malloc(0) yields NULL on success.
284 (Problem reported by Tim McBrayer for AIX 6.1.)
286 Fix zic configuration to avoid linkage failures on some platforms.
287 (Problems reported by Gilmore Davidson and Igor Ivanov.)
289 Work around MS-Windows nmake incompatibility with POSIX.
290 (Problem reported by Manuela Friedrich.)
292 Port mktime and strftime to debugging platforms where accessing
293 uninitialized data has undefined behavior (strftime problem
294 reported by Robert Elz).
296 Check more carefully for unlikely integer overflows, preferring
297 C23 <stdckdint.h> to overflow checking by hand, as the latter has
300 Changes to build procedure
302 New Makefile rule check_mild that skips checking whether Link
303 lines are in the file 'backward'. (Inspired by a suggestion from
307 Release 2022f - 2022-10-28 18:04:57 -0700
310 Mexico will no longer observe DST except near the US border.
311 Chihuahua moves to year-round -06 on 2022-10-30.
312 Fiji no longer observes DST.
313 Move links to 'backward'.
314 In vanguard form, GMT is now a Zone and Etc/GMT a link.
315 zic now supports links to links, and vanguard form uses this.
316 Simplify four Ontario zones.
317 Fix a Y2438 bug when reading TZif data.
318 Enable 64-bit time_t on 32-bit glibc platforms.
319 Omit large-file support when no longer needed.
320 In C code, use some C23 features if available.
321 Remove no-longer-needed workaround for Qt bug 53071.
323 Changes to future timestamps
325 Mexico will no longer observe DST after 2022, except for areas
326 near the US border that continue to observe US DST rules.
327 On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
328 from -07 (-06 with DST) to year-round -06, thus not changing
329 its clocks that day. The new law states that Chihuahua
330 near the US border no longer observes US DST.
331 (Thanks to gera for the heads-up about Chihuahua.)
333 Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.)
334 For now, assume DST is suspended indefinitely.
338 Move links to 'backward' to ease and simplify link maintenance.
339 This affects generated data only if you use 'make BACKWARD='.
341 GMT is now a Zone and Etc/GMT a link instead of vice versa,
342 as GMT is needed for leap second support whereas Etc/GMT is not.
343 However, this change exposes a bug in TZUpdater 2.3.2 so it is
344 present only in vanguard form for now.
346 Vanguard form now uses links to links, as zic now supports this.
348 Changes to past timestamps
350 Simplify four Ontario zones, as most of the post-1970 differences
351 seem to have been imaginary. (Problem reported by Chris Walton.)
352 Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay
353 to 'backzone'; backward-compatibility links still work, albeit
354 with some different timestamps before November 2005.
358 zic now supports links to links regardless of input line order.
359 For example, if Australia/Sydney is a Zone, the lines
360 Link Australia/Canberra Australia/ACT
361 Link Australia/Sydney Australia/Canberra
362 now work correctly, even though the shell commands
363 ln Australia/Canberra Australia/ACT
364 ln Australia/Sydney Australia/Canberra
365 would fail because the first command attempts to use a link
366 Australia/Canberra that does not exist until after the second
367 command is executed. Previously, zic had unspecified behavior if
368 a Link line's target was another link, and zic often misbehaved if
369 a Link line's target was a later Link line.
371 Fix line number in zic's diagnostic for a link to a link.
373 Fix a bug that caused localtime to mishandle timestamps starting
374 in the year 2438 when reading data generated by 'zic -b fat' when
375 distant-future DST transitions occur at times given in standard
376 time or in UT, not the usual case of local time. This occurs when
377 the corresponding .zi Rule lines specify DST transitions with TO
378 columns of 'max' and AT columns that end in 's' or 'u'. The
379 number 2438 comes from the 32-bit limit in the year 2038, plus the
380 400-year Gregorian cycle. (Problem reported by Bradley White.)
382 On glibc 2.34 and later, which optionally supports 64-bit time_t
383 on platforms like x86 where time_t was traditionally 32 bits,
384 default time_t to 64 instead of 32 bits. This lets functions like
385 localtime support timestamps after the year 2038, and fixes
386 year-2038 problems in zic when accessing files dated after 2038.
387 To continue to limit time_t to 32 bits on these platforms, use
388 "make CFLAGS='-D_TIME_BITS=32'".
390 In C code, do not enable large-file support on platforms like AIX
391 and macOS that no longer need it now that tzcode does not use
392 off_t or related functions like 'stat'. Large-file support is
393 still enabled by default on GNU/Linux, as it is needed for 64-bit
396 In C code, prefer C23 keywords to pre-C23 macros for alignof,
397 bool, false, and true. Also, use the following C23 features if
398 available: __has_include, unreachable.
400 zic no longer works around Qt bug 53071, as the relevant Qt
401 releases have been out of support since 2019. This change affects
402 only fat TZif files, as thin files never had the workaround.
404 zdump no longer modifies the environ vector when compiled on
405 platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
406 This avoid undefined behavior on POSIX platforms.
409 Release 2022e - 2022-10-11 11:13:02 -0700
412 Jordan and Syria switch from +02/+03 with DST to year-round +03.
414 Changes to future timestamps
416 Jordan and Syria are abandoning the DST regime and are changing to
417 permanent +03, so they will not fall back from +03 to +02 on
418 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.)
420 Changes to past timestamps
422 On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00.
424 Changes to past time zone abbreviations and DST flags
426 The temporary advancement of clocks in central Mexico in summer
427 1931 is now treated as daylight saving time, instead of as two
428 changes to standard time.
431 Release 2022d - 2022-09-23 12:02:57 -0700
434 Palestine transitions are now Saturdays at 02:00.
435 Simplify three Ukraine zones into one.
437 Changes to future timestamps
439 Palestine now springs forward and falls back at 02:00 on the
440 first Saturday on or after March 24 and October 24, respectively.
441 This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00.
442 (Thanks to Heba Hamad.)
444 Changes to past timestamps
446 Simplify three Ukraine zones to one, since the post-1970
447 differences seem to have been imaginary. Move Europe/Uzhgorod and
448 Europe/Zaporozhye to 'backzone'; backward-compatibility links
449 still work, albeit with different timestamps before October 1991.
452 Release 2022c - 2022-08-15 17:47:18 -0700
455 Work around awk bug in FreeBSD, macOS, etc.
456 Improve tzselect on intercontinental Zones.
460 Work around a bug in onetrueawk that broke commands like
461 'make traditional_tarballs' on FreeBSD, macOS, etc.
462 (Problem reported by Deborah Goldsmith.)
464 Add code to tzselect that uses experimental structured comments in
465 zone1970.tab to clarify whether Zones like Africa/Abidjan and
466 Europe/Istanbul cross continent or ocean boundaries.
467 (Inspired by a problem reported by Peter Krefting.)
469 Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
470 directory /a/b already exists.
472 Remove zoneinfo2tdf.pl, as it was unused and triggered false
473 malware alarms on some email servers.
476 Release 2022b - 2022-08-10 15:38:32 -0700
479 Chile's DST is delayed by a week in September 2022.
480 Iran no longer observes DST after 2022.
481 Rename Europe/Kiev to Europe/Kyiv.
483 Vanguard form now uses %z.
484 Finish moving duplicate-since-1970 zones to 'backzone'.
485 New build option PACKRATLIST
486 New tailored_tarballs target, replacing rearguard_tarballs
488 Changes to future timestamps
490 Chile's 2022 DST start is delayed from September 4 to September 11.
491 (Thanks to Juan Correa.)
493 Iran plans to stop observing DST permanently, after it falls back
494 on 2022-09-21. (Thanks to Ali Mirjamali.)
496 Changes to past timestamps
498 Finish moving to 'backzone' the location-based zones whose
499 timestamps since 1970 are duplicates; adjust links accordingly.
500 This change ordinarily affects only pre-1970 timestamps, and with
501 the new PACKRATLIST option it does not affect any timestamps.
502 In this round the affected zones are Antarctica/Vostok,
503 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
504 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
505 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
506 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
507 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
508 Pacific/Wake and Pacific/Wallis, and the affected links are
509 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
510 Pacific/Truk, and Pacific/Yap.
512 From fall 1994 through fall 1995, Shanks wrote that Crimea's
513 DST transitions were at 02:00 standard time, not at 00:00.
514 (Thanks to Michael Deckers.)
516 Iran adopted standard time in 1935, not 1946. In 1977 it observed
517 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
518 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
519 transition was on 05-27, not 03-21.
520 (Thanks to Roozbeh Pournader and Francis Santoni.)
522 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
523 considered DST, not standard time. Santiago and environs had moved
524 their clocks back to rejoin the rest of mainland Chile; put this
525 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
527 Some old, small clock transitions have been removed, as people at
528 the time did not change their clocks. This affects Asia/Hong_Kong
529 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
533 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
534 English now. Spelling of other names in Ukraine has not yet
535 demonstrably changed in common English practice so for now these
536 names retain old spellings, as in other countries (e.g.,
537 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
541 zic has a new option '-R @N' to output explicit transitions < N.
542 (Need suggested by Almaz Mingaleev.)
544 'zic -r @N' no longer outputs bad data when N < first transition.
545 (Problem introduced in 2021d and reported by Peter Krefting.)
547 zic now checks its input for NUL bytes and unterminated lines, and
548 now supports input line lengths up to 2048 (not 512) bytes.
550 gmtime and related code now use the abbreviation "UTC" not "GMT".
551 POSIX is being revised to require this.
553 When tzset and related functions set vestigial static variables
554 like tzname, they now prefer specified timestamps to unspecified ones.
555 (Problem reported by Almaz Mingaleev.)
557 zic no longer complains "can't determine time zone abbreviation to
558 use just after until time" when a transition to a new standard
559 time occurs simultaneously with the first DST fallback transition.
561 Changes to build procedure
563 Source data in vanguard form now uses the %z notation, introduced
564 in release 2015f. For example, for America/Sao_Paulo vanguard
565 form contains the zone continuation line "-3:00 Brazil %z", which
566 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
567 used in main and rearguard forms. The plan is for the main form
568 to use %z eventually; in the meantime maintainers of zi parsers
569 are encouraged to test the parsers on vanguard.zi.
571 The Makefile has a new PACKRATLIST option to select a subset of
572 'backzone'. For example, 'make PACKRATDATA=backzone
573 PACKRATLIST=zone.tab' now generates TZif files identical to those
574 of the global-tz project.
576 The Makefile has a new tailored_tarballs target for generating
577 special-purpose tarballs. It generalizes and replaces the
578 rearguard_tarballs target and related targets and macros, which
581 'make install' now defaults LOCALTIME to Factory not GMT,
582 which means the default abbreviation is now "-00" not "GMT".
584 Remove the posix_packrat target, marked obsolescent in 2016a.
587 Release 2022a - 2022-03-15 23:02:01 -0700
590 Palestine will spring forward on 2022-03-27, not -03-26.
591 zdump -v now outputs better failure indications.
592 Bug fixes for code that reads corrupted TZif data.
594 Changes to future timestamps
596 Palestine will spring forward on 2022-03-27, not 2022-03-26.
597 (Thanks to Heba Hamad.) Predict future transitions for first
598 Sunday >= March 25. Additionally, predict fallbacks to be the first
599 Friday on or after October 23, not October's last Friday, to be more
600 consistent with recent practice. The first differing fallback
601 prediction is on 2025-10-24, not 2025-10-31.
603 Changes to past timestamps
605 From 1992 through spring 1996, Ukraine's DST transitions were at
606 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
608 Chile's Santiago Mean Time and its LMT precursor have been adjusted
609 eastward by 1 second to align with past and present law.
611 Changes to commentary
613 Add several references for Chile's 1946/1947 transitions, some of
614 which only affected portions of the country.
618 Fix bug when mktime gets confused by truncated TZif files with
619 unspecified local time. (Problem reported by Almaz Mingaleev.)
621 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
622 (Problem reported by Christos Zoulas.)
624 When reading a version 2 or later TZif file, the TZif reader now
625 validates the version 1 header and data block only enough to skip
626 over them, as recommended by RFC 8536 section 4. Also, the TZif
627 reader no longer mistakenly attempts to parse a version 1 TZIf
628 file header as a TZ string.
630 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
631 when local time and UT cannot be determined for a timestamp.
633 Changes to build procedure
635 Distribution tarballs now use standard POSIX.1-1988 ustar format
636 instead of GNU format. Although the formats are almost identical
637 for these tarballs, ustar headers' magic fields contain "ustar"
638 instead of "ustar ", and their version fields contain "00" instead
639 of " ". The two formats are planned to diverge more significantly
640 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
641 format becomes obsolete and the tarballs switch to pax format, an
642 extension of ustar. For details about these formats, please see
643 "pax - portable archive interchange", IEEE Std 1003.1-2017,
644 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
647 Release 2021e - 2021-10-21 18:41:00 -0700
649 Changes to future timestamps
651 Palestine will fall back 10-29 (not 10-30) at 01:00.
652 (Thanks to P Chan and Heba Hemad.)
655 Release 2021d - 2021-10-15 13:48:18 -0700
658 Fiji suspends DST for the 2021/2022 season.
659 'zic -r' marks unspecified timestamps with "-00".
661 Changes to future timestamps
663 Fiji will suspend observance of DST for the 2021/2022 season.
664 Assume for now that it will return next year. (Thanks to Jashneel
669 'zic -r' now uses "-00" time zone abbreviations for intervals
670 with UT offsets that are unspecified due to -r truncation.
671 This implements a change in draft Internet RFC 8536bis.
674 Release 2021c - 2021-10-01 14:21:49 -0700
677 Revert most 2021b changes to 'backward'.
678 Fix 'zic -b fat' bug in pre-1970 32-bit data.
679 Fix two Link line typos.
680 Distribute SECURITY file.
682 This release is intended as a bugfix release, to fix compatibility
683 problems and typos reported since 2021b was released.
685 Changes to Link directives
687 Revert almost all of 2021b's changes to the 'backward' file,
688 by moving Link directives back to where they were in 2021a.
689 Although 'zic' doesn't care which source file contains a Link
690 directive, some downstream uses ran into trouble with the move.
691 (Problem reported by Stephen Colebourne for Joda-Time.)
693 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
694 (problem reported by Chris Walton).
696 Fix 'backzone' typo that linked America/Virgin to the wrong
697 location (problem reported by Michael Deckers).
701 Fix a bug in 'zic -b fat' that caused old timestamps to be
702 mishandled in 32-bit-only readers (problem reported by Daniel
705 Changes to documentation
707 Distribute the SECURITY file (problem reported by Andreas Radke).
710 Release 2021b - 2021-09-24 16:23:00 -0700
713 Jordan now starts DST on February's last Thursday.
714 Samoa no longer observes DST.
715 Merge more location-based Zones whose timestamps agree since 1970.
716 Move some backward-compatibility links to 'backward'.
717 Rename Pacific/Enderbury to Pacific/Kanton.
718 Correct many pre-1993 transitions in Malawi, Portugal, etc.
719 zic now creates each output file or link atomically.
720 zic -L no longer omits the POSIX TZ string in its output.
721 zic fixes for truncation and leap second table expiration.
722 zic now follows POSIX for TZ strings using all-year DST.
723 Fix some localtime crashes and bugs in obscure cases.
724 zdump -v now outputs more-useful boundary cases.
725 tzfile.5 better matches a draft successor to RFC 8536.
728 This release is prompted by recent announcements by Jordan and Samoa.
729 It incorporates many other changes that had accumulated since 2021a.
730 However, it omits most proposed changes that merged all Zones
731 agreeing since 1970, as concerns were raised about doing too many of
732 these changes at once. It does keeps some of these changes in the
733 interest of making tzdb more equitable one step at a time; see
734 "Merge more location-based Zones" below.
736 Changes to future timestamps
738 Jordan now starts DST on February's last Thursday.
739 (Thanks to Steffen Thorsen.)
741 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
745 Rename Pacific/Enderbury to Pacific/Kanton. When we added
746 Enderbury in 1993, we did not know that it is uninhabited and that
747 Kanton (population two dozen) is the only inhabited location in
748 that timezone. The old name is now a backward-compatibility link.
750 Changes to past timestamps
752 Correct many pre-1993 transitions, fixing entries originally
753 derived from Shanks, Whitman, and Mundell. The fixes include:
754 - Barbados: standard time was introduced in 1911, not 1932; and
755 DST was observed in 1942-1944
756 - Cook Islands: In 1899 they switched from east to west of GMT,
757 celebrating Christmas for two days. They (and Niue) switched
758 to standard time in 1952, not 1901.
759 - Guyana: corrected LMT for Georgetown; the introduction of
760 standard time in 1911, not 1915; and corrections to 1975 and
762 - Kanton: uninhabited before 1937-08-31
763 - Niue: only observed -11:20 from 1952 through 1964, then went to
764 -11 instead of -11:30
765 - Portugal: DST was observed in 1950
766 - Tonga: corrected LMT; the introduction of standard time in 1945,
767 not 1901; and corrections to the transition from +12:20 to +13
769 Additional fixes to entries in the 'backzone' file include:
770 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
771 - The Gambia: 1933 and 1942 transitions
772 - Malawi: several 1911 through 1925 transitions
773 - Sierra Leone: several 1913 through 1941 transitions, and DST
774 was NOT observed in 1957 through 1962
775 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
778 Merge more location-based Zones whose timestamps agree since 1970,
779 as pre-1970 timestamps are out of scope. This is part of a
780 process that has been ongoing since 2013. This does not affect
781 post-1970 timestamps, and timezone historians who build with 'make
782 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
783 When merging, keep the most-populous location's data, and move
784 data for other locations to 'backzone' with a backward
785 link in 'backward'. For example, move America/Creston data to
786 'backzone' with a link in 'backward' from America/Phoenix because
787 the two timezones' timestamps agree since 1970; this change
788 affects some pre-1968 timestamps in America/Creston because
789 Creston and Phoenix disagreed before 1968. The affected Zones
790 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
791 America/Creston, America/Curacao, America/Nassau,
792 America/Port_of_Spain, Antarctica/DumontDUrville, and
795 Changes to maintenance procedure
797 The new file SECURITY covers how to report security-related bugs.
799 Several backward-compatibility links have been moved to the
800 'backward' file. These links, which range from Africa/Addis_Ababa
801 to Pacific/Saipan, are only for compatibility with now-obsolete
802 guidelines suggesting an entry for every ISO 3166 code.
803 The intercontinental convenience links Asia/Istanbul and
804 Europe/Nicosia have also been moved to 'backward'.
808 zic now creates each output file or link atomically,
809 possibly by creating a temporary file and then renaming it.
810 This avoids races where a TZ setting would temporarily stop
811 working while zic was installing a replacement file or link.
813 zic -L no longer omits the POSIX TZ string in its output.
814 Starting with 2020a, zic -L truncated its output according to the
815 "Expires" directive or "#expires" comment in the leapseconds file.
816 The resulting TZif files omitted daylight saving transitions after
817 the leap second table expired, which led to far less accurate
818 predictions of times after the expiry. Although future timestamps
819 cannot be converted accurately in the presence of leap seconds, it
820 is more accurate to convert near-future timestamps with a few
821 seconds error than with an hour error, so zic -L no longer
822 truncates output in this way.
824 Instead, when zic -L is given the "Expires" directive, it now
825 outputs the expiration by appending a no-change entry to the leap
826 second table. Although this should work well with most TZif
827 readers, it does not conform to Internet RFC 8536 and some pickier
828 clients (including tzdb 2017c through 2021a) reject it, so
829 "Expires" directives are currently disabled by default. To enable
830 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
831 this new feature it is marked with a new TZif version number 4,
832 a format intended to be documented in a successor to RFC 8536.
833 The old-format "#expires" comments are now treated solely as
834 comments and have no effect on the TZif files.
836 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
837 that omits leap second information for the range LO..B when LO
838 falls between two leap seconds A and B. Instead, it generates a
839 TZif version 4 file that represents the previously missing
842 The TZif reader now allows the leap second table to begin with a
843 correction other than -1 or +1, and to contain adjacent
844 transitions with equal corrections. This supports TZif version 4.
846 The TZif reader now lets leap seconds occur less than 28 days
847 apart. This supports possible future TZif extensions.
849 Fix bug that caused 'localtime' etc. to crash when TZ was
850 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
851 not conform to POSIX but does conform to Internet RFC 8536.
853 Fix another bug that caused 'localtime' etc. to crash when TZ was
854 set to a POSIX-conforming but unusual TZ string like
855 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
857 Fix yet another bug that caused 'localtime' etc. to mishandle slim
858 TZif files containing leap seconds after the last explicit
859 transition in the table, or when handling far-future timestamps
860 in slim TZif files lacking leap seconds.
862 Fix localtime misbehavior involving positive leap seconds.
863 This change affects only behavior for "right" system time,
864 which contains leap seconds, and only if the UT offset is
865 not a multiple of 60 seconds when a positive leap second occurs.
866 (No such timezone exists in tzdb, luckily.) Without the fix,
867 the timestamp was ambiguous during a positive leap second.
868 With the fix, any seconds occurring after a positive leap second
869 and within the same localtime minute are counted through 60, not
870 through 59; their UT offset (tm_gmtoff) is the same as before.
871 Here is how the fix affects timestamps in a timezone with UT
872 offset +01:23:45 (5025 seconds) and with a positive leap second at
873 1972-06-30 23:59:60 UTC (78796800):
875 time_t without the fix with the fix
876 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
877 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
879 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
880 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
882 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
883 civil time changes a few seconds before time_t wraps around, when
884 leap seconds are enabled.
