1 News for the tz database
3 Release 2023a - 2023-03-22 12:39:33 -0700
6 Egypt now uses DST again, from April through October.
7 This year Morocco springs forward April 23, not April 30.
8 Palestine delays the start of DST this year.
9 Much of Greenland still uses DST from 2024 on.
10 America/Yellowknife now links to America/Edmonton.
11 tzselect can now use current time to help infer timezone.
12 The code now defaults to C99 or later.
13 Fix use of C23 attributes.
15 Changes to future timestamps
17 Starting in 2023, Egypt will observe DST from April's last Friday
18 through October's last Thursday. (Thanks to Ahmad ElDardiry.)
19 Assume the transition times are 00:00 and 24:00, respectively.
21 In 2023 Morocco's spring-forward transition after Ramadan
22 will occur April 23, not April 30. (Thanks to Milamber.)
23 Adjust predictions for future years accordingly. This affects
24 predictions for 2023, 2031, 2038, and later years.
26 This year Palestine will delay its spring forward from
27 March 25 to April 29 due to Ramadan. (Thanks to Heba Hamad.)
28 Make guesses for future Ramadans too.
30 Much of Greenland, represented by America/Nuuk, will continue to
31 observe DST using European Union rules. When combined with
32 Greenland's decision not to change the clocks in fall 2023,
33 America/Nuuk therefore changes from -03/-02 to -02/-01 effective
34 2023-10-29 at 01:00 UTC. (Thanks to Thomas M. Steenholdt.)
35 This change from 2022g doesn't affect timestamps until 2024-03-30,
36 and doesn't affect tm_isdst until 2023-03-25.
38 Changes to past timestamps
40 America/Yellowknife has changed from a Zone to a backward
41 compatibility Link, as it no longer differs from America/Edmonton
42 since 1970. (Thanks to Almaz Mingaleev.) This affects some
43 pre-1948 timestamps. The old data are now in 'backzone'.
45 Changes to past time zone abbreviations
47 When observing Moscow time, Europe/Kirov and Europe/Volgograd now
48 use the abbreviations MSK/MSD instead of numeric abbreviations,
49 for consistency with other timezones observing Moscow time.
53 You can now tell tzselect local time, to simplify later choices.
54 Select the 'time' option in its first prompt.
56 You can now compile with -DTZNAME_MAXIMUM=N to limit time zone
57 abbreviations to N bytes (default 255). The reference runtime
58 library now rejects POSIX-style TZ strings that contain longer
59 abbreviations, treating them as UTC. Previously the limit was
60 platform dependent and abbreviations were silently truncated to
61 16 bytes even when the limit was greater than 16.
63 The code by default is now designed for C99 or later. To build in
64 a C89 environment, compile with -DPORT_TO_C89. To support C89
65 callers of the tzcode library, compile with -DSUPPORT_C89. The
66 two new macros are transitional aids planned to be removed in a
67 future version, when C99 or later will be required.
69 The code now builds again on pre-C99 platforms, if you compile
70 with -DPORT_TO_C89. This fixes a bug introduced in 2022f.
72 On C23-compatible platforms tzcode no longer uses syntax like
73 'static [[noreturn]] void usage(void);'. Instead, it uses
74 '[[noreturn]] static void usage(void);' as strict C23 requires.
75 (Problem reported by Houge Langley.)
77 The code's functions now constrain their arguments with the C
78 'restrict' keyword consistently with their documentation.
79 This may allow future optimizations.
81 zdump again builds standalone with ckdadd and without setenv,
82 fixing a bug introduced in 2022g. (Problem reported by panic.)
84 leapseconds.awk can now process a leap seconds file that never
85 expires; this might be useful if leap seconds are discontinued.
89 tz-link.html has a new section "Coordinating with governments and
90 distributors". (Thanks to Neil Fuller for some of the text.)
92 To improve tzselect diagnostics, zone1970.tab's comments column is
93 now limited to countries that have multiple timezones.