886 Fix bug in zic -r; in some cases, the dummy time type after the
887 last time transition disagreed with the TZ string, contrary to
888 Internet RFC 8563 section 3.3.
890 Fix a bug with 'zic -r @X' when X is a negative leap second that
891 has a nonnegative correction. Without the fix, the output file
892 was truncated so that X appeared to be a positive leap second.
893 Fix a similar, even less likely bug when truncating at a positive
894 leap second that has a nonpositive correction.
896 zic -r now reports an error if given rolling leap seconds, as this
897 usage has never generally worked and is evidently unused.
899 zic now generates a POSIX-conforming TZ string for TZif files
900 where all-year DST is predicted for the indefinite future.
901 For example, for all-year Eastern Daylight Time, zic now generates
902 "XXX3EDT4,0/0,J365/23" where it previously generated
903 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
904 noting the possibility of POSIX conformance.)
906 zic.c no longer requires sys/wait.h (thanks to spazmodius for
907 noting it wasn't needed).
909 When reading slim TZif files, zdump no longer mishandles leap
910 seconds on the rare platforms where time_t counts leap seconds,
911 fixing a bug introduced in 2014g.
913 zdump -v now outputs timestamps at boundaries of what localtime
914 and gmtime can represent, instead of the less useful timestamps
915 one day after the minimum and one day before the maximum.
916 (Thanks to Arthur David Olson for prototype code, and to Manuela
917 Friedrich for debugging help.)
919 zdump's -c and -t options are now consistently inclusive for the
920 lower time bound and exclusive for the upper. Formerly they were
921 inconsistent. (Confusion noted by Martin Burnicki.)
923 Changes to build procedure
925 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
926 non-POSIX hosts where malloc doesn't set errno.
927 (Problem reported by Jan Engelhardt.)
929 Changes to documentation
931 tzfile.5 better matches a draft successor to RFC 8536
932 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
935 Release 2021a - 2021-01-24 10:54:57 -0800
937 Changes to future timestamps
939 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
940 (Thanks to Steffen Thorsen.)
943 Release 2020f - 2020-12-29 00:17:46 -0800
945 Change to build procedure
947 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
948 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
951 Release 2020e - 2020-12-22 15:14:34 -0800
954 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
956 Changes to future timestamps
958 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
959 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
961 Changes to past timestamps
963 Correct many pre-1986 transitions, fixing entries originally
964 derived from Shanks. The fixes include:
965 - Australia: several 1917 through 1971 transitions
966 - The Bahamas: several 1941 through 1945 transitions
967 - Bermuda: several 1917 through 1956 transitions
968 - Belize: several 1942 through 1968 transitions
969 - Ghana: several 1915 through 1956 transitions
970 - Israel and Palestine: several 1940 through 1985 transitions
971 - Kenya and adjacent: several 1908 through 1960 transitions
972 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
973 through 1919 transitions
974 - Seychelles: the introduction of standard time in 1907, not 1906
975 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
978 Because of the Australia change, Australia/Currie (King Island) is
979 no longer needed, as it is identical to Australia/Hobart for all
980 timestamps since 1970 and was therefore created by mistake.
981 Australia/Currie has been moved to the 'backward' file and its
982 corrected data moved to the 'backzone' file.
984 Changes to past time zone abbreviations and DST flags
986 To better match legislation in Turks and Caicos, the 2015 shift to
987 year-round observance of -04 is now modeled as AST throughout before
988 returning to Eastern Time with US DST in 2018, rather than as
989 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
991 Changes to documentation
993 The zic man page now documents zic's coalescing of transitions
994 when a zone falls back just before DST springs forward.
997 Release 2020d - 2020-10-21 11:24:13 -0700
1000 Palestine ends DST earlier than predicted, on 2020-10-24.
1002 Changes to past and future timestamps
1004 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
1005 as previously predicted (thanks to Sharef Mustafa.) Its
1006 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
1007 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
1008 its spring 2020 transition was on March 28 at 00:00, not March 27
1009 (thanks to Pierre Cashon.) This affects Asia/Gaza and
1010 Asia/Hebron. Assume future spring and fall transitions will be on
1011 the Saturday preceding the last Sunday of March and October,
1015 Release 2020c - 2020-10-16 11:15:53 -0700
1018 Fiji starts DST later than usual, on 2020-12-20.
1020 Changes to future timestamps
1022 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
1023 previously predicted. DST will still end on 2021-01-17.
1024 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
1025 the later-than-usual start date is a one-time departure from the
1028 Changes to build procedure
1030 Rearguard tarballs now contain an empty file pacificnew.
1031 Some older downstream software expects this file to exist.
1032 (Problem reported by Mike Cullinan.)
1035 Release 2020b - 2020-10-06 18:35:04 -0700
1038 Revised predictions for Morocco's changes starting in 2023.
1039 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
1040 Macquarie Island has stayed in sync with Tasmania since 2011.
1041 Casey, Antarctica is at +08 in winter and +11 in summer.
1042 zic no longer supports -y, nor the TYPE field of Rules.
1044 Changes to future timestamps
1046 Morocco's spring-forward after Ramadan is now predicted to occur
1047 no sooner than two days after Ramadan, instead of one day.
1048 (Thanks to Milamber.) The first altered prediction is for 2023,
1049 now predicted to spring-forward on April 30 instead of April 23.
1051 Changes to past and future timestamps
1053 Casey Station, Antarctica has been using +08 in winter and +11 in
1054 summer since 2018. The most recent transition from +08 to +11 was
1055 2020-10-04 00:01. Also, Macquarie Island has been staying in
1056 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
1058 Changes to past and future time zone abbreviations and DST flags
1060 Canada's Yukon, represented by America/Whitehorse and
1061 America/Dawson, changes its time zone rules from -08/-07 to
1062 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
1063 This change affects only the time zone abbreviation (MST vs PDT)
1064 and daylight saving flag for the period between the two dates.
1065 (Thanks to Andrew G. Smith.)
1067 Changes to past timestamps
1069 Correct several transitions for Hungary for 1918/1983.
1070 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
1071 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
1072 time was on 11-01, not 10-01 (thanks to Michael Deckers).
1074 The 1891 French transition was on March 16, not March 15. The
1075 1911-03-11 French transition was at midnight, not a minute later.
1076 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
1077 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
1081 Support for zic's long-obsolete '-y YEARISTYPE' option has been
1082 removed and, with it, so has support for the TYPE field in Rule
1083 lines, which is now reserved for compatibility with earlier zic.
1084 These features were previously deprecated in release 2015f.
1085 (Thanks to Tim Parenti.)
1087 zic now defaults to '-b slim' instead of to '-b fat'.
1089 zic's new '-l -' and '-p -' options uninstall any existing
1090 localtime and posixrules files, respectively.
1092 The undocumented and ineffective tzsetwall function has been
1095 Changes to build procedure
1097 The Makefile now defaults POSIXRULES to '-', so the posixrules
1098 feature (obsolete as of 2019b) is no longer installed by default.
1100 Changes to documentation and commentary
1102 The long-obsolete files pacificnew, systemv, and yearistype.sh have
1103 been removed from the distribution. (Thanks to Tim Parenti.)
1106 Release 2020a - 2020-04-23 16:03:47 -0700
1109 Morocco springs forward on 2020-05-31, not 2020-05-24.
1110 Canada's Yukon advanced to -07 year-round on 2020-03-08.
1111 America/Nuuk renamed from America/Godthab.
1112 zic now supports expiration dates for leap second lists.
1114 Changes to future timestamps
1116 Morocco's second spring-forward transition in 2020 will be May 31,
1117 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
1118 Adjust future-year predictions to use the first Sunday after the
1119 day after Ramadan, not the first Sunday after Ramadan.
1121 Canada's Yukon, represented by America/Whitehorse and
1122 America/Dawson, advanced to -07 year-round, beginning with its
1123 spring-forward transition on 2020-03-08, and will not fall back on
1124 2020-11-01. Although a government press release calls this
1125 "permanent Pacific Daylight Saving Time", we prefer MST for
1126 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
1127 (Thanks to Tim Parenti.)
1129 Changes to past timestamps
1131 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
1133 Changes to timezone identifiers
1135 To reflect current usage in English better, America/Godthab has
1136 been renamed to America/Nuuk. A backwards-compatibility link
1137 remains for the old name.
1141 localtime.c no longer mishandles timestamps after the last
1142 transition in a TZif file with leap seconds and with daylight
1143 saving time transitions projected into the indefinite future.
1144 For example, with TZ='America/Los_Angeles' with leap seconds,
1145 zdump formerly reported a DST transition on 2038-03-14
1146 from 01:59:32.999... to 02:59:33 instead of the correct transition
1147 from 01:59:59.999... to 03:00:00.
1149 zic -L now supports an Expires line in the leapseconds file, and
1150 truncates the TZif output accordingly. This propagates leap
1151 second expiration information into the TZif file, and avoids the
1152 abovementioned localtime.c bug as well as similar bugs present in
1153 many client implementations. If no Expires line is present, zic
1154 -L instead truncates the TZif output based on the #expires comment
1155 present in leapseconds files distributed by tzdb 2018f and later;
1156 however, this usage is obsolescent. For now, the distributed
1157 leapseconds file has an Expires line that is commented out, so
1158 that the file can be fed to older versions of zic which ignore the
1159 commented-out line. Future tzdb distributions are planned to
1160 contain a leapseconds file with an Expires line.
1162 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
1163 set to 1 if the system library supports the feature, and 2 if not.
1164 As before, these macros are nonzero if tzcode should support the
1165 feature, zero otherwise.
1167 The configuration macro ALTZONE now has the same values with the
1168 same meaning as HAVE_TZNAME and USG_COMPAT.
1170 The code's defense against CRLF in leap-seconds.list is now
1171 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
1173 Although the undocumented tzsetwall function is not changed in
1174 this release, it is now deprecated in preparation for removal in
1175 future releases. Due to POSIX requirements, tzsetwall has not
1176 worked for some time. Any code that uses it should instead use
1177 tzalloc(NULL) or, if portability trumps thread-safety, should
1178 unset the TZ environment variable.
1180 Changes to commentary
1182 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
1183 following America/Halifax, and comments about Yukon's "south" and
1184 "north" have been corrected to say "east" and "west". (Thanks to
1188 Release 2019c - 2019-09-11 08:59:48 -0700
1191 Fiji observes DST from 2019-11-10 to 2020-01-12.
1192 Norfolk Island starts observing Australian-style DST.
1194 Changes to future timestamps
1196 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
1197 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
1198 Adjust future guesses accordingly.
1200 Norfolk Island will observe Australian-style DST starting in
1201 spring 2019. The first transition is on 2019-10-06. (Thanks to
1202 Kyle Czech and Michael Deckers.)
1204 Changes to past timestamps
1206 Many corrections to time in Turkey from 1940 through 1985.
1207 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
1209 The Norfolk Island 1975-03-02 transition was at 02:00 standard
1210 time, not 02:00 DST. (Thanks to Michael Deckers.)
1212 South Korea observed DST from 1948 through 1951. Although this
1213 info was supposed to appear in release 2014j, a typo inadvertently
1214 suppressed the change. (Thanks to Alois Treindl.)
1216 Detroit observed DST in 1967 and 1968 following the US DST rules,
1217 except that its 1967 DST began on June 14 at 00:01. (Thanks to
1218 Alois Treindl for pointing out that the old data entries were
1221 Fix several errors in pre-1970 transitions in Perry County, IN.
1222 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
1224 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
1225 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
1226 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
1227 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
1228 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
1229 Königsberg switched to +03 on 04-07 not 01-01.
1231 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
1232 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
1233 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
1235 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
1236 (Thanks to Michael Deckers.)
1238 Changes to past time zone abbreviations and DST flags
1240 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
1241 is now flagged as DST and is abbreviated HKWT not HKT.
1245 leapseconds.awk now relies only on its input data, rather than
1246 also relying on its comments. (Inspired by code from Dennis
1247 Ferguson and Chris Woodbury.)
1249 The code now defends against CRLFs in leap-seconds.list.
1250 (Thanks to Brian Inglis and Chris Woodbury.)
1252 Changes to documentation and commentary
1254 theory.html discusses leap seconds. (Thanks to Steve Summit.)
1256 Nashville's newspapers dueled about the time of day in the 1950s.
1257 (Thanks to John Seigenthaler.)
1259 Liechtenstein observed Swiss DST in 1941/2.
1260 (Thanks to Alois Treindl.)
1263 Release 2019b - 2019-07-01 00:09:53 -0700
1266 Brazil no longer observes DST.
1267 'zic -b slim' outputs smaller TZif files; please try it out.
1268 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
1270 Changes to future timestamps
1272 Brazil has canceled DST and will stay on standard time indefinitely.
1273 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
1276 Predictions for Morocco now go through 2087 instead of 2037, to
1277 work around a problem on newlib when using TZif files output by
1278 zic 2019a or earlier. (Problem reported by David Gauchard.)
1280 Changes to past and future timestamps
1282 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
1283 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
1284 future transitions to be March's last Friday at 00:00.
1286 Changes to past timestamps
1288 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
1289 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
1290 not 09-15 at 00:00. In 1946 its spring-forward transition was on
1291 04-21 at 00:00, not the previous day at 03:30. From 1946 through
1292 1952 its fall-back transitions occurred at 04:30, not at 03:30.
1293 In 1947 its fall-back transition was on 11-30, not 12-30.
1296 Changes to past time zone abbreviations
1298 Italy's 1866 transition to Rome Mean Time was on December 12, not
1299 September 22. This affects only the time zone abbreviation for
1300 Europe/Rome between those dates. (Thanks to Stephen Trainor and
1303 Changes affecting metadata only
1305 Add info about the Crimea situation in zone1970.tab and zone.tab.
1306 (Problem reported by Serhii Demediuk.)
1310 zic's new -b option supports a way to control data bloat and to
1311 test for year-2038 bugs in software that reads TZif files.
1312 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
1313 for example, changing from fat to slim shrinks the Europe/London
1314 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
1315 files represent the same set of timestamps and use the same TZif
1316 format as documented in tzfile(5) and in Internet RFC 8536.
1317 Fat format attempts to work around bugs or incompatibilities in
1318 older software, notably software that mishandles 64-bit TZif data
1319 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
1320 Slim format is more efficient and does not work around 64-bit bugs
1321 or obsolete TZ strings. Currently zic defaults to fat format
1322 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
1323 out-of-the-box default is intended to change in future releases
1324 as the buggy software often mishandles timestamps anyway.
1326 zic no longer treats a set of rules ending in 2037 specially.
1327 Previously, zic assumed that such a ruleset meant that future
1328 timestamps could not be predicted, and therefore omitted a
1329 POSIX-like TZ string in the TZif output. The old behavior is no
1330 longer needed for current tzdata, and caused problems with newlib
1331 when used with older tzdata (reported by David Gauchard).
1333 zic no longer generates some artifact transitions. For example,
1334 Europe/London no longer has a no-op transition in January 1996.
1336 Changes to build procedure
1338 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
1341 Changes to documentation and commentary
1343 The Makefile now documents the POSIXRULES macro as being obsolete,
1344 and similarly, zic's -p POSIXRULES option is now documented as
1345 being obsolete. Although the POSIXRULES feature still exists and
1346 works as before, in practice it is rarely used for its intended
1347 purpose, and it does not work either in the default reference
1348 implementation (for timestamps after 2037) or in common
1349 implementations such as GNU/Linux (for contemporary timestamps).
1350 Since POSIXRULES was designed primarily as a temporary transition
1351 facility for System V platforms that died off decades ago, it is
1352 being decommissioned rather than institutionalized.
1354 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
1357 Release 2019a - 2019-03-25 22:01:33 -0700
1360 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
1361 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
1363 Changes to past and future timestamps
1365 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
1366 previously predicted. Adjust our prediction by guessing that spring
1367 transitions will be between 24 and 30 March, which matches recent practice
1368 since 2016. (Thanks to Even Scharning and Tim Parenti.)
1370 Metlakatla ended its observance of Pacific standard time,
1371 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
1372 Stanley and Tim Parenti.)
1374 Changes to past timestamps
1376 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
1377 (Thanks to Alois Treindl and Isaac Starkman.)
1379 Changes to time zone abbreviations
1381 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
1382 of being a separate zone that generates the abbreviation "UCT",
1383 which nowadays is typically a typo. (Problem reported by Isiah
1388 zic now has an -r option to limit the time range of output data.
1389 For example, 'zic -r @1000000000' limits the output data to
1390 timestamps starting 1000000000 seconds after the Epoch.
1391 This helps shrink output size and can be useful for applications
1392 not needing the full timestamp history, such as TZDIST truncation;
1393 see Internet RFC 8536 section 5.1. (Inspired by a feature request
1394 from Christopher Wong, helped along by bug reports from Wong and
1397 Changes to documentation
1399 Mention Internet RFC 8536 (February 2019), which documents TZif.
1401 tz-link.html now cites tzdata-meta
1402 <https://tzdata-meta.timtimeonline.com/>.
1405 Release 2018i - 2018-12-30 11:05:43 -0800
1408 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
1410 Changes to future timestamps
1412 Due to a change in government, São Tomé and Príncipe switches back
1413 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
1414 Nasardinov and Michael Deckers.)
1417 Release 2018h - 2018-12-23 17:59:32 -0800
1420 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
1421 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
1422 Metlakatla, Alaska observes PST this winter only.
1423 Guess Morocco will continue to adjust clocks around Ramadan.
1424 Add predictions for Iran from 2038 through 2090.
1426 Changes to future timestamps
1428 Guess that Morocco will continue to fall back just before and
1429 spring forward just after Ramadan, the practice since 2012.
1430 (Thanks to Maamar Abdelkader.) This means Morocco will observe
1431 negative DST during Ramadan in main and vanguard formats, and in
1432 rearguard format it stays in the +00 timezone and observes
1433 ordinary DST in all months other than Ramadan. As before, extend
1434 this guesswork to the year 2037. As a consequence, Morocco is
1435 scheduled to observe three DST transitions in some Gregorian years
1436 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
1439 The table of exact transitions for Iranian DST has been extended.
1440 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
1441 It now cuts off before 2091 as there is doubt about how the Persian
1442 calendar will treat 2091. This change predicts DST transitions in
1443 2038-9, 2042-3, and 2046-7 to occur one day later than previously
1444 predicted. As before, post-cutoff transitions are approximated.
1446 Changes to past and future timestamps
1448 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
1449 +05 on 2018-12-21. This is a zone split as Qostanay (aka
1450 Kostanay) did not switch, so create a zone Asia/Qostanay.
1452 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
1453 It did not change clocks that day and remains on -08 this winter.
1454 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
1455 rules next spring, so this change affects only timestamps
1456 from 2018-11-04 through 2019-03-10.
1458 Change to past timestamps
1460 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
1461 not 00:00. I transcribed the time incorrectly from Shanks.
1462 (Thanks to Phake Nick.)
1464 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
1465 (Thanks to Phake Nick.)
1467 Guam observed DST irregularly from 1959 through 1977.
1468 (Thanks to Phake Nick.)
1470 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
1471 10-01 changed standard time to +08:30 (not +08). Its transition
1472 back to +08 after WWII was on 1945-09-15, not the previous day.
1473 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
1474 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1475 its 1952 fallback was on 11-02 (not 10-25).
1477 This release contains many changes to timestamps before 1946 due
1478 to Japanese possession or occupation of Pacific/Chuuk,
1479 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1480 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1481 (Thanks to Phake Nick.)
1483 Assume that the Spanish East Indies was like the Philippines and
1484 observed American time until the end of 1844. This affects
1485 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1487 Changes to past tm_isdst flags
1489 For the recent Morocco change, the tm_isdst flag should be 1 from
1490 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1491 Give a URL to the official decree. (Thanks to Matt Johnson.)
1494 Release 2018g - 2018-10-26 22:22:45 -0700
1497 Morocco switches to permanent +01 on 2018-10-28.
1499 Changes to future timestamps
1501 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1502 so its clocks will not fall back as previously scheduled.
1503 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1507 When generating TZif files with leap seconds, zic no longer uses a
1508 format that trips up older 32-bit clients, fixing a bug introduced
1509 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1510 for QTBUG-53071 now also works for TZif files with leap seconds.
1512 The translator to rearguard format now rewrites the line
1513 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1514 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1515 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1516 and earlier. (Reported by Christos Zoulas.)
1518 Changes to past time zone abbreviations
1520 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1521 This reverts to 2011h, as the abbreviation change in 2011i was
1524 Changes to documentation
1526 tzfile.5 has new sections on interoperability issues.
1529 Release 2018f - 2018-10-18 00:14:18 -0700
1532 Volgograd moves from +03 to +04 on 2018-10-28.
1533 Fiji ends DST 2019-01-13, not 2019-01-20.
1534 Most of Chile changes DST dates, effective 2019-04-06.
1536 Changes to future timestamps
1538 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1539 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1541 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1542 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1545 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1546 time, and resume DST on the first Saturday in September at 24:00 mainland
1547 time. The changes are effective from 2019-04-06, and do not affect the
1548 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1549 and Tim Parenti.) Adjust future predictions accordingly.
1551 Changes to past timestamps
1553 The 2018-05-05 North Korea 30-minute time zone change took place
1554 at 23:30 the previous day, not at 00:00 that day.
1556 China's 1988 spring-forward transition was on April 17, not
1557 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1560 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1561 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1562 temporarily switched to +09/+10 during World War II. Macau
1563 observed DST in 1942/79, not 1961/80, and there were several
1564 errors for transition times and dates. (Thanks to P Chan.)
1566 The 1948-1951 fallback transitions in Japan were at 25:00 on
1567 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1568 zic turns this into 01:00 on the day after September's second
1569 Saturday, which is the best that POSIX or C platforms can do.
1571 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1572 paper by Li Yu, replacing more-questionable data from Shanks.
1574 Changes to time zone abbreviations
1576 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1580 zic now always generates TZif files where time type 0 is used for
1581 timestamps before the first transition. This simplifies the
1582 reading of TZif files and should not affect behavior of existing
1583 TZif readers because the same set of time types is used; only
1584 their internal indexes may have changed. This affects only the
1585 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1586 EET, which previously used nonzero types for these timestamps.
1588 Because of the type 0 change, zic no longer outputs a dummy
1589 transition at time -2**59 (before the Big Bang), as clients should
1590 no longer need this to handle historical timestamps correctly.
1591 This reverts a change introduced in 2013d and shrinks most TZif
1592 files by a few bytes.
1594 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1595 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1596 occurs at 18:00 on the Saturday before the last Sunday in April.
1597 This behavior was documented in 2018a but the code did not
1598 entirely match the documentation.
1600 localtime.c no longer requires at least one time type in TZif
1601 files that lack transitions or have a POSIX-style TZ string. This
1602 future-proofs the code against possible future extensions to the
1603 format that would allow TZif files with POSIX-style TZ strings and
1604 without transitions or time types.
1606 A read-access subscript error in localtime.c has been fixed.
1607 It could occur only in TZif files with timecnt == 0, something that
1608 does not happen in practice now but could happen in future versions.
1610 localtime.c no longer ignores TZif POSIX-style TZ strings that
1611 specify only standard time. Instead, these TZ strings now
1612 override the default time type for timestamps after the last
1613 transition (or for all timestamps if there are no transitions),
1614 just as DST strings specifying DST have always done.
1616 leapseconds.awk now outputs "#updated" and "#expires" comments,
1617 and supports leap seconds at the ends of months other than June
1618 and December. (Inspired by suggestions from Chris Woodbury.)
1620 Changes to documentation
1622 New restrictions: A Rule name must start with a character that
1623 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1624 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1625 The latter restriction makes room for future extensions (a
1626 possibility noted by Tom Lane).
1628 tzfile.5 now documents what time types apply before the first and
1629 after the last transition, if any.
1631 Documentation now uses the spelling "timezone" for a TZ setting
1632 that determines timestamp history, and "time zone" for a
1633 geographic region currently sharing the same standard time.
1635 The name "TZif" is now used for the tz binary data format.
1637 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1638 (Thanks to Aldrin Martoq for the link.)
1640 Changes to build procedure
1642 New 'make' target 'rearguard_tarballs' to build the rearguard
1643 tarball only. This is a convenience on platforms that lack lzip
1644 if you want to build the rearguard tarball. (Problem reported by
1647 tzdata.zi is now more stable from release to release. (Problem
1648 noted by Tom Lane.) It is also a bit shorter.
1650 tzdata.zi now can contain comment lines documenting configuration
1651 information, such as which data format was selected, which input
1652 files were used, and how leap seconds are treated. (Problems
1653 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1654 are used these comment lines are absent, for backward
1655 compatibility. A redistributor intending to alter its copy of the
1656 files should also append "-LABEL" to the 'version' file's first
1657 line, where "LABEL" identifies the redistributor's change.
1660 Release 2018e - 2018-05-01 23:42:51 -0700
1664 North Korea switches back to +09 on 2018-05-05.
1665 The main format uses negative DST again, for Ireland etc.
1666 'make tarballs' now also builds a rearguard tarball.
1667 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1669 Changes to past and future timestamps
1671 North Korea switches back from +0830 to +09 on 2018-05-05.
1672 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1675 Bring back the negative-DST changes of 2018a, except be more
1676 compatible with data parsers that do not support negative DST.
1677 Also, this now affects historical timestamps in Namibia and the
1678 former Czechoslovakia, not just Ireland. The main format now uses
1679 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1680 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1681 does not affect UT offsets, only time zone abbreviations and the
1682 tm_isdst flag. Also, this does not affect rearguard or vanguard
1683 formats; effectively the main format now uses vanguard instead of
1684 rearguard format. Data parsers that do not support negative DST
1685 can still use data from the rearguard tarball described below.
1687 Changes to build procedure
1689 The command 'make tarballs' now also builds the tarball
1690 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1691 except that it uses rearguard format intended for trailing-edge
1694 Changes to data format and to code
1696 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1697 suffix, which specifies whether the adjusted time is standard time
1698 or daylight saving time. If no suffix is given, daylight saving
1699 time is used if and only if the SAVE column is nonzero; this is
1700 the longstanding behavior. Although this new feature is not used
1701 in tzdata, it could be used to specify the legal time in Namibia
1702 1994-2017, as opposed to the popular time (see below).
1704 Changes to past timestamps
1706 From 1994 through 2017 Namibia observed DST in winter, not summer.
1707 That is, it used negative DST, as Ireland still does. This change
1708 does not affect UTC offsets; it affects only the tm_isdst flag and
1709 the abbreviation used during summer, which is now CAT, not WAST.
1710 Although (as noted by Michael Deckers) summer and winter time were
1711 both simply called "standard time" in Namibian law, in common
1712 practice winter time was considered to be DST (as noted by Stephen
1713 Colebourne). The full effect of this change is only in vanguard
1714 and main format; in rearguard format, the tm_isdst flag is still
1715 zero in winter and nonzero in summer.
1717 In 1946/7 Czechoslovakia also observed negative DST in winter.
1718 The full effect of this change is only in vanguard and main
1719 formats; in rearguard format, it is modeled as plain GMT without
1720 daylight saving. Also, the dates of some 1944/5 DST transitions
1721 in Czechoslovakia have been changed.
1724 Release 2018d - 2018-03-22 07:05:46 -0700
1728 Palestine starts DST a week earlier in 2018.
1729 Add support for vanguard and rearguard data consumers.
1730 Add subsecond precision to source data format, though not to data.
1732 Changes to future timestamps
1734 In 2018, Palestine starts DST on March 24, not March 31.
1735 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1737 Changes to past and future timestamps
1739 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1740 at 04:00. (Thanks to Steffen Thorsen.)
1742 Changes to past timestamps
1744 Historical transitions for Uruguay, represented by
1745 America/Montevideo, have been updated per official legal documents,
1746 replacing previous data mainly originating from the inventions of
1747 Shanks & Pottenger. This has resulted in adjustments ranging from
1748 30 to 90 minutes in either direction over at least two dozen
1749 distinct periods ranging from one day to several years in length.
1750 A mere handful of pre-1991 transitions are unaffected; data since
1751 then has come from more reliable contemporaneous reporting. These
1752 changes affect various timestamps in 1920-1923, 1936, 1939,
1753 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1754 Additionally, Uruguay's pre-standard-time UT offset has been
1755 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1756 match the location of the Observatory of the National Meteorological
1757 Institute in Montevideo.
1758 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1760 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1761 (Thanks to Kerry Shetline.)
1763 Fix the 1912-01-01 transition for Portugal and its colonies.
1764 This transition was at 00:00 according to the new UT offset, not
1765 according to the old one. Also assume that Cape Verde switched on
1766 the same date as the rest, not in 1907. This affects
1767 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1768 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1769 (Thanks to Michael Deckers.)
1771 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1774 Changes to past time zone abbreviations
1776 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1777 is no clock change associated with the transition.
1779 Changes to build procedure
1781 The new DATAFORM macro in the Makefile lets the installer choose
1782 among three source data formats. The idea is to lessen downstream
1783 disruption when data formats are improved.
1785 * DATAFORM=vanguard installs from the latest, bleeding-edge
1786 format. DATAFORM=main (the default) installs from the format
1787 used in the 'africa' etc. files. DATAFORM=rearguard installs
1788 from a trailing-edge format. Eventually, elements of today's
1789 vanguard format should move to the main format, and similarly
1790 the main format's features should eventually move to the
1793 * In the current version, the main and rearguard formats are
1794 identical and match that of 2018c, so this change does not
1795 affect default behavior. The vanguard format currently contains
1796 one feature not in the main format: negative SAVE values. This
1797 improves support for Ireland, which uses Irish Standard Time
1798 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1799 supported negative SAVE values for decades, and this feature
1800 should move to the main format soon. However, it will not move
1801 to the rearguard format for quite some time because some
1802 downstream parsers do not support it.
1804 * The build procedure constructs three files vanguard.zi, main.zi,
1805 and rearguard.zi, one for each format. Although the files
1806 represent essentially the same data, they may have minor
1807 discrepancies that users are not likely to notice. The files
1808 are intended for downstream data consumers and are not
1809 installed. Zoneinfo parsers that do not support negative SAVE values
1810 should start using rearguard.zi, so that they will be unaffected
1811 when the negative-DST feature moves from vanguard to main.
1812 Bleeding-edge Zoneinfo parsers that support the new features
1813 already can use vanguard.zi; in this respect, current tzcode is
1816 The Makefile should now be safe for parallelized builds, and 'make
1817 -j to2050new.tzs' is now much faster on a multiprocessor host
1820 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1821 prepends TZDIR/ to file names that do not begin with '/'. This is
1822 not recommended for general use, due to its security implications.
1823 (From a suggestion by Manuela Friedrich.)
1827 zic now accepts subsecond precision in expressions like
1828 00:19:32.13, which is approximately the legal time of the
1829 Netherlands from 1835 to 1937. However, because it is
1830 questionable whether the few recorded uses of non-integer offsets
1831 had subsecond precision in practice, there are no plans for tzdata
1832 to use this feature. (Thanks to Steve Allen for pointing out
1833 the limitations of historical data in this area.)
1835 The code is a bit more portable to MS-Windows. Installers can
1836 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1837 reserve identifiers like 'localtime'. (Thanks to Manuela
1840 Changes to documentation and commentary
1842 theory.html now outlines tzdb's extensions to POSIX's model for
1843 civil time, and has a section "POSIX features no longer needed"
1844 that lists POSIX API components that are now vestigial.
1845 (From suggestions by Steve Summit.) It also better distinguishes
1846 time zones from tz regions. (From a suggestion by Guy Harris.)
1848 Commentary is now more consistent about using the phrase "daylight
1849 saving time", to match the C name tm_isdst. Daylight saving time
1850 need not occur in summer, and need not have a positive offset from
1853 Commentary about historical transitions in Uruguay has been expanded
1854 with links to many relevant legal documents.
1855 (Thanks to Tim Parenti.)
1857 Commentary now uses some non-ASCII characters with Unicode value
1858 less than U+0100, as they can be useful and should work even with
1859 older editors such as XEmacs.
1862 Release 2018c - 2018-01-22 23:00:44 -0800
1865 Revert Irish changes that relied on negative SAVE values.
1869 Revert the 2018a change to Europe/Dublin. As before, this change
1870 does not affect UT offsets or abbreviations; it affects only
1871 whether timestamps are considered to be standard time or
1872 daylight-saving time, as expressed in the tm_isdst flag of C's
1873 struct tm type. This reversion is intended to be a temporary
1874 workaround for problems discovered with downstream uses of
1875 releases 2018a and 2018b, which implemented Irish time by using
1876 negative SAVE values in the Eire rules of the 'europe' file.
1877 Although negative SAVE values have been part of tzcode for many
1878 years and are supported by many platforms, they were not
1879 documented before 2018a and ICU and OpenJDK do not currently
1880 support them. A mechanism to export data to platforms lacking
1881 support for negative DST is planned to be developed before the
1882 change is reapplied. (Problems reported by Deborah Goldsmith and
1883 Stephen Colebourne.)
1885 Changes to past timestamps
1887 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1888 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1890 Changes to build procedure
1892 The build procedure now works around mawk 1.3.3's lack of support
1893 for character class expressions. (Problem reported by Ohyama.)
1896 Release 2018b - 2018-01-17 23:24:48 -0800
1899 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1901 Changes to build procedure
1903 The distribution now contains the file 'pacificnew' again.
1904 This file was inadvertently omitted in the 2018a distribution.
1905 (Problem reported by Matias Fonzo.)
1908 Release 2018a - 2018-01-12 22:29:21 -0800
1911 São Tomé and Príncipe switched from +00 to +01.
1912 Brazil's DST will now start on November's first Sunday.
1913 Ireland's standard time is now in the summer, not the winter.
1914 Use Debian-style installation locations, instead of 4.3BSD-style.
1917 Changes to past and future timestamps
1919 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1920 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1922 Changes to future timestamps
1924 Starting in 2018 southern Brazil will begin DST on November's
1925 first Sunday instead of October's third Sunday. (Thanks to
1928 Changes to past timestamps
1930 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1931 been corrected. The 'backzone' and 'zone.tab' files did not agree
1932 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1935 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1936 BST instead of BOST, to be more consistent with the convention
1937 used for Latvian Summer Time (1918-9) and for British Summer Time.
1941 Change Europe/Dublin so that it observes Irish Standard Time (UT
1942 +01) in summer and GMT (as negative daylight-saving) in winter,
1943 instead of observing standard time (GMT) in winter and Irish
1944 Summer Time (UT +01) in summer. This change does not affect UT
1945 offsets or abbreviations; it affects only whether timestamps are
1946 considered to be standard time or daylight-saving time, as
1947 expressed in the tm_isdst flag of C's struct tm type.
1948 (Discrepancy noted by Derick Rethans.)
1950 Changes to build procedure
1952 The default installation locations have been changed to mostly
1953 match Debian circa 2017, instead of being designed as an add-on to
1954 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1955 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1956 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1957 locations more precisely. (This responds to suggestions from
1958 Brian Inglis and from Steve Summit.)
1960 The default installation procedure no longer creates the
1961 backward-compatibility link US/Pacific-New, which causes
1962 confusion during user setup (e.g., see Debian bug 815200).
1963 Use 'make BACKWARD="backward pacificnew"' to create the link
1964 anyway, for now. Eventually we plan to remove the link entirely.
1966 tzdata.zi now contains a version-number comment.
1967 (Suggested by Tom Lane.)
1969 The Makefile now quotes values like BACKWARD more carefully when
1970 passing them to the shell. (Problem reported by Zefram.)
1972 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1973 that have snprintf and use pre-C99 compilers. (Problem reported
1978 zic has a new option -t FILE that specifies the location of the
1979 file that determines local time when TZ is unset. The default for
1980 this location can be configured via the new TZDEFAULT makefile
1981 macro, which defaults to /etc/localtime.
1983 Diagnostics and commentary now distinguish UT from UTC more
1984 carefully; see theory.html for more information about UT vs UTC.
1986 zic has been ported to GCC 8's -Wstringop-truncation option.
1987 (Problem reported by Martin Sebor.)
1989 Changes to documentation and commentary
1991 The zic man page now documents the longstanding behavior that
1992 times and years can be out of the usual range, with negative times
1993 counting backwards from midnight and with year 0 preceding year 1.
1994 (Problem reported by Michael Deckers.)
1996 The theory.html file now mentions the POSIX limit of six chars
1997 per abbreviation, and lists alphabetic abbreviations used.
1999 The files tz-art.htm and tz-link.htm have been renamed to
2000 tz-art.html and tz-link.html, respectively, for consistency with
2001 other file names and to simplify web server configuration.
2004 Release 2017c - 2017-10-20 14:49:34 -0700
2007 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
2008 Fiji ends DST 2018-01-14, not 2018-01-21.
2009 Namibia switches from +01/+02 to +02 on 2018-04-01.
2010 Sudan switches from +03 to +02 on 2017-11-01.
2011 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
2012 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
2013 A new file tzdata.zi now holds a small text copy of all data.
2014 The zic input format has been regularized slightly.
2016 Changes to future timestamps
2018 Northern Cyprus has decided to resume EU rules starting
2019 2017-10-29, thus reinstituting winter time.
2021 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
2022 predicted. (Thanks to Dominic Fok.) Adjust future predictions
2025 Namibia will switch from +01 with DST to +02 all year on
2026 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
2027 at 02:00. (Thanks to Steffen Thorsen.)
2029 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
2030 Atyya and Yahia Abdalla.) South Sudan is not switching, so
2031 Africa/Juba is no longer a link to Africa/Khartoum.
2033 Tonga has likely ended its experiment with DST, and will not
2034 adjust its clocks on 2017-11-05. Although Tonga has not announced
2035 whether it will continue to observe DST, the IATA is assuming that
2036 it will not. (Thanks to David Wade.)
2038 Turks & Caicos will switch from -04 all year to -05 with US DST on
2039 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
2040 at 02:00. (Thanks to Steffen Thorsen.)
2042 Changes to past timestamps
2044 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
2045 (Thanks to Arthur David Olson.)
2047 Detroit did not observe DST in 1967.
2049 Use railway time for Asia/Kolkata before 1941, by switching to
2050 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
2051 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
2053 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
2054 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
2056 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
2057 American time in 1892, not 1879. (Thanks to Michael Deckers.)
2059 Adjust the 1867 transition in Alaska to better reflect the
2060 historical record, by changing it to occur on 1867-10-18 at 15:30
2061 Sitka time rather than at the start of 1867-10-17 local time.
2062 Although strictly speaking this is accurate only for Sitka,
2063 the rest of Alaska's blanks need to be filled in somehow.
2065 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
2066 (Thanks to Michael Deckers.)
2068 Add 7 s to the UT offset in Asia/Yangon before 1920.
2070 Changes to zone names
2072 Remove Canada/East-Saskatchewan from the 'backward' file, as it
2073 exceeded the 14-character limit and was an unused misnomer anyway.
2075 Changes to build procedure
2077 To support applications that prefer to read time zone data in text
2078 form, two zic input files tzdata.zi and leapseconds are now
2079 installed by default. The commands 'zic tzdata.zi' and 'zic -L
2080 leapseconds tzdata.zi' can reproduce the tzdata binary files
2081 without and with leap seconds, respectively. To prevent these two
2082 new files from being installed, use 'make TZDATA_TEXT=', and to
2083 suppress leap seconds from the tzdata text installation, use 'make
2084 TZDATA_TEXT=tzdata.zi'.
2086 'make BACKWARD=' now suppresses backward-compatibility names
2087 like 'US/Pacific' that are defined in the 'backward' and
2090 'make check' now works on systems that lack a UTF-8 locale,
2091 or that lack the nsgmls program. Set UTF8_LOCALE to configure
2092 the name of a UTF-8 locale, if you have one.
2094 Y2K runtime checks are no longer enabled by default. Add
2095 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
2096 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
2097 to disable them. (New name suggested by Brian Inglis.)
2099 The build procedure for zdump now works on AIX 7.1.
2100 (Problem reported by Kees Dekker.)
2104 zic and the reference runtime now reject multiple leap seconds
2105 within 28 days of each other, or leap seconds before the Epoch.
2106 As a result, support for double leap seconds, which was
2107 obsolescent and undocumented, has been removed. Double leap
2108 seconds were an error in the C89 standard; they have never existed
2109 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
2110 noticing glitches in the code that uncovered this problem.)
2112 zic now warns about use of the obsolescent and undocumented -y
2113 option, and about use of the obsolescent TYPE field of Rule lines.
2115 zic now allows unambiguous abbreviations like "Sa" and "Su" for
2116 weekdays; formerly it rejected them due to a bug. Conversely, zic
2117 no longer considers non-prefixes to be abbreviations; for example,
2118 it no longer accepts "lF" as an abbreviation for "lastFriday".
2119 Also, zic warns about the undocumented usage with a "last-"
2120 prefix, e.g., "last-Fri".
2122 Similarly, zic now accepts the unambiguous abbreviation "L" for
2123 "Link" in ordinary context and for "Leap" in leap-second context.
2124 Conversely, zic no longer accepts non-prefixes such as "La" as
2125 abbreviations for words like "Leap".
2127 zic no longer accepts leap second lines in ordinary input, or
2128 ordinary lines in leap second input. Formerly, zic sometimes
2129 warned about this undocumented usage and handled it incorrectly.
2131 The new macro HAVE_TZNAME governs whether the tzname external
2132 variable is exported, instead of USG_COMPAT. USG_COMPAT now
2133 governs only the external variables "timezone" and "daylight".
2134 This change is needed because the three variables are not in the
2135 same category: although POSIX requires tzname, it specifies the
2136 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
2137 if not defined, the code attempts to guess it from other macros.
2139 localtime.c and difftime.c no longer require stdio.h, and .c files
2140 other than zic.c no longer require sys/wait.h.
2142 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
2144 Calculation of time_t extrema works around a bug in GCC 4.8.4
2145 (Reported by Stan Shebs and Joseph Myers.)
2147 zic.c no longer mistranslates formats of line numbers in non-English
2148 locales. (Problem reported by Benno Schulenberg.)
2150 Several minor changes have been made to the code to make it a
2151 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
2152 Dekker for reporting the problems.)
2154 Changes to documentation and commentary
2156 The two new files 'theory.html' and 'calendars' contain the
2157 contents of the removed file 'Theory'. The goal is to document
2158 tzdb theory more accessibly.
2160 The zic man page now documents abbreviation rules.
2162 tz-link.htm now covers how to apply tzdata changes to clients.
2163 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
2165 The leap-seconds.list URL has been updated to something that is
2166 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
2168 Release 2017b - 2017-03-17 07:30:38 -0700
2170 Briefly: Haiti has resumed DST.
2172 Changes to past and future timestamps
2174 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
2176 Changes to past timestamps
2178 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
2180 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
2181 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
2185 The reference localtime implementation now falls back on the
2186 current US daylight-saving transition rules rather than the
2187 1987-2006 rules. This fallback occurs only when (1) the TZ
2188 environment variable has a value like "AST4ADT" that asks
2189 for daylight saving time but does not specify the rules, (2) there
2190 is no file by that name, and (3) the TZDEFRULES file cannot be
2191 loaded. (Thanks to Tom Lane.)