95 Note that leap seconds are planned to be discontinued by 2035.
98 Release 2022g - 2022-11-29 08:58:31 -0800
101 The northern edge of Chihuahua changes to US timekeeping.
102 Much of Greenland stops changing clocks after March 2023.
103 Fix some pre-1996 timestamps in northern Canada.
104 C89 is now deprecated; please use C99 or later.
105 Portability fixes for AIX, libintl, MS-Windows, musl, z/OS
106 In C code, use more C23 features if available.
107 C23 timegm now supported by default
108 Fixes for unlikely integer overflows
110 Changes to future timestamps
112 In the Mexican state of Chihuahua, the border strip near the US
113 will change to agree with nearby US locations on 2022-11-30.
114 The strip's western part, represented by Ciudad Juárez, switches
115 from -06 all year to -07/-06 with US DST rules, like El Paso, TX.
116 The eastern part, represented by Ojinaga, will observe US DST next
117 year, like Presidio, TX. (Thanks to Heitor David Pinto.)
118 A new Zone America/Ciudad_Juarez splits from America/Ojinaga.
120 Much of Greenland, represented by America/Nuuk, stops observing
121 winter time after March 2023, so its daylight saving time becomes
122 standard time. (Thanks to Jonas Nyrup and Jürgen Appel.)
124 Changes to past timestamps
126 Changes for pre-1996 northern Canada (thanks to Chris Walton):
128 Merge America/Iqaluit and America/Pangnirtung into the former,
129 with a backward compatibility link for the latter name.
130 There is no good evidence the two locations differ since 1970.
131 This change affects pre-1996 America/Pangnirtung timestamps.
133 Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and
134 Yellowknife did not observe DST in 1965, and did observe DST
135 from 1972 through 1979.
137 Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28.
139 Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00.
140 (Thanks to Alois Treindl.)
142 Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time),
143 not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.)
147 Although tzcode still works with C89, bugs found in recent routine
148 maintenance indicate that bitrot has set in and that in practice
149 C89 is no longer used to build tzcode. As it is a maintenance
150 burden, support for C89 is planned to be removed soon. Instead,
151 please use compilers compatible with C99, C11, C17, or C23.
153 timegm, which tzcode implemented in 1989, will finally be
154 standardized 34 years later as part of C23, so timegm is now
155 supported even if STD_INSPIRED is not defined.
157 Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone.
158 (Problem reported by Đoàn Trần Công Danh.)
160 Fix bug in zic on hosts where malloc(0) yields NULL on success.
161 (Problem reported by Tim McBrayer for AIX 6.1.)
163 Fix zic configuration to avoid linkage failures on some platforms.
164 (Problems reported by Gilmore Davidson and Igor Ivanov.)
166 Work around MS-Windows nmake incompatibility with POSIX.
167 (Problem reported by Manuela Friedrich.)
169 Port mktime and strftime to debugging platforms where accessing
170 uninitialized data has undefined behavior (strftime problem
171 reported by Robert Elz).
173 Check more carefully for unlikely integer overflows, preferring
174 C23 <stdckdint.h> to overflow checking by hand, as the latter has
177 Changes to build procedure
179 New Makefile rule check_mild that skips checking whether Link
180 lines are in the file 'backward'. (Inspired by a suggestion from
184 Release 2022f - 2022-10-28 18:04:57 -0700
187 Mexico will no longer observe DST except near the US border.
188 Chihuahua moves to year-round -06 on 2022-10-30.
189 Fiji no longer observes DST.
190 Move links to 'backward'.
191 In vanguard form, GMT is now a Zone and Etc/GMT a link.
192 zic now supports links to links, and vanguard form uses this.
193 Simplify four Ontario zones.
194 Fix a Y2438 bug when reading TZif data.
195 Enable 64-bit time_t on 32-bit glibc platforms.
196 Omit large-file support when no longer needed.
197 In C code, use some C23 features if available.
198 Remove no-longer-needed workaround for Qt bug 53071.
200 Changes to future timestamps
202 Mexico will no longer observe DST after 2022, except for areas
203 near the US border that continue to observe US DST rules.