2194 Release 2017a - 2017-02-28 00:05:36 -0800
2196 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
2199 Changes to future timestamps
2201 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
2203 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
2204 Its clocks diverge from America/Santiago starting 2017-05-13 at
2205 23:00, hiving off a new zone America/Punta_Arenas. Although the
2206 Chilean government says this change expires in May 2019, for now
2207 assume it's permanent. (Thanks to Juan Correa and Deborah
2208 Goldsmith.) This also affects Antarctica/Palmer.
2210 Changes to past timestamps
2212 Fix many entries for historical timestamps for Europe/Madrid
2213 before 1979, to agree with tables compiled by Pere Planesas of the
2214 National Astronomical Observatory of Spain. As a side effect,
2215 this changes some timestamps for Africa/Ceuta before 1929, which
2216 are probably guesswork anyway. (Thanks to Steve Allen and
2217 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
2218 correcting the 1901 transition.)
2220 Ecuador observed DST from 1992-11-28 to 1993-02-05.
2221 (Thanks to Alois Treindl.)
2223 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
2224 (Thanks to Stepan Golosunov.)
2226 Changes to past and future time zone abbreviations
2228 Switch to numeric time zone abbreviations for South America, as
2229 part of the ongoing project of removing invented abbreviations.
2230 This avoids the need to invent an abbreviation for the new Chilean
2231 new zone. Similarly, switch from invented to numeric time zone
2232 abbreviations for Afghanistan, American Samoa, the Azores,
2233 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
2234 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
2235 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
2236 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
2237 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
2238 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
2239 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
2240 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
2241 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
2242 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
2243 for half-hour daylight saving time in Belize before 1944 and in
2244 the Dominican Republic before 1975; and for Canary Islands before
2245 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
2246 Indian Summer Time before 1942, for Indonesia before around 1964,
2247 for Kenya before 1960, for Liberia before 1973, for Madeira before
2248 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
2249 Pakistan before 1971, for Western Sahara before 1977, and for
2250 Zaporozhye in 1880-1924.
2252 For Alaska time from 1900 through 1967, instead of "CAT" use the
2253 abbreviation "AST", the abbreviation commonly used at the time
2254 (Atlantic Standard Time had not been standardized yet). Use "AWT"
2255 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
2257 Use "CST" and "CDT" instead of invented abbreviations for Macau
2258 before 1999 and Taiwan before 1938, and use "JST" instead of the
2259 invented abbreviation "JCST" for Japan and Korea before 1938.
2261 Change to database entry category
2263 Move the Pacific/Johnston link from 'australasia' to 'backward',
2264 since Johnston is now uninhabited.
2268 zic no longer mishandles some transitions in January 2038 when it
2269 attempts to work around Qt bug 53071. This fixes a bug affecting
2270 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
2271 now contains a workaround, useful when loading a file generated by
2272 a buggy zic. (Problem and localtime.c fix reported by Bradley
2275 zdump -i now outputs non-hour numeric time zone abbreviations
2276 without a colon, e.g., "+0530" rather than "+05:30". This agrees
2277 with zic %z and with common practice, and simplifies auditing of
2280 zdump is now buildable again with -DUSE_LTZ=0.
2281 (Problem reported by Joseph Myers.)
2283 zdump.c now always includes private.h, to avoid code duplication
2284 with private.h. (Problem reported by Kees Dekker.)
2286 localtime.c no longer mishandles early or late timestamps
2287 when TZ is set to a POSIX-style string that specifies DST.
2288 (Problem reported by Kees Dekker.)
2290 date and strftime now cause %z to generate "-0000" instead of
2291 "+0000" when the UT offset is zero and the time zone abbreviation
2294 Changes to documentation and commentary
2296 The 'Theory' file now better documents choice of historical time
2297 zone abbreviations. (Problems reported by Michael Deckers.)
2299 tz-link.htm now covers leap smearing, which is popular in clouds.
2302 Release 2016j - 2016-11-22 23:17:13 -0800
2304 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
2306 Changes to future timestamps
2308 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
2309 This hives off a new zone Europe/Saratov from Europe/Volgograd.
2310 (Thanks to Yuri Konotopov and Stepan Golosunov.)
2312 Changes to past timestamps
2314 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
2315 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
2316 1999, not fall 1994. (Thanks to Stepan Golosunov.)
2318 Changes to past time zone abbreviations
2320 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
2321 summer time before 1948. The old use of "EET" was a typo.
2325 zic no longer mishandles file systems that lack hard links, fixing
2326 bugs introduced in 2016g. (Problems reported by Tom Lane.)
2327 Also, when the destination already contains symbolic links, zic
2328 should now work better on systems where the 'link' system call
2329 does not follow symbolic links.
2331 Changes to documentation and commentary
2333 tz-link.htm now documents the relationship between release version
2334 numbers and development-repository commit tags. (Suggested by
2337 The 'Theory' file now documents UT.
2339 iso3166.tab now accents "Curaçao", and commentary now mentions
2340 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
2343 Release 2016i - 2016-11-01 23:19:52 -0700
2345 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
2346 reintroduces DST on 2016-11-06.
2348 Changes to future timestamps
2350 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
2351 2017-01-15 at 03:00. Assume future observances in Tonga will be
2352 from the first Sunday in November through the third Sunday in
2353 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
2354 time zone abbreviations for this zone.
2356 Changes to past and future timestamps
2358 Northern Cyprus is now +03 year round, causing a split in Cyprus
2359 time zones starting 2016-10-30 at 04:00. This creates a zone
2360 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
2362 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
2363 (Thanks to Steffen Thorsen.)
2365 Changes to past timestamps
2367 Several corrections were made for pre-1975 timestamps in Italy.
2368 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
2371 First, the 1893-11-01 00:00 transition in Italy used the new UT
2372 offset (+01), not the old (+00:49:56). (Thanks to Michael
2375 Second, rules for daylight saving in Italy were changed to agree
2376 with Italy's National Institute of Metrological Research (INRiM)
2377 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
2378 Inglis, and Michael Deckers):
2380 The 1916-06-03 transition was at 24:00, not 00:00.
2382 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
2385 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
2388 The 1944-09-17 transition was at 03:00, not 01:00. This
2389 particular change is taken from Italian law as INRiM's table,
2390 (which says 02:00) appears to have a typo here. Also, keep the
2391 1944-04-03 transition for Europe/Rome, as Rome was controlled by
2394 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
2399 The code should now be buildable on AmigaOS merely by setting the
2400 appropriate Makefile variables. (From a patch by Carsten Larsen.)
2403 Release 2016h - 2016-10-19 23:17:57 -0700
2405 Changes to future timestamps
2407 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2408 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
2409 future fall transitions will be on the last Saturday of October
2410 at 01:00, which is consistent with predicted spring transitions
2411 on the last Saturday of March. (Thanks to Tim Parenti.)
2413 Changes to past timestamps
2415 In Turkey, transitions in 1986-1990 were at 01:00 standard time
2416 not at 02:00, and the spring 1994 transition was on March 20, not
2417 March 27. (Thanks to Kıvanç Yazan.)
2419 Changes to past and future time zone abbreviations
2421 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
2422 instead of alphabetic ones like "IST" and "LKT". Various
2423 English-language sources use "IST", "LKT" and "SLST", with no
2424 working consensus. (Usage of "SLST" mentioned by Sadika
2429 zic no longer mishandles relativizing file names when creating
2430 symbolic links like /etc/localtime, when these symbolic links
2431 are outside the usual directory hierarchy. This fixes a bug
2432 introduced in 2016g. (Problem reported by Andreas Stieger.)
2434 Changes to build procedure
2436 New rules 'traditional_tarballs' and 'traditional_signatures' for
2437 building just the traditional-format distribution. (Requested by
2440 The file 'version' is now put into the tzdata tarball too.
2441 (Requested by Howard Hinnant.)
2443 Changes to documentation and commentary
2445 The 'Theory' file now has a section on interface stability.
2446 (Requested by Paul Koning.) It also mentions features like
2447 tm_zone and localtime_rz that have long been supported by the
2450 tz-link.htm has improved coverage of time zone boundaries suitable
2451 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
2454 The US commentary now mentions Allen and the "day of two noons".
2456 The Fiji commentary mentions the government's 2016-10-03 press
2457 release. (Thanks to Raymond Kumar.)
2460 Release 2016g - 2016-09-13 08:56:38 -0700
2462 Changes to future timestamps
2464 Turkey switched from EET/EEST (+02/+03) to permanent +03,
2465 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
2466 than an invented abbreviation for the new time.
2468 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
2469 (Thanks to Tim Parenti.)
2471 Changes to past timestamps
2473 For America/Los_Angeles, spring-forward transition times have been
2474 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2477 For zones using Soviet time on 1919-07-01, transitions to UT-based
2478 time were at 00:00 UT, not at 02:00 local time. The affected
2479 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2480 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2482 Changes to past and future time zone abbreviations
2484 The Factory zone now uses the time zone abbreviation -00 instead
2485 of a long English-language string, as -00 is now the normal way to
2486 represent an undefined time zone.
2488 Several zones in Antarctica and the former Soviet Union, along
2489 with zones intended for ships at sea that cannot use POSIX TZ
2490 strings, now use numeric time zone abbreviations instead of
2491 invented or obsolete alphanumeric abbreviations. The affected
2492 zones are Antarctica/Casey, Antarctica/Davis,
2493 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2494 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2495 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2496 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2497 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2498 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2499 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2500 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2501 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2502 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2503 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2504 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2505 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2506 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2507 was replaced by +05, whereas MSK and MSD were kept as they are not
2508 our invention and are widely used.
2510 Changes to zone names
2512 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2513 (Thanks to David Massoud.)
2517 zic no longer generates binary files containing POSIX TZ-like
2518 strings that disagree with the local time type after the last
2519 explicit transition in the data. This fixes a bug with
2520 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2521 on the reference platform. (Thanks to Alexander Belopolsky for
2522 reporting the bug and suggesting a way forward.)
2524 If the installed localtime and/or posixrules files are symbolic
2525 links, zic now keeps them symbolic links when updating them, for
2526 compatibility with platforms like OpenSUSE where other programs
2527 configure these files as symlinks.
2529 zic now avoids hard linking to symbolic links, avoids some
2530 unnecessary mkdir and stat system calls, and uses shorter file
2533 zdump has a new -i option to generate transitions in a
2534 smaller but still human-readable format. This option is
2535 experimental, and the output format may change in future versions.
2536 (Thanks to Jon Skeet for suggesting that an option was needed,
2537 and thanks to Tim Parenti and Chris Rovick for further comments.)
2539 Changes to build procedure
2541 An experimental distribution format is available, in addition
2542 to the traditional format which will continue to be distributed.
2543 The new format is a tarball tzdb-VERSION.tar.lz with signature
2544 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2545 tzdb-VERSION containing the code and data of the traditional
2546 two-tarball format, along with extra data that may be useful.
2547 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2548 for comments about the experimental format.)
2550 The release version number is now more accurate in the usual case
2551 where releases are built from a Git repository. For example, if
2552 23 commits and some working-file changes have been made since
2553 release 2016g, the version number is now something like
2554 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2555 Tagged releases use the same version number format as before,
2556 e.g., '2016g'. To support the more accurate version number, its
2557 specification has moved from a line in the Makefile to a new
2558 source file 'version'.
2560 The experimental distribution contains a file to2050.tzs that
2561 contains what should be the output of 'zdump -i -c 2050' on
2562 primary zones. If this file is available, 'make check' now checks
2563 that zdump generates this output.
2565 'make check_web' now works on Fedora-like distributions.
2567 Changes to documentation and commentary
2569 tzfile.5 now documents the new restriction on POSIX TZ-like
2570 strings that is now implemented by zic.
2572 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2573 (Thanks to Alexander Belopolsky.)
2575 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2576 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2577 description of Java 8 has been brought up to date (thanks to
2578 Stephen Colebourne). Its description of local time on Mars has
2579 been updated to match current practice, and URLs have been updated
2580 and some obsolete ones removed.
2583 Release 2016f - 2016-07-05 16:26:51 +0200
2585 Changes affecting future timestamps
2587 The Egyptian government changed its mind on short notice, and
2588 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2589 (Thanks to Mina Samuel.)
2591 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2592 (Thanks to Stepan Golosunov.)
2594 Changes to past and future timestamps
2596 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2597 abbreviations instead of invented ones.
2599 Changes affecting past timestamps
2601 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2602 (Thanks to Stepan Golosunov.)
2605 Release 2016e - 2016-06-14 08:46:16 -0700
2607 Changes affecting future timestamps
2609 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2610 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2611 For future years, guess April's last Thursday to October's last
2612 Thursday except for Ramadan.
2614 Changes affecting past timestamps
2616 Locations while uninhabited now use '-00', not 'zzz', as a
2617 placeholder time zone abbreviation. This is inspired by Internet
2618 RFC 3339 and is more consistent with numeric time zone
2619 abbreviations already used elsewhere. The change affects several
2620 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2621 1920 and Antarctica/Troll before 2005.
2623 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2624 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2628 zic now outputs a dummy transition at time 2**31 - 1 in zones
2629 whose POSIX-style TZ strings contain a '<'. This mostly works
2630 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2631 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2633 Changes affecting documentation and commentary
2635 tz-link.htm says why governments should give plenty of notice for
2636 time zone or DST changes, and refers to Matt Johnson's blog post.
2638 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2641 Release 2016d - 2016-04-17 22:50:29 -0700
2643 Changes affecting future timestamps
2645 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2646 (Thanks to Alexander Krivenyshev for the heads-up.)
2648 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2649 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2651 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2652 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2653 at 02:00. (Thanks to Stepan Golosunov.)
2655 Changes affecting past timestamps
2657 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2658 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2659 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2660 the same change. (Thanks to Stepan Golosunov.)
2662 Russia and nearby locations had daylight-saving transitions on
2663 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2664 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2667 Many corrections to historical time in Kazakhstan from 1991
2668 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2669 invented time zone abbreviations with numeric abbreviations.
2671 Changes to commentary
2673 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2676 Release 2016c - 2016-03-23 00:51:27 -0700
2678 Changes affecting future timestamps
2680 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2682 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2683 Correa for the heads-up, and to Tim Parenti for corrections.)
2684 Guess that future transitions are August's and May's second
2685 Saturdays at 24:00 mainland time. Also, call the period from
2686 2014-09-07 through 2016-05-14 daylight saving time instead of
2687 standard time, as that seems more appropriate now.
2689 Changes affecting past timestamps
2691 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2692 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2693 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2694 (Thanks to Stepan Golosunov.)
2696 Changes to commentary
2698 Several updates and URLs for historical and proposed Russian changes.
2699 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2702 Release 2016b - 2016-03-12 17:30:14 -0800
2706 Starting with release 2016b, some data entries cause zic implementations
2707 derived from tz releases 2005j through 2015e to issue warnings like
2708 "time zone abbreviation differs from POSIX standard (+03)".
2709 These warnings should not otherwise affect zic's output and can safely be
2710 ignored on today's platforms, as the warnings refer to a restriction in
2711 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2712 warnings is to upgrade to zic derived from tz releases 2015f and later.
2714 Changes affecting future timestamps
2716 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2717 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2718 2016-03-27 at 02:00 local time. They need distinct zones since their
2719 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2720 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2721 and local time. The Astrakhan change is already official; the others have
2722 passed the first reading in the State Duma and are extremely likely.
2723 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2724 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2725 and Stepan Golosunov for followup.)
2727 As a trial of a new system that needs less information to be made up,
2728 the new zones use numeric time zone abbreviations like "+04"
2729 instead of invented abbreviations like "ASTT".
2731 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2734 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2735 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2736 Saturday at 01:00, not March's last Friday at 24:00.
2738 Changes affecting past timestamps
2740 Europe/Chisinau observed DST during 1990, and switched from +04 to
2741 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2742 (Thanks to Stepan Golosunov.)
2744 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2745 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2749 tzselect's diagnostics and checking, and checktab.awk's checking,
2750 have been improved. (Thanks to J William Piggott.)
2752 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2754 tzselect now tests Julian-date TZ settings more accurately.
2755 (Thanks to J William Piggott.)
2757 Changes to commentary
2759 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2761 tzselect again limits its menu comments so that menus fit on a
2762 24×80 alphanumeric display.
2764 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2766 In the Theory file, the description of possible time zone abbreviations in
2767 tzdata has been cleaned up, as the old description was unclear and
2768 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2771 Release 2016a - 2016-01-26 23:28:02 -0800
2773 Changes affecting future timestamps
2775 America/Cayman will not observe daylight saving this year after all.
2776 Revert our guess that it would. (Thanks to Matt Johnson.)
2778 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2779 (Thanks to Alexander Krivenyshev.)
2781 Asia/Tehran now has DST predictions for the year 2038 and later,
2782 to be March 21 00:00 to September 21 00:00. This is likely better
2783 than predicting no DST, albeit off by a day every now and then.
2785 Changes affecting past and future timestamps
2787 America/Metlakatla switched from PST all year to AKST/AKDT on
2788 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2790 America/Santa_Isabel has been removed, and replaced with a
2791 backward compatibility link to America/Tijuana. Its contents were
2792 apparently based on a misreading of Mexican legislation.
2794 Changes affecting past timestamps
2796 Asia/Karachi's two transition times in 2002 were off by a minute.
2797 (Thanks to Matt Johnson.)
2799 Changes affecting build procedure
2801 An installer can now combine leap seconds with use of the backzone file,
2802 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2803 The old 'make posix_packrat' rule is now marked as obsolescent.
2804 (Thanks to Ian Abbott for an initial implementation.)
2806 Changes affecting documentation and commentary
2808 A new file LICENSE makes it easier to see that the code and data
2809 are mostly public-domain. (Thanks to James Knight.) The three
2810 non-public-domain files now use the current (3-clause) BSD license
2811 instead of older versions of that license.
2813 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2814 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2815 on editing tz source files (with a mention of Sublime zoneinfo,
2816 thanks to Gilmore Davidson).
2818 The Theory and asia files now mention the 2015 book "The Global
2819 Transformation of Time, 1870-1950", and cite a couple of reviews.
2821 The America/Chicago entry now documents the informal use of US
2822 central time in Fort Pierre, South Dakota. (Thanks to Rick
2823 McDermid, Matt Johnson, and Steve Jones.)
2826 Release 2015g - 2015-10-01 00:39:51 -0700
2828 Changes affecting future timestamps
2830 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2833 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2834 (Thanks to Alexander Krivenyshev.)
2836 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2837 (Thanks to Ken Rylander.)
2839 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2840 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2841 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2843 Changes affecting past timestamps
2845 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2847 Changes affecting code
2849 localtime no longer mishandles America/Anchorage after 2037.
2850 (Thanks to Bradley White for reporting the bug.)
2852 On hosts with signed 32-bit time_t, localtime no longer mishandles
2853 Pacific/Fiji after 2038-01-16 14:00 UTC.
2855 The localtime module allows the variables 'timezone', 'daylight',
2856 and 'altzone' to be in common storage shared with other modules,
2857 and declares them in case the system <time.h> does not.
2858 (Problems reported by Kees Dekker.)
2860 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2861 This simplifies the code and is consistent with zdump.c.
2862 (Problem reported by Christos Zoulas.)
2864 Changes affecting documentation
2866 The tzfile man page now documents that transition times denote the
2867 starts (not the ends) of the corresponding time periods.
2868 (Ambiguity reported by Bill Seymour.)
2871 Release 2015f - 2015-08-10 18:06:56 -0700
2873 Changes affecting future timestamps
2875 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2876 The abbreviation remains "KST". (Thanks to Robert Elz.)
2878 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2881 Changes affecting past and future timestamps
2883 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2884 (Thanks to Roman Tudos.)
2886 Changes affecting data format and code
2888 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2889 field of a Rule line should now be '-'; the old values 'even',
2890 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2891 Although the implementation has not changed, these features do not
2892 work in the default installation, they are not used in the data,
2893 and they are now considered obsolescent.
2895 zic now checks that two rules don't take effect at the same time.
2896 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2897 simultaneity are now documented.
2899 The two characters '%z' in a zone format now stand for the UT
2900 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2901 five hours and thirty minutes ahead. This better supports time
2902 zone abbreviations conforming to POSIX.1-2001 and later.
2904 Changes affecting installed data files
2906 Comments for America/Halifax and America/Glace_Bay have been improved.
2907 (Thanks to Brian Inglis.)
2909 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2910 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2911 installed data files for Europe/Simferopol and Europe/Tallinn.
2912 It does not affect timestamps. (Thanks to Howard Hinnant.)
2914 Changes affecting code
2916 zdump and zic no longer warn about valid time zone abbreviations
2919 Some Visual Studio 2013 warnings have been suppressed.
2920 (Thanks to Kees Dekker.)
2922 'date' no longer sets the time of day and its -a, -d, -n and -t
2923 options have been removed. Long obsolescent, the implementation
2924 of these features had porting problems. Builders no longer need
2925 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2926 (Thanks to Kees Dekker for pointing out the problem.)
2928 Changes affecting documentation
2930 The Theory file mentions naming issues earlier, as these seem to be
2931 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2933 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2935 Mention that Herbert Samuel introduced the term "Summer Time".
2938 Release 2015e - 2015-06-13 10:56:02 -0700
2940 Changes affecting future timestamps
2942 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2943 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2945 Assume Cayman Islands will observe DST starting next year, using US rules.
2946 Although it isn't guaranteed, it is the most likely.
2948 Changes affecting data format
2950 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2951 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2953 Changes affecting code
2955 When displaying data, tzselect converts it to the current locale's
2956 encoding if the iconv command works. (Problem reported by random832.)
2958 tzselect no longer mishandles Dominica, fixing a bug introduced
2959 in Release 2014f. (Problem reported by Owen Leibman.)
2961 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2962 This fixes a bug introduced in Release 2014f.
2963 (Problem reported by Leonardo Chiquitto.)
2966 Release 2015d - 2015-04-24 08:09:46 -0700
2968 Changes affecting future timestamps
2970 Egypt will not observe DST in 2015 and will consider canceling it
2971 permanently. For now, assume no DST indefinitely.
2972 (Thanks to Ahmed Nazmy and Tim Parenti.)
2974 Changes affecting past timestamps
2976 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2977 1966-07-01. Also, Yukon's time zone history is documented better.
2978 (Thanks to Brian Inglis and Dennis Ferguson.)
2980 Change affecting past and future time zone abbreviations
2982 The abbreviations for Hawaii-Aleutian standard and daylight times
2983 have been changed from HAST/HADT to HST/HDT, as per US Government
2984 Printing Office style. This affects only America/Adak since 1983,
2985 as America/Honolulu was already using the new style.
2987 Changes affecting code
2989 zic has some minor performance improvements.
2992 Release 2015c - 2015-04-11 08:55:55 -0700
2994 Changes affecting future timestamps
2996 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2997 not 00:00 on April's last Friday. 2015's transition will therefore be on
2998 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2999 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
3001 Changes affecting past timestamps
3003 The following changes affect some pre-1991 Chile-related timestamps
3004 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
3006 The 1910 transition was January 10, not January 1.
3008 The 1918 transition was September 10, not September 1.
3010 The UT -04 time observed from 1932 to 1942 is now considered to
3011 be standard time, not year-round DST.
3013 Santiago observed DST (UT -03) from 1946-07-15 through
3014 1946-08-31, then reverted to standard time, then switched to -05
3017 Assume transitions before 1968 were at 00:00, since we have no data
3020 The spring 1988 transition was 1988-10-09, not 1988-10-02.
3021 The fall 1990 transition was 1990-03-11, not 1990-03-18.
3023 Assume no UT offset change for Pacific/Easter on 1890-01-01,
3024 and omit all transitions on Pacific/Easter from 1942 through 1946
3025 since we have no data suggesting that they existed.
3027 One more zone has been turned into a link, as it differed
3028 from an existing zone only for older timestamps. As usual,
3029 this change affects UT offsets in pre-1970 timestamps only.
3030 The zone's old contents have been moved to the 'backzone' file.
3031 The affected zone is America/Montreal.
3033 Changes affecting commentary
3035 Mention the TZUpdater tool.
3037 Mention "The Time Now". (Thanks to Brandon Ramsey.)
3040 Release 2015b - 2015-03-19 23:28:11 -0700
3042 Changes affecting future timestamps
3044 Mongolia will start observing DST again this year, from the last
3045 Saturday in March at 02:00 to the last Saturday in September at 00:00.
3046 (Thanks to Ganbold Tsagaankhuu.)
3048 Palestine will start DST on March 28, not March 27. Also,
3049 correct the fall 2014 transition from September 26 to October 24.
3050 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
3052 Changes affecting past timestamps
3054 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
3055 regression. (Thanks to Stuart Bishop for reporting the problem.)
3057 Some more zones have been turned into links, when they differed
3058 from existing zones only for older timestamps. As usual,
3059 these changes affect UT offsets in pre-1970 timestamps only.
3060 Their old contents have been moved to the 'backzone' file.
3061 The affected zones are: America/Antigua, America/Cayman,
3062 Pacific/Midway, and Pacific/Saipan.
3064 Changes affecting time zone abbreviations
3066 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
3069 Changes affecting code
3071 Fix integer overflow bug in reference 'mktime' implementation.
3072 (Problem reported by Jörg Richter.)
3074 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
3075 to be used in the same executable as standard-library time_t functions.
3076 (Problems reported by Bradley White.)
3078 Changes affecting commentary
3080 Cite the recent Mexican decree changing Quintana Roo's time zone.
3081 (Thanks to Carlos Raúl Perasso.)
3083 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
3085 Update info about Mars time.
3088 Release 2015a - 2015-01-29 22:35:20 -0800
3090 Changes affecting future timestamps
3092 The Mexican state of Quintana Roo, represented by America/Cancun,
3093 will shift from Central Time with DST to Eastern Time without DST
3094 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
3096 Chile will not change clocks in April or thereafter; its new standard time
3097 will be its old daylight saving time. This affects America/Santiago,
3098 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
3100 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
3101 (Thanks to Tim Parenti.)
3103 Changes affecting past timestamps
3105 Iceland observed DST in 1919 and 1921, and its 1939 fallback
3106 transition was Oct. 29, not Nov. 29. Remove incorrect data from
3107 Shanks about time in Iceland between 1837 and 1908.
3109 Some more zones have been turned into links, when they differed
3110 from existing zones only for older timestamps. As usual,
3111 these changes affect UT offsets in pre-1970 timestamps only.
3112 Their old contents have been moved to the 'backzone' file.
3113 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
3116 Changes affecting code
3118 tzalloc now scrubs time zone abbreviations compatibly with the way
3119 that tzset always has, by replacing invalid bytes with '_' and by
3120 shortening too-long abbreviations.
3122 tzselect ports to POSIX awk implementations, no longer mishandles
3123 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
3124 settings to the user. (Thanks to Stefan Kuhn.)
3126 Changes affecting build procedure
3128 'make check' now checks for links to links in the data.
3129 One such link (for Africa/Asmera) has been fixed.
3130 (Thanks to Stephen Colebourne for pointing out the problem.)
3132 Changes affecting commentary
3134 The leapseconds file commentary now mentions the expiration date.
3135 (Problem reported by Martin Burnicki.)
3137 Update Mexican Library of Congress URL.
3140 Release 2014j - 2014-11-10 17:37:11 -0800
3142 Changes affecting current and future timestamps
3144 Turks & Caicos' switch from US eastern time to UT -04 year-round
3145 did not occur on 2014-11-02 at 02:00. It's currently scheduled
3146 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
3148 Changes affecting past timestamps
3150 Many pre-1989 timestamps have been corrected for Asia/Seoul and
3151 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
3152 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
3153 longer guess that Pyongyang mimicked Seoul time after World War II,
3154 as this is politically implausible.
3156 Some more zones have been turned into links, when they differed
3157 from existing zones only for older timestamps. As usual,
3158 these changes affect UT offsets in pre-1970 timestamps only.
3159 Their old contents have been moved to the 'backzone' file.
3160 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
3161 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
3162 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
3165 Changes affecting commentary
3167 The commentary is less enthusiastic about Shanks as a source,
3168 and is more careful to distinguish UT from UTC.
3171 Release 2014i - 2014-10-21 22:04:57 -0700
3173 Changes affecting future timestamps
3175 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
3176 (Thanks to Ken Rylander for the heads-up.) Guess that future
3177 years will use a similar pattern.
3179 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
3180 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
3181 (Thanks to Kiley Walbom for the heads-up.)
3183 Changes affecting time zone abbreviations
3185 Since Belarus is not changing its clocks even though Moscow is,
3186 the time zone abbreviation in Europe/Minsk is changing from FET
3187 to its more traditional value MSK on 2014-10-26 at 01:00.
3188 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
3190 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
3191 Indochina, to distinguish it better from ICT (+07).
3193 Changes affecting past timestamps
3195 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
3196 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
3197 authoritative book). Asia/Ho_Chi_Minh has been added to
3198 zone1970.tab, to give tzselect users in Vietnam two choices,
3199 since north and south Vietnam disagreed after our 1970 cutoff.
3201 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
3202 they differed from existing zones only for older timestamps. As
3203 usual, these changes affect pre-1970 timestamps only. Their old
3204 contents have been moved to the 'backzone' file.
3206 Changes affecting code
3208 The time-related library functions now set errno on failure, and
3209 some crashes in the new tzalloc-related library functions have
3210 been fixed. (Thanks to Christos Zoulas for reporting most of
3211 these problems and for suggesting fixes.)
3213 If USG_COMPAT is defined and the requested timestamp is standard time,
3214 the tz library's localtime and mktime functions now set the extern
3215 variable timezone to a value appropriate for that timestamp; and
3216 similarly for ALTZONE, daylight saving time, and the altzone variable.
3217 This change is a companion to the tzname change in 2014h, and is
3218 designed to make timezone and altzone more compatible with tzname.
3220 The tz library's functions now set errno to EOVERFLOW if they fail
3221 because the result cannot be represented. ctime and ctime_r now
3222 return NULL and set errno when a timestamp is out of range, rather
3223 than having undefined behavior.
3225 Some bugs associated with the new 2014g functions have been fixed.
3226 This includes a bug that largely incapacitated the new functions
3227 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
3228 It also includes some uses of uninitialized variables after tzalloc.
3229 The new code uses the standard type 'ssize_t', which the Makefile
3230 now gives porting advice about.
3232 Changes affecting commentary
3234 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
3237 Release 2014h - 2014-09-25 18:59:03 -0700
3239 Changes affecting past timestamps
3241 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
3243 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
3244 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
3246 Some more zones have been turned into links, when they differed
3247 from existing zones only for older timestamps. As usual,
3248 these changes affect UT offsets in pre-1970 timestamps only.
3249 Their old contents have been moved to the 'backzone' file.
3250 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
3251 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
3252 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
3254 Changes affecting code
3256 zdump -V and -v now output gmtoff= values on all platforms,
3257 not merely on platforms defining TM_GMTOFF.
3259 The tz library's localtime and mktime functions now set tzname to a value
3260 appropriate for the requested timestamp, and zdump now uses this
3261 on platforms not defining TM_ZONE, fixing a 2014g regression.
3262 (Thanks to Tim Parenti for reporting the problem.)
3264 The tz library no longer sets tzname if localtime or mktime fails.
3266 zdump -c no longer mishandles transitions near year boundaries.
3267 (Thanks to Tim Parenti for reporting the problem.)
3269 An access to uninitialized data has been fixed.
3270 (Thanks to Jörg Richter for reporting the problem.)
3272 When THREAD_SAFE is defined, the code ports to the C11 memory model.
3273 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
3274 and two threads race to initialize data used by gmtime-like functions.
3275 (Thanks to Andy Heninger for reporting the problems.)
3277 Changes affecting build procedure
3279 'make check' now checks better for properly sorted data.
3281 Changes affecting documentation and commentary
3283 zdump's gmtoff=N output is now documented, and its isdst=D output
3284 is now documented to possibly output D values other than 0 or 1.
3286 zdump -c's treatment of years is now documented to use the
3287 Gregorian calendar and Universal Time without leap seconds,
3288 and its behavior at cutoff boundaries is now documented better.
3289 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
3291 Programs are now documented to use the proleptic Gregorian calendar.
3292 (Thanks to Alan Barrett for the suggestion.)
3294 Fractional-second GMT offsets have been documented for civil time
3295 in 19th-century Chennai, Jakarta, and New York.
3298 Release 2014g - 2014-08-28 12:31:23 -0700
3300 Changes affecting future timestamps
3302 Turks & Caicos is switching from US eastern time to UT -04
3303 year-round, modeled as a switch on 2014-11-02 at 02:00.
3304 [As noted in 2014j, this switch was later delayed.]
3306 Changes affecting past timestamps
3308 Time in Russia or the USSR before 1926 or so has been corrected by
3309 a few seconds in the following zones: Asia/Irkutsk,
3310 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
3311 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
3312 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
3313 Vladimir Karpinsky.)
3315 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
3316 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
3317 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
3318 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
3319 (Thanks to Stephen Colebourne for pointing to the decree.)
3321 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
3323 A new file 'backzone' contains data which may appeal to
3324 connoisseurs of old timestamps, although it is out of scope for
3325 the tz database, is often poorly sourced, and contains some data
3326 that is known to be incorrect. The new file is not recommended
3327 for ordinary use and its entries are not installed by default.
3328 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
3329 Isle of Man entries.)
3331 Some more zones have been turned into links, when they differed
3332 from existing zones only for older timestamps. As usual,
3333 these changes affect UT offsets in pre-1970 timestamps only.
3334 Their old contents have been moved to the 'backzone' file.
3335 The affected zones are: Africa/Bangui, Africa/Brazzaville,
3336 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
3337 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
3339 Changes affecting code
3341 Unless NETBSD_INSPIRED is defined to 0, the tz library now
3342 supplies functions for creating and using objects that represent
3343 timezones. The new functions are tzalloc, tzfree, localtime_rz,
3344 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
3345 time2posix_z. They are intended for performance: for example,
3346 localtime_rz (unlike localtime_r) is trivially thread-safe without
3347 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
3348 functions, and to Alan Barrett and Jonathan Lennox for helping to
3351 zdump now builds with the tz library unless USE_LTZ is defined to 0,
3352 This lets zdump use tz features even if the system library lacks them.
3353 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
3354 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
3356 zdump now uses localtime_rz if available, as it's significantly faster,
3357 and it can help zdump better diagnose invalid timezone names.
3358 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
3359 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
3360 not available, zdump now uses localtime_r and tzset if available,
3361 as this is a bit cleaner and faster than plain localtime. Compile
3362 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
3363 lacks these two functions.
3365 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
3366 Although not needed for tz's own applications, which are single-threaded,
3367 this supports POSIX better if the tz library is used in multithreaded apps.
3369 Some crashes have been fixed when zdump or the tz library is given
3370 invalid or outlandish input.
3372 The tz library no longer mishandles leap seconds on platforms with
3373 unsigned time_t in timezones that lack ordinary transitions after 1970.
3375 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
3376 already defined, to make it easier to configure on common platforms.
3377 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
3379 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
3380 assumes that reading uninitialized memory yields garbage values
3381 but does not cause other problems such as traps.
3383 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
3384 more likely to guess right for ambiguous timestamps near
3385 transitions where tm_isdst does not change.
3387 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
3388 strftime_l for compatibility with recent versions of POSIX.
3389 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
3390 to 1 on recent POSIX versions, and to 0 otherwise.
3392 tzselect -c now uses a hybrid distance measure that works better
3393 in Africa. (Thanks to Alan Barrett for noting the problem.)
3395 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
3396 or when time_tz is defined.
3398 When HAVE_UTMPX_H is set the 'date' command now builds on systems
3399 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
3400 the date it updates the wtmpx file if _PATH_WTMPX is defined.
3401 This affects GNU/Linux and similar systems.
3403 For easier maintenance later, some C code has been simplified,
3404 some lint has been removed, and the code has been tweaked so that
3405 plain 'make' is more likely to work.
3407 The C type 'bool' is now used for boolean values, instead of 'int'.
3409 The long-obsolete LOCALE_HOME code has been removed.
3411 The long-obsolete 'gtime' function has been removed.
3413 Changes affecting build procedure
3415 'zdump' no longer links in ialloc.o, as it's not needed.
3417 'make check_time_t_alternatives' no longer assumes GNU diff.
3419 Changes affecting distribution tarballs
3421 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
3422 the tzdata tarball instead of the tzcode tarball, since they help
3423 maintain the data. The NEWS and Theory files are now also
3424 distributed in the tzdata tarball, as they're relevant for data.
3425 (Thanks to Alan Barrett for pointing this out.) Also, the
3426 leapseconds.awk file is no longer distributed in the tzcode
3427 tarball, since it belongs in the tzdata tarball (where 2014f
3428 inadvertently also distributed it).
3430 Changes affecting documentation and commentary
3432 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
3433 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
3436 The man pages have been updated to use function prototypes,
3437 to document thread-safe variants like localtime_r, and to document
3438 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
3441 The fields in Link lines have been renamed to be more descriptive
3442 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
3443 and LINK-TO has become LINK-NAME.
3445 tz-link.htm mentions the IETF's tzdist working group; Windows
3446 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
3448 Some broken URLs have been fixed in the commentary. (Thanks to
3451 Commentary about Philippines DST has been updated, and commentary
3452 on pre-1970 time in India has been added.
3455 Release 2014f - 2014-08-05 17:42:36 -0700
3457 Changes affecting future timestamps
3459 Russia will subtract an hour from most of its time zones on 2014-10-26
3460 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
3461 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
3462 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
3463 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
3464 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
3465 (Europe/Samara) are not changing their clocks. The changed zones are
3466 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
3467 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
3468 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
3469 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
3470 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
3471 but not its UTC offset. Two zones are added: Asia/Chita (split
3472 from Asia/Yakutsk, and also with two hours subtracted) and
3473 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
3474 subtracted). (Thanks to Tim Parenti for much of the above.)
3476 Changes affecting time zone abbreviations
3478 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3479 and similarly for the other Australian zones. That is, for eastern
3480 standard and daylight saving time the abbreviations are AEST and AEDT
3481 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3482 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3483 This change does not affect UT offsets, only time zone abbreviations.
3484 (Thanks to Rich Tibbett and many others.)
3486 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3487 effective 2014-10-26 at 02:00 local time.
3489 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3490 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3492 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3493 Similarly, prefer EET/EEST for eastern European time in Russia.
3495 Change time zone abbreviations in (western) Samoa to use "ST" and
3496 "DT" suffixes, as this is more likely to match common practice.
3497 Prefix "W" to (western) Samoa time when its standard-time offset
3498 disagrees with that of American Samoa.
3500 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3502 Time zone abbreviations have been updated for Japan's two time
3503 zones used 1896-1937. JWST now stands for Western Standard
3504 Time, and JCST for Central Standard Time (formerly this was CJT).
3505 These abbreviations are now used for time in Korea, Taiwan,
3506 and Sakhalin while controlled by Japan.
3508 Changes affecting past timestamps
3510 China's five zones have been simplified to two, since the post-1970
3511 differences in the other three seem to have been imaginary. The
3512 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3513 removed; backwards-compatibility links still work, albeit with
3514 different behaviors for timestamps before May 1980. Asia/Urumqi's
3515 1980 transition to UT +08 has been removed, so that it is now at
3516 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3517 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3519 Some zones have been turned into links, when they differed from existing
3520 zones only for older UT offsets where data entries were likely invented.
3521 These changes affect UT offsets in pre-1970 timestamps only. This is
3522 similar to the change in release 2013e, except this time for western
3523 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3524 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3525 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3526 Atlantic/St_Helena. This also affects the backwards-compatibility
3527 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3528 Tim Parenti, and David Patte for reporting problems in earlier
3529 versions of this change.)
3531 Asia/Shanghai's pre-standard-time UT offset has been changed from
3532 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3533 transition to standard time has been changed from 1928 to 1901.
3535 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3536 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3537 In 1946 it observed DST from 05-15 through 09-30; in 1947
3538 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3539 (Thanks to Yu-Cheng Chuang.)
3541 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3543 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3544 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3546 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3547 period from 1911 to 1950.
3549 Pacific/Chatham has been changed to New Zealand standard time plus
3550 45 minutes for the period before 1957, reflecting a 1956 remark in
3551 the New Zealand parliament.
3553 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3554 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3555 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3556 not 04-06 at 02:00; and there was no DST in 1920.
3558 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3560 Time in Russia before 1927 or so has been corrected by a few seconds in
3561 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3562 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3563 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3564 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3566 Changes affecting data format
3568 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3569 The new file's extended format allows multiple country codes per zone.
3570 The older file is still installed but is deprecated; its format is
3571 not changing and it will still be distributed for a while, but new
3572 applications should use the new file.
3574 The new file format simplifies maintenance of obscure locations.
3575 To test this, it adds coverage for the Crozet Islands and the
3576 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3578 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3579 It is still ASCII now, but commentary about the switch has been added.
3580 The new file 'zone1970.tab' already uses UTF-8.
3582 Changes affecting code
3584 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3585 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3587 'zic' no longer mishandles input when ignoring case in locales that
3588 are not compatible with English, e.g., unibyte Turkish locales when
3589 compiled with HAVE_GETTEXT.
3591 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3592 they no longer use ASCII '-' as if it were a dash.
3594 'zic' now rejects output file names that contain '.' or '..' components.
3595 (Thanks to Tim Parenti for reporting the problem.)
3597 'zic -v' now warns about output file names that do not follow
3598 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3599 David Olson for starting the ball rolling on this.)
3601 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3603 Changes affecting build procedure
3605 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3606 (Thanks to John Cochran.)
3608 Changes affecting documentation and commentary
3610 The 'Theory' file documents legacy names, the longstanding
3611 exceptions to the POSIX-inspired file name rules.
3613 The 'zic' documentation clarifies the role of time types when
3614 interpreting dates. (Thanks to Arthur David Olson.)
3616 Documentation and commentary now prefer UTF-8 to US-ASCII,
3617 allowing the use of proper accents in foreign words and names.
3618 Code and data have not changed because of this. (Thanks to
3619 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3622 Non-HTML documentation and commentary now use plain-text URLs instead of
3623 HTML insertions, and are more consistent about bracketing URLs when they
3624 are not already surrounded by white space. (Thanks to suggestions by
3627 There is new commentary about Xujiahui Observatory, the five time-zone
3628 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3629 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3630 warlord Jin Shuren in the data.
3632 Commentary about the coverage of each Russian zone has been standardized.
3633 (Thanks to Tim Parenti.)
3635 There is new commentary about contemporary timekeeping in Ethiopia.
3637 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3639 There is new commentary about time in Poland in 1919.
3641 Proper credit has been given to DST inventor George Vernon Hudson.
3643 Commentary about time in Metlakatla, AK and Resolute, NU has been
3644 improved, with a new source for the former.
3646 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3649 Commentary about permanent Antarctic bases has been updated.
3651 Several typos have been corrected. (Thanks to Tim Parenti for
3652 contributing some of these fixes.)
3654 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3655 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3656 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3657 (Thanks to a heads-up from Dirkjan Ochtman.)
3659 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3660 have been removed. These obsolescent US Naval Observatory entries were no
3661 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3664 Release 2014e - 2014-06-12 21:53:52 -0700
3666 Changes affecting near-future timestamps
3668 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3669 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3670 switch to standard time at 24:00 the last Thursday before Ramadan, and
3671 back to DST at 00:00 the first Friday after Ramadan.
3673 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3674 to Milamber Space Network.) Guess that from 2015 on Morocco will
3675 temporarily switch to standard time at 03:00 the last Saturday before
3676 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3678 Changes affecting past timestamps
3680 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3681 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3682 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3683 in 1991. (Thanks to Hank W. for reporting the problems.)
3685 Changes affecting commentary
3687 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3688 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3689 removes stale pointers to World Time Explorer and WORLDTIME.
3692 Release 2014d - 2014-05-27 21:34:40 -0700
3694 Changes affecting code
3696 zic no longer generates files containing timestamps before the Big Bang.
3697 This works around GNOME glib bug 878
3698 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3699 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3700 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3702 Changes affecting documentation
3704 tz-link.htm now mentions GNOME.
3707 Release 2014c - 2014-05-13 07:44:13 -0700
3709 Changes affecting near-future timestamps
3711 Egypt observes DST starting 2014-05-15 at 24:00.
3712 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3713 Details have not been announced, except that DST will not be observed
3714 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3715 Morocco, and that Egypt's future spring and fall transitions will be the
3716 same as 2010 when it last observed DST, namely April's last Friday at
3717 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3718 that Ramadan transitions will be at 00:00 standard time.
3720 Changes affecting code
3722 zic now generates transitions for minimum time values, eliminating guesswork
3723 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3725 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3727 Changes affecting commentary and documentation
3729 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3732 Release 2014b - 2014-03-24 21:28:50 -0700
3734 Changes affecting near-future timestamps
3736 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3737 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3739 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3740 Bengt-Inge Larsson.) This is currently an approximation; a better version
3741 will require the zic and localtime fixes mentioned below, and the plan is
3742 to wait for a while until at least the zic fixes propagate.
3744 Changes affecting code
3746 'zic' and 'localtime' no longer reject locations needing four transitions
3747 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3748 Also, 'zic' avoids some unlikely failures due to integer overflow.
3750 Changes affecting build procedure
3752 'make check' now detects Rule lines defined but never used.
3753 The NZAQ rules, an instance of this problem, have been removed.
3755 Changes affecting commentary and documentation
3757 Fix Tuesday/Thursday typo in description of time in Israel.
3758 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3760 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3761 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3762 library supports them.
3764 Add comments about Johnston Island time in the 1960s.
3765 (Thanks to Lyle McElhaney.)
3767 Morocco's 2014 DST start will be as predicted.
3768 (Thanks to Sebastien Willemijns.)
3771 Release 2014a - 2014-03-07 23:30:29 -0800
3773 Changes affecting near-future timestamps
3775 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3776 the heads-up, and to Tim Parenti for simplifying the update.)
3778 Changes affecting past timestamps
3780 Fiji ended DST on 2014-01-19 at 02:00, not the previously scheduled 03:00.
3781 (Thanks to Steffen Thorsen.)
3783 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3784 (not 1992-01-01), and observed DST during the entire next winter.
3785 (Thanks to Vladimir in Moscow via Alois Treindl.)
3787 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3788 (Thanks to Avigdor Finkelstein.)
3790 Changes affecting code
3792 A uninitialized-storage bug in 'localtime' has been fixed.
3793 (Thanks to Logan Chien.)
3795 Changes affecting the build procedure
3797 The settings for 'make check_web' now default to Ubuntu 13.10.
3799 Changes affecting commentary and documentation
3801 The boundary of the US Pacific time zone is given more accurately.
3802 (Thanks to Alan Mintz.)
3804 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3806 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3808 Better descriptions of countries with same time zone history as
3809 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3811 Several changes affect tz-link.htm, the main web page.
3813 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3816 Mention xCal (Internet RFC 6321) and jCal.
3818 Microsoft has some support for tz database names.
3820 CLDR data formats include both XML and JSON.
3822 Mention Maggiolo's map of solar vs standard time.
3823 (Thanks to Arthur David Olson.)
3825 Mention TZ4Net. (Thanks to Matt Johnson.)
3827 Mention the timezone-olson Haskell package.
3829 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3831 Remove moribund links to daylight-savings-time.info and to
3832 Simple Timer + Clocks.
3834 Update two links. (Thanks to Oscar van Vlijmen.)
3836 Fix some formatting glitches, e.g., remove random newlines from
3837 abbr elements' title attributes.
3840 Release 2013i - 2013-12-17 07:25:23 -0800
3842 Changes affecting near-future timestamps:
3844 Jordan switches back to standard time at 00:00 on December 20, 2013.
3845 The 2006-2011 transition schedule is planned to resume in 2014.
3846 (Thanks to Steffen Thorsen.)
3848 Changes affecting past timestamps:
3850 In 2004, Cuba began DST on March 28, not April 4.
3851 (Thanks to Steffen Thorsen.)
3853 Changes affecting code
3855 The compile-time flag NOSOLAR has been removed, as nowadays the
3856 benefit of slightly shrinking runtime table size is outweighed by the
3857 cost of disallowing potential future updates that exceed old limits.
3859 Changes affecting documentation and commentary
3861 The files solar87, solar88, and solar89 are no longer distributed.
3862 They were a negative experiment - that is, a demonstration that
3863 tz data can represent solar time only with some difficulty and error.
3864 Their presence in the distribution caused confusion, as Riyadh
3865 civil time was generally not solar time in those years.
3867 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3870 Release 2013h - 2013-10-25 15:32:32 -0700
3872 Changes affecting current and future timestamps:
3874 Libya has switched its UT offset back to +02 without DST, instead
3875 of +01 with DST. (Thanks to Even Scharning.)
3877 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3878 (Thanks to Gwillim Law.)
3880 Changes affecting future timestamps:
3882 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3883 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3884 (Thanks to Steffen Thorsen.)
3886 Add entries for DST transitions in Morocco in the year 2038.
3887 This avoids some year-2038 glitches introduced in 2013g.
3888 (Thanks to Yoshito Umaoka for reporting the problem.)
3890 Changes affecting API
3892 The 'tzselect' command no longer requires the 'select' command,
3893 and should now work with /bin/sh on more platforms. It also works
3894 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3895 Patrick 'P. J.' McDermott and Alan Barrett.)
3897 Changes affecting code
3899 Fix localtime overflow bugs with 32-bit unsigned time_t.
3901 zdump no longer assumes sscanf returns maximal values on overflow.
3903 Changes affecting the build procedure
3905 The builder can specify which programs to use, if any, instead of
3906 'ar' and 'ranlib', and libtz.a is now built locally before being
3907 installed. (Thanks to Michael Forney.)
3909 A dependency typo in the 'zdump' rule has been fixed.
3910 (Thanks to Andrew Paprocki.)
3912 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3913 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3915 'make clean' no longer removes 'leapseconds', since it's
3916 host-independent and is part of the distribution.
3918 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3920 Changes affecting documentation and commentary
3922 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3923 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3925 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3926 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3927 longer maintained) and for old advisories. SOFA now does C.
3929 Release 2013g - 2013-09-30 21:08:26 -0700
3931 Changes affecting current and near-future timestamps
3933 Morocco now observes DST from the last Sunday in March to the last
3934 Sunday in October, not April to September respectively. (Thanks
3935 to Steffen Thorsen.)
3937 Changes affecting 'zic'
3939 'zic' now runs on platforms that lack both hard links and symlinks.
3940 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3941 Also, fix some bugs on platforms that lack hard links but have symlinks.
3943 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3944 to predict the far future, fixing a bug introduced in 2013e.
3946 Changes affecting the build procedure
3948 The 'leapseconds' file is again put into the tzdata tarball.
3949 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3950 Matt Burgess and Ian Abbott.) The timestamps of these and other
3951 dependent files in tarballs are adjusted more consistently.
3953 Changes affecting documentation and commentary
3955 The README file is now part of the data tarball as well as the code.
3956 It now states that files are public domain unless otherwise specified.
3957 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3958 Its details about the 1989 release moved to a place of honor near
3962 Release 2013f - 2013-09-24 23:37:36 -0700
3964 Changes affecting near-future timestamps
3966 Tocantins will very likely not observe DST starting this spring.
3967 (Thanks to Steffen Thorsen.)
3969 Jordan will likely stay at UT +03 indefinitely, and will not fall
3972 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3974 Changes affecting API
3976 The types of the global variables 'timezone' and 'altzone' (if present)
3977 have been changed back to 'long'. This is required for 'timezone'
3978 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3979 These variables were originally 'long' in the tz code, but were
3980 mistakenly changed to 'time_t' in 1987; nobody reported the
3981 incompatibility until now. The difference matters on x32, where
3982 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3984 Changes affecting the build procedure
3986 Avoid long strings in leapseconds.awk to work around a mawk bug.
3987 (Thanks to Cyril Baurand.)
3989 Changes affecting documentation and commentary
3991 New file 'NEWS' that contains release notes like this one.
3993 Paraguay's law does not specify DST transition time; 00:00 is customary.
3994 (Thanks to Waldemar Villamayor-Venialbo.)
3996 Minor capitalization fixes.
3998 Changes affecting version-control only
4000 The experimental GitHub repository now contains annotated and
4001 signed tags for recent releases, e.g., '2013e' for Release 2013e.
4002 Releases are tagged starting with 2012e; earlier releases were
4003 done differently, and tags would either not have a simple name or
4004 not exactly match what was released.
4006 'make set-timestamps' is now simpler and a bit more portable.
4009 Release 2013e - 2013-09-19 23:50:04 -0700
4011 Changes affecting near-future timestamps
4013 This year Fiji will start DST on October 27, not October 20.
4014 (Thanks to David Wheeler for the heads-up.) For now, guess that
4015 Fiji will continue to spring forward the Sunday before the fourth
4018 Changes affecting current and future time zone abbreviations
4020 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
4021 time zone abbreviations since 1932. (Thanks to George Ziegler,
4022 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
4023 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
4024 Asia/Makassar, and Asia/Pontianak.
4026 Use ART (UT -03, standard time), rather than WARST (also -03, but
4027 daylight saving time) for San Luis, Argentina since 2009.
4029 Changes affecting Godthåb timestamps after 2037 if version mismatch
4031 Allow POSIX-like TZ strings where the transition time's hour can
4032 range from -167 through 167, instead of the POSIX-required 0
4033 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
4034 new Fiji rules. This is a more compact way to represent
4035 far-future timestamps for America/Godthab, America/Santiago,
4036 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
4037 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
4038 this change. (Derived from a suggestion by Arthur David Olson.)
4040 Allow POSIX-like TZ strings where daylight saving time is in
4041 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
4042 Argentina Summer Time all year. This supports a more compact way
4043 to represent the 2013d data for America/Argentina/San_Luis.
4044 Because of the change for San Luis noted above this change does not
4045 affect the current data. (Thanks to Andrew Main (Zefram) for
4046 suggestions that improved this change.)
4048 Where these two TZ changes take effect, there is a minor extension
4049 to the tz file format in that it allows new values for the
4050 embedded TZ-format string, and the tz file format version number
4051 has therefore been increased from 2 to 3 as a precaution.
4052 Version-2-based client code should continue to work as before for
4053 all timestamps before 2038. Existing version-2-based client code
4054 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
4055 files, and typically works in practice even for timestamps after
4056 2037; the only known exception is America/Godthab.
4058 Changes affecting timestamps before 1970
4060 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
4061 some errors before 1947.
4063 Some zones have been turned into links, when they differ from existing
4064 zones only in older data entries that were likely invented or that
4065 differ only in LMT or transitions from LMT. These changes affect
4066 only timestamps before 1943. The affected zones are:
4067 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
4068 America/Grenada, America/Guadeloupe, America/Marigot,
4069 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
4070 America/St_Lucia, America/St_Thomas, America/St_Vincent,
4071 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
4072 confirming that the old Europe/Vaduz zone was wrong and the new
4073 link is better for WWII-era times.)
4075 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
4076 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
4079 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
4080 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
4083 Change the date of the circa-1850 Zurich transition from 1849-09-12
4084 to 1853-07-16, overriding Shanks with data from Messerli about
4085 postal and telegraph time in Switzerland.
4087 Changes affecting time zone abbreviations before 1970
4089 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
4090 as Jakarta was called Batavia back then.
4092 Changes affecting API
4094 The 'zic' command now outputs a dummy transition when far-future
4095 data can't be summarized using a TZ string, and uses a 402-year
4096 window rather than a 400-year window. For the current data, this
4097 affects only the Asia/Tehran file. It does not affect any of the
4098 timestamps that this file represents, so zdump outputs the same
4099 information as before. (Thanks to Andrew Main (Zefram).)
4101 The 'date' command has a new '-r' option, which lets you specify
4102 the integer time to display, a la FreeBSD.
4104 The 'tzselect' command has two new options '-c' and '-n', which lets you
4105 select a zone based on latitude and longitude.
4107 The 'zic' command's '-v' option now warns about constructs that
4108 require the new version-3 binary file format. (Thanks to Arthur
4109 David Olson for the suggestion.)
4111 Support for floating-point time_t has been removed.
4112 It was always dicey, and POSIX no longer requires it.
4113 (Thanks to Eric Blake for suggesting to the POSIX committee to
4114 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
4115 Heninger, Arthur David Olson, and Alois Treindl, for reporting
4116 bugs and elucidating some of the corners of the old floating-point
4119 The signatures of 'offtime', 'timeoff', and 'gtime' have been
4120 changed back to the old practice of using 'long' to represent UT
4121 offsets. This had been inadvertently and mistakenly changed to
4122 'int_fast32_t'. (Thanks to Christos Zoulas.)
4124 The code avoids undefined behavior on integer overflow in some
4125 more places, including gmtime, localtime, mktime and zdump.
4127 Changes affecting the zdump utility
4129 zdump now outputs "UT" when referring to Universal Time, not "UTC".
4130 "UTC" does not make sense for timestamps that predate the introduction
4131 of UTC, whereas "UT", a more generic term, does. (Thanks to Steve Allen
4132 for clarifying UT vs UTC.)
4134 Data changes affecting behavior of tzselect and similar programs
4136 Country code BQ is now called the more common name "Caribbean Netherlands"
4137 rather than the more official "Bonaire, St Eustatius & Saba".
4139 Remove from zone.tab the names America/Montreal, America/Shiprock,
4140 and Antarctica/South_Pole, as they are equivalent to existing
4141 same-country-code zones for post-1970 timestamps. The data entries for
4142 these names are unchanged, so the names continue to work as before.
4144 Changes affecting code internals
4146 zic -c now runs way faster on 64-bit hosts when given large numbers.
4148 zic now uses vfprintf to avoid allocating and freeing some memory.
4150 tzselect now computes the list of continents from the data,
4151 rather than have it hard-coded.
4153 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
4155 Changes affecting the build procedure
4157 The 'leapseconds' file is now generated automatically from a
4158 new file 'leap-seconds.list', which is a copy of
4159 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
4160 A new source file 'leapseconds.awk' implements this.
4161 The goal is simplification of the future maintenance of 'leapseconds'.
4163 When building the 'posix' or 'right' subdirectories, if the
4164 subdirectory would be a copy of the default subdirectory, it is
4165 now made a symbolic link if that is supported. This saves about
4166 2 MB of file system space.
4168 The links America/Shiprock and Antarctica/South_Pole have been
4169 moved to the 'backward' file. This affects only nondefault builds
4170 that omit 'backward'.
4172 Changes affecting version-control only
4174 .gitignore now ignores 'date'.
4176 Changes affecting documentation and commentary
4178 Changes to the 'tzfile' man page
4180 It now mentions that the binary file format may be extended in
4181 future versions by appending data.
4183 It now refers to the 'zdump' and 'zic' man pages.
4185 Changes to the 'zic' man page
4187 It lists conditions that elicit a warning with '-v'.
4189 It says that the behavior is unspecified when duplicate names
4190 are given, or if the source of one link is the target of another.
4192 Its examples are updated to match the latest data.
4194 The definition of white space has been clarified slightly.
4195 (Thanks to Michael Deckers.)
4197 Changes to the 'Theory' file
4199 There is a new section about the accuracy of the tz database,
4200 describing the many ways that errors can creep in, and
4201 explaining why so many of the pre-1970 timestamps are wrong or
4202 misleading (thanks to Steve Allen, Lester Caine, and Garrett
4203 Wollman for discussions that contributed to this).
4205 The 'Theory' file describes LMT better (this follows a
4206 suggestion by Guy Harris).
4208 It refers to the 2013 edition of POSIX rather than the 2004 edition.
4210 It's mentioned that excluding 'backward' should not affect the
4211 other data, and it suggests at least one zone.tab name per
4212 inhabited country (thanks to Stephen Colebourne).
4214 Some longstanding restrictions on names are documented, e.g.,
4215 'America/New_York' precludes 'America/New_York/Bronx'.
4217 It gives more reasons for the 1970 cutoff.
4219 It now mentions which time_t variants are supported, such as
4220 signed integer time_t. (Thanks to Paul Goyette for reporting
4221 typos in an experimental version of this change.)
4223 (Thanks to Philip Newton for correcting typos in these changes.)
4225 Documentation and commentary is more careful to distinguish UT in
4226 general from UTC in particular. (Thanks to Steve Allen.)
4228 Add a better source for the Zurich 1894 transition.
4229 (Thanks to Pierre-Yves Berger.)
4231 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
4234 Release 2013d - 2013-07-05 07:38:01 -0700
4236 Changes affecting future timestamps:
4238 Morocco's midsummer transitions this year are July 7 and August 10,
4239 not July 9 and August 8. (Thanks to Andrew Paprocki.)
4241 Israel now falls back on the last Sunday of October.
4242 (Thanks to Ephraim Silverberg.)
4244 Changes affecting past timestamps:
4246 Specify Jerusalem's location more precisely; this changes the pre-1880
4249 Changing affecting metadata only:
4251 Fix typos in the entries for country codes BQ and SX.
4253 Changes affecting code:
4255 Rework the code to fix a bug with handling Australia/Macquarie on
4256 32-bit hosts (thanks to Arthur David Olson).
4258 Port to platforms like NetBSD, where time_t can be wider than long.
4260 Add support for testing time_t types other than the system's.
4261 Run 'make check_time_t_alternatives' to try this out.
4262 Currently, the tests fail for unsigned time_t;
4263 this should get fixed at some point.
4265 Changes affecting documentation and commentary:
4267 Deemphasize the significance of national borders.
4269 Update the zdump man page.
4271 Remove obsolete NOID comment (thanks to Denis Excoffier).
4273 Update several URLs and comments in the web pages.
4275 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
4277 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
4280 Release 2013c - 2013-04-19 16:17:40 -0700
4282 Changes affecting current and future timestamps:
4284 Palestine observed DST starting March 29, 2013. (Thanks to
4285 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
4286 with the predicted rules being the last Thursday in March at 24:00
4287 to the first Friday on or after September 21 at 01:00.
4289 Assume that the recent change to Paraguay's DST rules is permanent,
4290 by moving the end of DST to the 4th Sunday in March every year.
4291 (Thanks to Carlos Raúl Perasso.)
4293 Changes affecting past timestamps:
4295 Fix some historical data for Palestine to agree with that of
4296 timeanddate.com, as follows:
4298 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
4301 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
4304 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
4306 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
4308 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
4310 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
4312 Fix times of habitation for Macquarie to agree with the Tasmania
4313 Parks & Wildlife Service history, which indicates that permanent
4314 habitation was 1899-1919 and 1948 on.
4316 Changing affecting metadata only:
4318 Macquarie Island is politically part of Australia, not Antarctica.
4319 (Thanks to Tobias Conradi.)
4321 Sort Macquarie more consistently with other parts of Australia.
4322 (Thanks to Tim Parenti.)
4325 Release 2013b - 2013-03-10 22:33:40 -0700
4327 Changes affecting current and future timestamps:
4329 Haiti uses US daylight-saving rules this year, and presumably future years.
4330 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
4332 Paraguay will end DST on March 24 this year.
4333 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
4335 Morocco does not observe DST during Ramadan;
4336 try to predict Ramadan in Morocco as best we can.
4337 (Thanks to Erik Homoet for the heads-up.)
4339 Changes affecting commentary:
4341 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
4342 Update URL for Solaris. Mention Internet RFC 6557.
4343 Update Internet RFCs 2445->5545, 2822->5322.
4344 Switch from FTP to HTTP for Internet RFCs.
4347 Release 2013a - 2013-02-27 09:20:35 -0800
4349 Change affecting binary data format:
4351 The zone offset at the end of version-2-format zone files is now
4352 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
4354 Changes affecting current and future timestamps:
4356 Chile's 2013 rules, and we guess rules for 2014 and later, will be
4357 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
4358 (Thanks to Steffen Thorsen and Robert Elz.)
4360 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
4361 (Thanks to Tobias Conradi and Arthur David Olson.)
4363 Many changes affect historical timestamps before 1940.
4364 These were deduced from: Milne J. Civil time. Geogr J. 1899
4365 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
4367 Changes affecting the code:
4369 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
4370 the data). (Thanks to Arthur David Olson.)
4372 Fix localtime bug when time_t is unsigned and data files were generated
4373 by a signed time_t system. (Thanks to Doug Bailey for reporting and
4374 to Arthur David Olson for fixing.)
4376 Allow the email address for bug reports to be set by the packager.
4377 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
4379 Update HTML checking to be compatible with Ubuntu 12.10.
4381 Check that files are a safe subset of ASCII. At some point we may
4382 relax this requirement to a safe subset of UTF-8. Without the
4383 check, some non-UTF-8 encodings were leaking into the distribution.
4387 Restore a comment about copyright notices that was inadvertently deleted.
4388 (Thanks to Arthur David Olson.)
4390 Improve the commentary about which districts observe what times
4391 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
4393 Add web page links to tz.js.
4395 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
4398 Release 2012j - 2012-11-12 18:34:49 -0800
4400 Libya moved to CET this weekend, but with DST planned next year.
4401 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
4403 Signatures now have the extension .asc, not .sign, as that's more
4404 standard. (Thanks to Phil Pennock.)
4406 The output of 'zdump --version', and of 'zic --version', now
4407 uses a format that is more typical for --version.
4408 (Thanks to Joseph S. Myers.)
4410 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
4411 now uses tz@iana.org rather than the old elsie address.
4413 zic -v now complains about abbreviations that are less than 3
4414 or more than 6 characters, as per POSIX. Formerly, it checked
4415 for abbreviations that were more than 3.
4417 'make public' no longer puts its temporary directory under /tmp,
4418 and uses the just-built zic rather than the system zic.
4420 Various fixes to documentation and commentary.
4423 Release 2012i - 2012-11-03 12:57:09 -0700
4425 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
4427 Linker flags can now be specified via LDFLAGS.
4428 AWK now defaults to 'awk', not 'nawk'.
4429 The shell in tzselect now defaults to /bin/bash, but this can
4430 be overridden by specifying KSHELL.
4431 The main web page now mentions the unofficial GitHub repository.
4432 (Thanks to Mike Frysinger.)
4434 Tarball signatures can now be built by running 'make signatures'.
4435 There are also new makefile rules 'tarballs', 'check_public', and
4436 separate makefile rules for each tarball and signature file.
4437 A few makefile rules are now more portable to strict POSIX.
4439 The main web page now lists the canonical IANA URL.
4442 Release 2012h - 2012-10-26 22:49:10 -0700
4444 Bahia no longer has DST. (Thanks to Kelley Cook.)
4446 Tocantins has DST. (Thanks to Rodrigo Severo.)
4448 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
4450 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
4454 More C modernization, except that at Arthur David Olson's suggestion
4455 the instances of 'register' were kept.
4458 Release 2012g - 2012-10-17 20:59:45 -0700
4460 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
4462 Palestine fall 2012. (Thanks to Steffen Thorsen.)
4466 To attack the version-number problem, this release ships the file
4467 'Makefile' (which contains the release number) in both the tzcode and
4468 the tzdata tarballs. The two Makefiles are identical, and should be
4469 identical in any matching pair of tarballs, so it shouldn't matter
4470 which order you extract the tarballs. Perhaps we can come up with a
4471 better version-number scheme at some point; this scheme does have the
4472 virtue of not adding more files.
4475 Release 2012f - 2012-09-12 23:17:03 -0700
4477 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4478 20 this year. (Thanks to Steffen Thorsen.)
4481 Release 2012e - 2012-08-02 20:44:55 -0700
4483 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4484 (Thanks to Steffen Thorsen.)
4486 * Use a single version number for both code and data.
4488 * .gitignore: New file.
4490 * Remove trailing white space.
4493 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4495 Changes for Morocco's timestamps, which take effect in a couple of
4496 hours, along with infrastructure changes to accommodate how the tz
4497 code and data are released on IANA.
4500 Release data2012c - 2012-03-27 12:17:25 -0400
4503 Summer time changes for Morocco (to start late April 2012)
4506 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4509 Haiti following US/Canada rules for 2012 (and we're assuming,
4510 for now anyway, for the future).
4513 Release 2012b - 2012-03-02 12:29:15 +0700
4515 There is just one change to tzcode2012b (compared with 2012a):
4516 the Makefile that was accidentally included with 2012a has been
4517 replaced with the version that should have been there, which is
4518 identical with the previous version (from tzcode2011i).
4520 There are just two changes in tzdata2012b compared with 2012a.
4522 Most significantly, summer time in Cuba has been delayed 3 weeks
4523 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4524 date, as listed in 2012a) is just a little over a week away, this
4527 Less importantly, an excess tab in one of the changes in zone.tab
4528 in 2012a has been removed.
4531 Release 2012a - 2012-03-01 18:28:10 +0700
4533 The changes in tzcode2012a (compared to the previous version, 2011i)
4534 are entirely to the README and tz-art.htm and tz-link.htm files, if
4535 none of those concern you, you can ignore the code update. The changes
4536 reflect the changed addresses for the mailing list and the code and
4537 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4538 has been added to tz-link.htm).
4540 In tzdata2012a (compared to the previous release, which was 2011n)
4541 the major changes are:
4542 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4543 Falkland Islands onto permanent summer time (we're assuming for the
4544 foreseeable future, though 2012 is all we're fairly certain of.)
4545 Armenia has abolished Summer Time.
4546 Tokelau jumped the International Date Line back last December
4547 (just the same as their near neighbour, Samoa).
4548 America/Creston is a new zone for a small area of British Columbia
4549 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4551 Other minor changes are:
4552 Corrections to 1918 Canadian summer time end dates.
4553 Updated URL for UK time zone history (in comments)
4554 A few typos in Le Corre's list of free French place names (comments)
4557 Release data2011n - 2011-10-30 14:57:54 +0700
4559 There are three changes of note - most urgently, Cuba (America/Havana)
4560 has extended summer time by two weeks, now to end on Nov 13, rather than
4561 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4562 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4563 all, and consequently that zone has been removed (again) and reinstated
4564 in the "backward" file as a link to Europe/Chisinau. And third, the
4565 end date for Fiji's summer time this summer was moved forward from the
4566 earlier planned Feb 26, to Jan 22.
4568 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4569 (and the incorrect syntax that was in the 2011m version of that file
4570 is so fixed - it would have been fixed in a different way had this
4571 change not happened - that's the "missing" sccs version id).
4574 Release data2011m - 2011-10-24 21:42:16 +0700
4576 In particular, the typos in comments in the data (2011-11-17 should have
4577 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4578 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4579 made in all 4 Ukrainian zones, rather than just Europe/Kiev
4580 (again, thanks to Tim Parenti, and also Denys Gavrysh).
4582 In addition, I added Europe/Tiraspol to zone.tab.
4584 This time, all the files have new version numbers... (including the files
4585 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4586 version numbers there...)
4589 Release data2011l - 2011-10-10 11:15:43 +0700
4591 There are just 2 changes that cause different generated tzdata files from
4592 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4593 is included, but commented out. Compared with the diff I sent out last week,
4594 this version also includes attributions for the sources for the changes
4595 (in much the same format as ado used, but the html tags have not been
4596 checked, verified, or used in any way at all, so if there are errors there,
4597 please let me know.)
4600 Release data2011k - 2011-09-20 17:54:03 -0400
4605 Release data2011j - 2011-09-12 09:22:49 -0400
4607 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4608 Tanzania); there are also two spelling corrections to comments in
4609 the australasia file (with thanks to Christos Zoulas).
4612 Release 2011i - 2011-08-29 05:56:32 -0400
4617 Release data2011h - 2011-06-15 18:41:48 -0400
4619 Russia and Curaçao changes
4622 Release 2011g - 2011-04-25 09:07:22 -0400
4624 update the rules for Egypt to reflect its abandonment of DST this year
4627 Release 2011f - 2011-04-06 17:14:53 -0400
4632 Release 2011e - 2011-03-31 16:04:38 -0400
4634 Morocco, Chile, and tz-link changes
4637 Release 2011d - 2011-03-14 09:18:01 -0400
4639 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4642 Release 2011c - 2011-03-07 09:30:09 -0500
4644 These do affect current timestamps in Chile and Annette Island, Canada.
4647 Release 2011b - 2011-02-07 08:44:50 -0500
4652 Release 2011a - 2011-01-24 10:30:16 -0500
4657 Release data2010o - 2010-11-01 09:18:23 -0400
4659 change to the end of DST in Fiji in 2011
4662 Release 2010n - 2010-10-25 08:19:17 -0400
4667 Release 2010m - 2010-09-27 09:24:48 -0400
4669 Hong Kong, Vostok, and zic.c changes
4672 Release 2010l - 2010-08-16 06:57:25 -0400
4677 Release 2010k - 2010-07-26 10:42:27 -0400
4682 Release 2010j - 2010-05-10 09:07:48 -0400
4684 changes for Bahía de Banderas and for version naming
4687 Release data2010i - 2010-04-16 18:50:45 -0400
4689 the end of DST in Morocco on 2010-08-08
4692 Release data2010h - 2010-04-05 09:58:56 -0400
4697 Release data2010g - 2010-03-24 11:14:53 -0400
4702 Release 2010f - 2010-03-22 09:45:46 -0400
4707 Release data2010e - 2010-03-08 14:24:27 -0500
4709 corrects the Dhaka bug found by Danvin Ruangchan
4712 Release data2010d - 2010-03-06 07:26:01 -0500
4717 Release 2010c - 2010-03-01 09:20:58 -0500
4719 changes including KRE's suggestion for earlier initialization of
4720 "goahead" and "goback" structure elements
4723 Release code2010a - 2010-02-16 10:40:04 -0500
4728 Release data2010b - 2010-01-20 12:37:01 -0500
4733 Release data2010a - 2010-01-18 08:30:04 -0500
4738 Release data2009u - 2009-12-26 08:32:28 -0500
4740 changes to DST in Bangladesh
4743 Release 2009t - 2009-12-21 13:24:27 -0500
4748 Release data2009s - 2009-11-14 10:26:32 -0500
4750 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4753 Release 2009r - 2009-11-09 10:10:31 -0500
4755 "antarctica" and "tz-link.htm" changes
4758 Release 2009q - 2009-11-02 09:12:40 -0500
4760 with two corrections as reported by Eric Muller and Philip Newton
4763 Release data2009p - 2009-10-23 15:05:27 -0400
4765 Argentina (including San Luis) changes (with the correction from
4769 Release data2009o - 2009-10-14 16:49:38 -0400
4771 Samoa (commentary only), Pakistan, and Bangladesh changes
4774 Release data2009n - 2009-09-22 15:13:38 -0400
4776 added commentary for Argentina and a change to the end of DST in
4780 Release data2009m - 2009-09-03 10:23:43 -0400
4782 Samoa and Palestine changes
4785 Release data2009l - 2009-08-14 09:13:07 -0400
4787 Samoa (comments only) and Egypt
4790 Release 2009k - 2009-07-20 09:46:08 -0400
4795 Release data2009j - 2009-06-15 06:43:59 -0400
4797 Bangladesh change (with a short turnaround since the DST change is
4801 Release 2009i - 2009-06-08 09:21:22 -0400
4803 updating for DST in Bangladesh this year
4806 Release 2009h - 2009-05-26 09:19:14 -0400
4811 Release data2009g - 2009-04-20 16:34:07 -0400
4816 Release data2009f - 2009-04-10 11:00:52 -0400
4818 correct DST in Pakistan
4821 Release 2009e - 2009-04-06 09:08:11 -0400
4826 Release 2009d - 2009-03-23 09:38:12 -0400
4828 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4831 Release data2009c - 2009-03-16 09:47:51 -0400
4833 change to the start of Cuban DST
4836 Release 2009b - 2009-02-09 11:15:22 -0500
4841 Release 2009a - 2009-01-21 10:09:39 -0500
4846 Release data2008i - 2008-10-21 12:10:25 -0400
4848 southamerica and zone.tab files, with Argentina DST rule changes and
4849 United States zone reordering and recommenting
4852 Release 2008h - 2008-10-13 07:33:56 -0400
4857 Release 2008g - 2008-10-06 09:03:18 -0400
4859 Fix a broken HTML anchor and update Brazil's DST transitions;
4860 there's also a slight reordering of information in tz-art.htm.
4863 Release data2008f - 2008-09-09 22:33:26 -0400
4868 Release 2008e - 2008-07-28 14:11:17 -0400
4870 changes by Arthur David Olson and Jesper Nørgaard Welen
4873 Release data2008d - 2008-07-07 09:51:38 -0400
4875 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4878 Release data2008c - 2008-05-19 17:48:03 -0400
4880 Pakistan, Morocco, and Mongolia
4883 Release data2008b - 2008-03-24 08:30:59 -0400
4885 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4889 Release 2008a - 2008-03-08 05:42:16 -0500
4894 Release 2007k - 2007-12-31 10:25:22 -0500
4896 most importantly, changes to the "southamerica" file based on
4897 Argentina's readoption of daylight saving time
4900 Release 2007j - 2007-12-03 09:51:01 -0500
4902 1. eliminate the "P" (parameter) macro;
4904 2. the "noncontroversial" changes circulated on the time zone
4905 mailing list (less the changes to "logwtmp.c");
4907 3. eliminate "too many transition" errors when "min" is used in time
4910 4. changes by Paul Eggert (including updated information for Venezuela).
4913 Release data2007i - 2007-10-30 10:28:11 -0400
4915 changes for Cuba and Syria
4918 Release 2007h - 2007-10-01 10:05:51 -0400
4920 changes by Paul Eggert, as well as an updated link to the ICU
4921 project in tz-link.htm
4924 Release 2007g - 2007-08-20 10:47:59 -0400
4926 changes by Paul Eggert
4928 The "leapseconds" file has been updated to incorporate the most
4929 recent International Earth Rotation and Reference Systems Service
4932 There's an addition to tz-art.htm regarding the television show "Medium".
4935 Release 2007f - 2007-05-07 10:46:46 -0400
4937 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4940 changes to zic.c to allow hour values greater than 24 (along with
4941 Paul's improved time value overflow checking)
4944 Release 2007e - 2007-04-02 10:11:52 -0400
4946 Syria and Honduras changes by Paul Eggert
4948 zic.c variable renaming changes by Arthur David Olson
4951 Release 2007d - 2007-03-20 08:48:30 -0400
4953 changes by Paul Eggert
4955 the elimination of white space at the ends of lines
4958 Release 2007c - 2007-02-26 09:09:37 -0500
4960 changes by Paul Eggert
4963 Release 2007b - 2007-02-12 09:34:20 -0500
4965 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4967 changes to the commentary in "leapseconds" reflecting the IERS
4968 announcement that there is to be no positive leap second at the end
4972 Release 2007a - 2007-01-08 12:28:29 -0500
4974 changes by Paul Eggert
4976 Derick Rethans's Asmara change
4978 Oscar van Vlijmen's Easter Island local mean time change
4980 symbolic link changes
4983 Release 2006p - 2006-11-27 08:54:27 -0500
4985 changes by Paul Eggert
4988 Release 2006o - 2006-11-06 09:18:07 -0500
4990 changes by Paul Eggert
4993 Release 2006n - 2006-10-10 11:32:06 -0400
4995 changes by Paul Eggert
4998 Release 2006m - 2006-10-02 15:32:35 -0400
5000 changes for Uruguay, Palestine, and Egypt by Paul Eggert
5002 (minimalist) changes to zic.8 to clarify "until" information
5005 Release data2006l - 2006-09-18 12:58:11 -0400
5007 Paul's best-effort work on this coming weekend's Egypt time change
5010 Release 2006k - 2006-08-28 12:19:09 -0400
5012 changes by Paul Eggert
5015 Release 2006j - 2006-08-21 09:56:32 -0400
5017 changes by Paul Eggert
5020 Release code2006i - 2006-08-07 12:30:55 -0400
5024 Ken Pizzini's conversion script
5027 Release code2006h - 2006-07-24 09:19:37 -0400
5029 adds public domain notices to four files
5031 includes a fix for transition times being off by a second
5033 adds a new recording to the "arts" file (information courtesy Colin Bowern)
5036 Release 2006g - 2006-05-08 17:18:09 -0400
5038 northamerica changes by Paul Eggert
5041 Release 2006f - 2006-05-01 11:46:00 -0400
5043 a missing version number problem is fixed (with thanks to Bradley
5044 White for catching the problem)
5047 Release 2006d - 2006-04-17 14:33:43 -0400
5049 changes by Paul Eggert
5051 added new items to tz-arts.htm that were found by Paul
5054 Release 2006c - 2006-04-03 10:09:32 -0400
5056 two sets of data changes by Paul Eggert
5058 a fencepost error fix in zic.c
5060 changes to zic.c and the "europe" file to minimize differences
5061 between output produced by the old 32-bit zic and the new 64-bit
5065 Release 2006b - 2006-02-20 10:08:18 -0500
5066 [tz32code2006b + tz64code2006b + tzdata2006b]
5070 All SCCS IDs were bumped to "8.1" for this release.
5073 Release 2006a - 2006-01-30 08:59:31 -0500
5075 changes by Paul Eggert (in particular, Indiana time zone moves)
5077 an addition to the zic manual page to describe how special-case
5078 transitions are handled
5081 Release 2005r - 2005-12-27 09:27:13 -0500
5083 Canadian changes by Paul Eggert
5085 They also add "<pre>" directives to time zone data files and reflect
5086 changes to warning message logic in "zdump.c" (but with calls to
5087 "gettext" kept unbundled at the suggestion of Ken Pizzini).
5090 Release 2005q - 2005-12-13 09:17:09 -0500
5092 Nothing earth-shaking here:
5093 1. Electronic mail addresses have been removed.
5094 2. Casts of the return value of exit have been removed.
5095 3. Casts of the argument of is.* macros have been added.
5096 4. Indentation in one section of zic.c has been fixed.
5097 5. References to dead URLs in the data files have been dealt with.
5100 Release 2005p - 2005-12-05 10:30:53 -0500
5102 "systemv", "tz-link.htm", and "zdump.c" changes
5103 (less the casts of arguments to the is* macros)
5106 Release 2005o - 2005-11-28 10:55:26 -0500
5108 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
5110 zdump.c lint fixes by Arthur David Olson
5113 Release 2005n - 2005-10-03 09:44:09 -0400
5115 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
5119 Release 2005m - 2005-08-29 12:15:40 -0400
5121 changes by Paul Eggert (with a small tweak to the tz-art change)
5123 a declaration of an unused variable has been removed from zdump.c
5126 Release 2005l - 2005-08-22 12:06:39 -0400
5128 changes by Paul Eggert
5130 overflow/underflow checks by Arthur David Olson, minus changes to
5131 the "Theory" file about the pending addition of 64-bit data (I grow
5132 less confident of the changes being accepted with each passing day,
5133 and the changes no longer increase the data files nine-fold--there's
5134 less than a doubling in size by my local Sun's reckoning)
5137 Release 2005k - 2005-07-14 14:14:24 -0400
5139 The "leapseconds" file has been edited to reflect the recently
5140 announced leap second at the end of 2005.
5142 I've also deleted electronic mail addresses from the files as an
5146 Release 2005j - 2005-06-13 14:34:13 -0400
5148 These reflect changes to limit the length of time zone abbreviations
5149 and the characters used in those abbreviations.
5151 There are also changes to handle POSIX-style "quoted" timezone
5152 environment variables.
5154 The changes were circulated on the time zone mailing list; the only
5155 change since then was the removal of a couple of minimum-length of
5156 abbreviation checks.
5159 Release data2005i - 2005-04-21 15:04:16 -0400
5161 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
5164 Release 2005h - 2005-04-04 11:24:47 -0400
5166 changes by Paul Eggert
5168 minor changes to Makefile and zdump.c to produce more useful output
5169 when doing a "make typecheck"
5172 Release 2005g - 2005-03-14 10:11:21 -0500
5174 changes by Paul Eggert (a change to current DST rules in Uruguay and
5175 an update to a link to time zone software)
5178 Release 2005f - 2005-03-01 08:45:32 -0500
5180 data and documentation changes by Paul Eggert
5183 Release 2005e - 2005-02-10 15:59:44 -0500
5188 Release code2005d - 2005-01-31 09:21:47 -0500
5190 make zic complain about links to links if the -v flag is used
5192 have "make public" do more code checking
5194 add an include to "localtime.c" for the benefit of gcc systems
5197 Release 2005c - 2005-01-17 18:36:29 -0500
5199 get better results when mktime runs on a system where time_t is double
5201 changes to the data files (most importantly to Paraguay)
5204 Release 2005b - 2005-01-10 09:19:54 -0500
5206 Get localtime and gmtime working on systems with exotic time_t types.
5208 Update the leap second commentary in the "leapseconds" file.
5211 Release 2005a - 2005-01-01 13:13:44 -0500
5216 Release code2004i - 2004-12-14 13:42:58 -0500
5218 Deal with systems where time_t is unsigned.
5221 Release code2004h - 2004-12-07 11:40:18 -0500
5223 64-bit-time_t changes
5226 Release 2004g - 2004-11-02 09:06:01 -0500
5228 update to Cuba (taking effect this weekend)
5230 other changes by Paul Eggert
5232 correction of the spelling of Oslo
5234 changed versions of difftime.c and private.h
5237 Release code2004f - 2004-10-21 10:25:22 -0400
5239 Cope with wide-ranging tm_year values.
5242 Release 2004e - 2004-10-11 14:47:21 -0400
5244 Brazil/Argentina/Israel changes by Paul Eggert
5246 changes to tz-link.htm by Paul
5248 one small fix to Makefile
5251 Release 2004d - 2004-09-22 08:27:29 -0400
5253 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
5256 Release 2004c - 2004-08-11 12:06:26 -0400
5258 asctime-related changes
5260 (variants of) some of the documentation changes suggested by Paul Eggert
5263 Release 2004b - 2004-07-19 14:33:35 -0400
5265 data changes by Paul Eggert - most importantly, updates for Argentina
5268 Release 2004a - 2004-05-27 12:00:47 -0400
5270 changes by Paul Eggert
5272 Handle DST transitions that occur at the end of a month in some
5273 years but at the start of the following month in other years.
5275 Add a copy of the correspondence that's the basis for claims about
5276 DST in the Navajo Nation.
5279 Release 2003e - 2003-12-15 09:36:47 -0500
5281 changes by Arthur David Olson (primarily code changes)
5283 changes by Paul Eggert (primarily data changes)
5285 minor changes to "Makefile" and "northamerica" (in the latter case,
5286 optimization of the "Toronto" rules)
5289 Release 2003d - 2003-10-06 09:34:44 -0400
5291 changes by Paul Eggert
5294 Release 2003c - 2003-09-16 10:47:05 -0400
5296 Fix bad returns in zic.c's inleap function.
5297 Thanks to Bradley White for catching the problem!
5300 Release 2003b - 2003-09-16 07:13:44 -0400
5302 Add a "--version" option (and documentation) to the zic and zdump commands.
5304 changes to overflow/underflow checking in zic
5306 a localtime typo fix.
5308 Update the leapseconds and tz-art.htm files.
5311 Release 2003a - 2003-03-24 09:30:54 -0500
5313 changes by Paul Eggert
5315 a few additions and modifications to the tz-art.htm file
5318 Release 2002d - 2002-10-15 13:12:42 -0400
5320 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
5322 There's also a new time zone quote in "tz-art.htm".
5325 Release 2002c - 2002-04-04 11:55:20 -0500
5327 changes by Paul Eggert
5329 Change zic.c to avoid creating symlinks to files that don't exist.
5332 Release 2002b - 2002-01-28 12:56:03 -0500
5334 [These change notes are for Release 2002a, which was corrupted.
5335 2002b was a corrected version of 2002a.]
5337 changes by Paul Eggert
5339 Update the "leapseconds" file to note that there'll be no leap
5340 second at the end of June, 2002.
5342 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
5344 Change to "difftime.c" to avoid sizeof problems.
5347 Release 2001d - 2001-10-09 13:31:32 -0400
5349 changes by Paul Eggert
5352 Release 2001c - 2001-06-05 13:59:55 -0400
5354 changes by Paul Eggert and Andrew Brown
5357 Release 2001b - 2001-04-05 16:44:38 -0400
5359 changes by Paul Eggert (modulo jnorgard's typo fix)
5361 tz-art.htm has been HTMLified.
5364 Release 2001a - 2001-03-13 12:57:44 -0500
5366 changes by Paul Eggert
5368 An addition to the "leapseconds" file: comments with the text of the
5369 latest IERS leap second notice.
5371 Trailing white space has been removed from data file lines, and
5372 repeated spaces in "Rule Jordan" lines in the "asia" file have been
5376 Release 2000h - 2000-12-14 15:33:38 -0500
5378 changes by Paul Eggert
5380 one typo fix in the "art" file
5382 With providence, this is the last update of the millennium.
5385 Release 2000g - 2000-10-10 11:35:22 -0400
5387 changes by Paul Eggert
5389 correction of John Mackin's name submitted by Robert Elz
5391 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
5392 Emmy Awards broadcast.
5395 Release 2000f - 2000-08-10 09:31:58 -0400
5397 changes by Paul Eggert
5399 Added information in "tz-art.htm" on a Seinfeld reference to DST.
5401 Error checking and messages in the "yearistype" script have been
5405 Release 2000e - 2000-07-31 09:27:54 -0400
5407 data changes by Paul Eggert
5409 a change to the default value of the defined constant HAVE_STRERROR
5411 the addition of a Dave Barry quote on DST to the tz-arts file
5414 Release 2000d - 2000-04-20 15:43:04 -0400
5416 changes to the documentation and code of strftime for C99 conformance
5418 a bug fix for date.c
5420 These are based on (though modified from) changes by Paul Eggert.
5423 Release 2000c - 2000-03-04 10:31:43 -0500
5425 changes by Paul Eggert
5428 Release 2000b - 2000-02-21 12:16:29 -0500
5430 changes by Paul Eggert and Joseph Myers
5432 modest tweaks to the tz-art.htm and tz-link.htm files
5435 Release 2000a - 2000-01-18 09:21:26 -0500
5437 changes by Paul Eggert
5439 The two hypertext documents have also been renamed.
5442 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
5444 Paul Eggert's changes
5446 additions to the "zic" manual page and the "Arts.htm" file
5449 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
5454 Release data1999h - 1999-10-07 03:50:29 -0400
5456 changes by Paul Eggert to "europe" (most importantly, fixing
5457 Lithuania and Estonia)
5460 Release 1999g - 1999-09-28 11:06:18 -0400
5462 data changes by Paul Eggert (most importantly, the change for
5463 Lebanon that buys correctness for this coming Sunday)
5465 The "code" file contains changes to "Makefile" and "checktab.awk" to
5466 allow better checking of time zone files before they are published.
5469 Release 1999f - 1999-09-23 09:48:14 -0400
5471 changes by Arthur David Olson and Paul Eggert
5474 Release 1999e - 1999-08-17 15:20:54 -0400
5476 changes circulated by Paul Eggert, although the change to handling
5477 of DST-specifying timezone names has been commented out for now
5478 (search for "XXX" in "localtime.c" for details). These files also
5479 do not make any changes to the start of DST in Brazil.
5481 In addition to Paul's changes, there are updates to "Arts.htm" and
5485 Release 1999d - 1999-03-30 11:31:07 -0500
5487 changes by Paul Eggert
5489 The Makefile's "make public" rule has also been changed to do a test
5490 compile of each individual time zone data file (which should help
5491 avoid problems such as the one we had with Nicosia).
5494 Release 1999c - 1999-03-25 09:47:47 -0500
5496 changes by Paul Eggert, most importantly the change for Chile.
5499 Release 1999b - 1999-02-01 17:51:44 -0500
5501 changes by Paul Eggert
5503 code changes (suggested by Mani Varadarajan, mani at be.com) for
5504 correct handling of symbolic links when building using a relative directory
5506 code changes to generate correct messages for failed links
5508 updates to the URLs in Arts.htm
5511 Release 1999a - 1999-01-19 16:20:29 -0500
5513 error message internationalizations and corrections in zic.c and
5514 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5518 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5520 changes for Brazil, Chile, and Germany
5522 support for use of "24:00" in the input files for the time zone compiler
5525 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5527 changes by Paul Eggert
5529 correction to a define in the "private.h" file
5532 Release data1998g - 1998-08-11 03:28:35 -0000
5533 [tzdata1998g.tar.gz is missing!]
5535 Lithuanian change provided by mgedmin at pub.osf.it
5537 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5538 "backward") to ensure that the GMT file is created even where folks
5539 don't want the "backward" links (as suggested by Paul Eggert).
5542 Release data1998f - 1998-07-20 13:50:00 -0000
5543 [tzdata1998f.tar.gz is missing!]
5545 Update the "leapseconds" file to include the newly announced
5546 insertion at the end of 1998.
5549 Release code1998f - 1998-06-01 10:18:31 -0400
5551 addition to localtime.c by Guy Harris
5554 Release 1998e - 1998-05-28 09:56:26 -0400
5556 The Makefile is changed to produce zoneinfo-posix rather than
5557 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5560 data changes by Paul Eggert
5562 changes from Guy Harris to provide asctime_r and ctime_r
5564 A usno1998 file (substantially identical to usno1997) has been added.
5567 Release 1998d - 1998-05-14 11:58:34 -0400
5569 changes to comments (in particular, elimination of references to CIA maps).
5570 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5571 where changes occur.
5574 Release 1998c - 1998-02-28 12:32:26 -0500
5576 changes by Paul Eggert (save the "French correction," on which I'll
5577 wait for the dust to settle)
5581 changes and additions to Arts.htm
5584 Release 1998b - 1998-01-17 14:31:51 -0500
5586 URL cleanups and additions
5589 Release 1998a - 1998-01-13 12:37:35 -0500
5591 changes by Paul Eggert
5594 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5596 changes by Paul Eggert, with minor modifications from Arthur David
5597 Olson to make the files more browser friendly
5600 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5602 minor changes to put "TZif" at the start of each timezone information file
5604 a rule has also been added to the Makefile so you can
5606 to just recompile the zone information files (rather than doing a
5607 full "make install" with its other effects).
5610 Release data1997i - 1997-10-07 08:45:38 -0400
5612 changes to Africa by Paul Eggert
5615 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5617 corrections for Uruguay (and other locations)
5619 Arthur David Olson's simple-minded fix allowing mktime to both
5620 correctly handle leap seconds and correctly handle tm_sec values
5621 upon which arithmetic has been performed.
5624 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5626 Paul Eggert's updates
5628 a small change to a function prototype;
5630 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5631 include information on Around the World in Eighty Days.
5634 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5636 fixes to zic's error handling
5638 changes inspired by the item circulated on Slovenia
5640 The description of Web resources has been HTMLified for browsing
5643 A new piece of tz-related music has been added to the "Music" file.
5646 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5648 Paul Eggert's latest suggestions
5651 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5653 changes to "zic.c" to correct performance of the "-s" option
5655 a new file "usno1997"
5658 Release data1997c - 1997-03-04 09:58:18 -0500
5663 Release 1997b - 1997-02-27 18:34:19 -0500
5665 The data file incorporates the 1997 leap second.
5667 The code file incorporates Arthur David Olson's take on the
5668 zic/multiprocessor/directory-creation situation.
5671 Release 1997a - 1997-01-21 09:11:10 -0500
5673 Paul Eggert's Antarctica (and other changes)
5675 Arthur David Olson finessed the "getopt" issue by checking against
5676 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5677 is returned while SunOS 5.5's manual says EOF is returned).
5680 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5682 Paul Eggert's latest changes
5685 Release code1996n - 1996-12-16 09:42:02 -0500
5687 link snapping fix from Bruce Evans (via Garrett Wollman)
5690 Release data1996m - 1996-11-24 02:37:34 -0000
5691 [tzdata1996m.tar.gz is missing!]
5693 Paul Eggert's batch of changes
5696 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5698 No functional changes here; the files have simply been changed to
5699 make more use of ISO style dates in comments. The names of the above
5700 files now include the year in full.
5703 Release code96l - 1996-09-08 17:12:20 -0400
5705 tzcode96k was missing a couple of pieces.
5708 Release 96k - 1996-09-08 16:06:22 -0400
5710 the latest round of changes from Paul Eggert
5712 the recent Year 2000 material
5715 Release code96j - 1996-07-30 13:18:53 -0400
5717 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5720 Release code96i - 1996-07-27 20:11:35 -0400
5722 Paul's suggested patch for strftime %V week numbers
5725 Release data96i - 1996-07-01 18:13:04 -0400
5727 "northamerica" and "europe" changes by Paul Eggert
5730 Release code96h - 1996-06-05 08:02:21 -0400
5732 fix for handling transitions specified in Universal Time
5734 Some "public domain" notices have also been added.
5737 Release code96g - 1996-05-16 14:00:26 -0400
5739 fix for the simultaneous-DST-and-zone-change challenge
5742 Release data96h - 1996-05-09 17:40:51 -0400
5744 changes by Paul Eggert
5747 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5748 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5750 The changes get us some of the way to fixing the problems noted in Paul
5751 Eggert's letter yesterday (in addition to a few others). The approach
5752 has been to make zic a bit smarter about figuring out what time zone
5753 abbreviations apply just after the time specified in the "UNTIL" part
5754 of a zone line. Putting the smarts in zic means avoiding having
5755 transition times show up in both "Zone" lines and "Rule" lines, which
5756 in turn avoids multiple transition time entries in time zone files.
5757 (This also makes the zic input files such as "europe" a bit shorter and
5758 should ease maintenance.)
5761 Release data96f - 1996-04-19 19:20:03 -0000
5762 [tzdata96f.tar.gz is missing!]
5764 The only changes are to the "northamerica" file; the time zone
5765 abbreviation for Denver is corrected to MST (and MDT), and the
5766 comments for Mexico have been updated.
5769 Release data96e - 1996-03-19 17:37:26 -0500
5771 Proposals by Paul Eggert, in particular the Portugal change that
5772 comes into play at the end of this month.
5775 Release data96d - 1996-03-18 20:49:39 -0500
5780 Release code96e - 1996-02-29 15:43:27 -0000
5781 [tzcode96e.tar.gz is missing!]
5783 internationalization changes and the fix to the documentation for strftime
5786 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5788 The "code" file simply updates Bob Kridle's electronic address.
5790 The "data" file updates rules for Mexico.
5793 Release data96b - 1996-01-27 15:44:42 -0500
5798 Release code96c - 1996-01-16 16:58:15 -0500
5800 leap-year streamlining and binary-search changes
5805 Release code96b - 1996-01-10 20:42:39 -0500
5807 fixes and enhancements from Paul Eggert, including code that
5808 emulates the behavior of recent versions of the SunOS "date"
5812 Release 96a - 1996-01-06 09:08:24 -0500
5816 fixes to strftime.c for correct ISO 8601 week number generation,
5817 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5818 numbers (which are not necessarily the same as calendar year numbers)
5821 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5823 The latest revisions from Paul Eggert are included, the usno1995
5824 file has been updated, and a new file ("WWW") covering useful URLs
5828 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5830 A simplification of a macro definition, a change to data for Sudan,
5831 and (for last minute shoppers) notes in the "Music" file on the CD
5835 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5837 (slightly reformatted) 8-bit-clean proposed patch
5839 minor patch: US/Eastern -> America/New_York
5841 snapshot of the USNO's latest data ("usno1995")
5843 some other minor cleanups
5846 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5847 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5851 support for 64-bit time_t's
5853 optimization in localtime.c
5856 Release code95e - 1995-10-13 13:23:57 -0400
5858 the mktime change to scan from future to past when trying to find time zone
5862 Release data95i - 1995-09-26 10:43:26 -0400
5864 For Canada/Central, guess that the Sun customer's "one week too
5865 early" was just a approximation, and the true error is one month
5866 too early. This is consistent with the rest of Canada.
5869 Release data95h - 1995-09-21 11:26:48 -0400
5871 latest changes from Paul Eggert
5874 Release code95d - 1995-09-14 11:14:45 -0400
5876 the addition of a "Music" file, which documents four recorded
5877 versions of the tune "Save That Time".
5880 Release data95g - 1995-09-01 17:21:36 -0400
5882 "yearistype" correction
5885 Release data95f - 1995-08-28 20:46:56 -0400
5887 Paul Eggert's change to the australasia file
5890 Release data95e - 1995-07-08 18:02:34 -0400
5892 The only change is a leap second at the end of this year.
5893 Thanks to Bradley White for forwarding news on the leap second.
5896 Release data95d - 1995-07-03 13:26:22 -0400
5898 Paul Eggert's changes
5901 Release data95c - 1995-07-02 19:19:28 -0400
5903 changes to "asia", "backward", "europe", and "southamerica"
5904 (read: northamericacentrics need not apply)
5907 Release code95c - 1995-03-13 14:00:46 -0500
5909 one-line fix for sign extension problems in detzcode
5912 Release 95b - 1995-03-04 11:22:38 -0500
5914 Minor changes in both:
5916 The "code" file contains a workaround for the lack of "unistd.h" in
5917 Microsoft C++ version 7.
5919 The "data" file contains a fixed "Link" for America/Shiprock.
5922 Release 94h - 1994-12-10 12:51:14 -0500
5926 * incorporate the changes to "zdump" and "date" to make changes to
5927 the "TZ" environment variable permanent;
5929 * incorporate the table changes by Paul Eggert;
5931 * include (and document) support for universal time specifications in
5932 data files - but do not (yet) include use of this feature in the
5935 Think of this as "TZ Classic" - the software has been set up not to break if
5936 universal time shows up in its input, and data entries have been
5937 left as is so as not to break existing implementations.
5940 Release data94f - 1994-08-20 12:56:09 -0400
5942 (with thanks!) the latest data updates from Paul Eggert
5945 Release data94e - 1994-06-04 13:13:53 -0400
5950 Release code94g - 1994-05-05 12:14:07 -0400
5952 fix missing "optind.c" and a reference to it in the Makefile
5955 Release code94f - 1994-05-05 13:00:33 -0000
5956 [tzcode94f.tar.gz is missing!]
5958 changes to avoid overflow in difftime, as well as changes to cope
5959 with the 52/53 challenge in strftime
5962 Release code94e - 1994-03-30 23:32:59 -0500
5964 change for the benefit of PCTS
5967 Release 94d - 1994-02-24 15:42:25 -0500
5969 Avoid clashes with POSIX semantics for zones such as GMT+4.
5971 Some other very minor housekeeping is also present.
5974 Release code94c - 1994-02-10 08:52:40 -0500
5976 Fix bug where mkdirs was broken unless you compile with
5977 -fwritable-strings (which is generally losing to do).
5980 Release 94b - 1994-02-07 10:04:33 -0500
5982 work by Paul Eggert who notes:
5984 I found another book of time zone histories by E W Whitman; it's not
5985 as extensive as Shanks but has a few goodies of its own. I used it
5986 to update the tables. I also fixed some more as a result of
5987 correspondence with Adam David and Peter Ilieve, and move some stray
5988 links from 'europe' to 'backward'. I corrected some scanning errors
5991 As far as the code goes, I fixed zic to allow years in the range
5992 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5993 And I cleaned up the zic documentation a little bit.
5996 Release data94a - 1994-02-03 08:58:54 -0500
5998 It simply incorporates the recently announced leap second into the
6002 Release 93g - 1993-11-22 17:28:27 -0500
6004 Paul Eggert has provided a good deal of historic information (based
6005 on Shanks), and there are some code changes to deal with the buglets
6006 that crawled out in dealing with the new information.
6009 Release 93f - 1993-10-15 12:27:46 -0400
6011 Paul Eggert's changes
6014 Release 93e - 1993-09-05 21:21:44 -0400
6016 This has updated data for Israel, England, and Kwajalein. There's
6017 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
6018 Thanks to Paul Eggert and Peter Ilieve for the changes.
6021 Release 93d - 1993-06-17 23:34:17 -0400
6023 new fix and new data on Israel
6026 Release 93c - 1993-06-06 19:31:55 -0400
6031 Release 93b - 1993-02-02 14:53:58 -0500
6033 updated "leapseconds" file
6036 Release 93 - 1993-01-08 07:01:06 -0500
6038 At kre's suggestion, the package has been split in two - a code piece
6039 (which also includes documentation) that's only of use to folks who
6040 want to recompile things and a data piece useful to anyone who can
6043 The new version has a few changes to the data files, a few
6044 portability changes, and an off-by-one fix (with thanks to
6045 Tom Karzes at deshaw.com for providing a description and a
6049 Release 92c - 1992-11-21 17:35:36 -0000
6050 [tz92c.tar.Z is missing!]
6052 The fallout from the latest round of DST transitions.
6054 There are changes for Portugal, Saskatchewan, and "Pacific-New";
6055 there's also a change to "zic.c" that makes it portable to more systems.
6058 Release 92 - 1992-04-25 18:17:03 -0000
6059 [tz92.tar.Z is missing!]
6061 By popular demand (well, at any rate, following a request by kre at munnari)
6064 The 1989 update of the time zone package featured:
6066 * POSIXization (including interpretation of POSIX-style TZ environment
6067 variables, provided by Guy Harris),
6068 * ANSIfication (including versions of "mktime" and "difftime"),
6069 * SVIDulation (an "altzone" variable)
6070 * MACHination (the "gtime" function)
6071 * corrections to some time zone data (including corrections to the rules
6072 for Great Britain and New Zealand)
6073 * reference data from the United States Naval Observatory for folks who
6074 want to do additional time zones
6075 * and the 1989 data for Saudi Arabia.
6077 (Since this code will be treated as "part of the implementation" in some
6078 places and as "part of the application" in others, there's no good way to
6079 name functions, such as timegm, that are not part of the proposed ANSI C
6080 standard; such functions have kept their old, underscore-free names in this
6083 And the "dysize" function has disappeared; it was present to allow
6084 compilation of the "date" command on old BSD systems, and a version of "date"
6085 is now provided in the package. The "date" command is not created when you
6086 "make all" since it may lack options provided by the version distributed with
6087 your operating system, or may not interact with the system in the same way
6088 the native version does.
6090 Since POSIX frowns on correct leap second handling, the default behavior of
6091 the "zic" command (in the absence of a "-L" option) has been changed to omit
6092 leap second information from its output files.
6098 This file contains copies of the part of each release announcement
6099 that talks about the changes in that release. The text has been
6100 adapted and reformatted for the purposes of this file.
6102 Traditionally a release R consists of a pair of tarball files,
6103 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
6104 code2010a, data2012c) consist of just one or the other tarball, and a
6105 few (e.g., code2012c-data2012d) have tarballs with mixed version
6106 numbers. Recent releases also come in an experimental format
6107 consisting of a single tarball tzdb-R.tar.lz with extra data.
6109 Release timestamps are taken from the release's commit (for newer,
6110 Git-based releases), from the newest file in the tarball (for older
6111 releases, where this info is available) or from the email announcing
6112 the release (if all else fails; these are marked with a time zone
6113 abbreviation of -0000 and an "is missing!" comment).
6115 Earlier versions of the code and data were not announced on the tz
6116 list and are not summarized here.
6118 This file is in the public domain.