204 On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
205 from -07 (-06 with DST) to year-round -06, thus not changing
206 its clocks that day. The new law states that Chihuahua
207 near the US border no longer observes US DST.
208 (Thanks to gera for the heads-up about Chihuahua.)
210 Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.)
211 For now, assume DST is suspended indefinitely.
215 Move links to 'backward' to ease and simplify link maintenance.
216 This affects generated data only if you use 'make BACKWARD='.
218 GMT is now a Zone and Etc/GMT a link instead of vice versa,
219 as GMT is needed for leap second support whereas Etc/GMT is not.
220 However, this change exposes a bug in TZUpdater 2.3.2 so it is
221 present only in vanguard form for now.
223 Vanguard form now uses links to links, as zic now supports this.
225 Changes to past timestamps
227 Simplify four Ontario zones, as most of the post-1970 differences
228 seem to have been imaginary. (Problem reported by Chris Walton.)
229 Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay
230 to 'backzone'; backward-compatibility links still work, albeit
231 with some different timestamps before November 2005.
235 zic now supports links to links regardless of input line order.
236 For example, if Australia/Sydney is a Zone, the lines
237 Link Australia/Canberra Australia/ACT
238 Link Australia/Sydney Australia/Canberra
239 now work correctly, even though the shell commands
240 ln Australia/Canberra Australia/ACT
241 ln Australia/Sydney Australia/Canberra
242 would fail because the first command attempts to use a link
243 Australia/Canberra that does not exist until after the second
244 command is executed. Previously, zic had unspecified behavior if
245 a Link line's target was another link, and zic often misbehaved if
246 a Link line's target was a later Link line.
248 Fix line number in zic's diagnostic for a link to a link.
250 Fix a bug that caused localtime to mishandle timestamps starting
251 in the year 2438 when reading data generated by 'zic -b fat' when
252 distant-future DST transitions occur at times given in standard
253 time or in UT, not the usual case of local time. This occurs when
254 the corresponding .zi Rule lines specify DST transitions with TO
255 columns of 'max' and AT columns that end in 's' or 'u'. The
256 number 2438 comes from the 32-bit limit in the year 2038, plus the
257 400-year Gregorian cycle. (Problem reported by Bradley White.)
259 On glibc 2.34 and later, which optionally supports 64-bit time_t
260 on platforms like x86 where time_t was traditionally 32 bits,
261 default time_t to 64 instead of 32 bits. This lets functions like
262 localtime support timestamps after the year 2038, and fixes
263 year-2038 problems in zic when accessing files dated after 2038.
264 To continue to limit time_t to 32 bits on these platforms, use
265 "make CFLAGS='-D_TIME_BITS=32'".
267 In C code, do not enable large-file support on platforms like AIX
268 and macOS that no longer need it now that tzcode does not use
269 off_t or related functions like 'stat'. Large-file support is
270 still enabled by default on GNU/Linux, as it is needed for 64-bit
273 In C code, prefer C23 keywords to pre-C23 macros for alignof,
274 bool, false, and true. Also, use the following C23 features if
275 available: __has_include, unreachable.
277 zic no longer works around Qt bug 53071, as the relevant Qt
278 releases have been out of support since 2019. This change affects
279 only fat TZif files, as thin files never had the workaround.
281 zdump no longer modifies the environ vector when compiled on
282 platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
283 This avoid undefined behavior on POSIX platforms.
286 Release 2022e - 2022-10-11 11:13:02 -0700
289 Jordan and Syria switch from +02/+03 with DST to year-round +03.
291 Changes to future timestamps
293 Jordan and Syria are abandoning the DST regime and are changing to
294 permanent +03, so they will not fall back from +03 to +02 on
295 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.)
297 Changes to past timestamps
299 On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00.
301 Changes to past time zone abbreviations and DST flags
303 The temporary advancement of clocks in central Mexico in summer
304 1931 is now treated as daylight saving time, instead of as two
305 changes to standard time.
308 Release 2022d - 2022-09-23 12:02:57 -0700
311 Palestine transitions are now Saturdays at 02:00.
312 Simplify three Ukraine zones into one.
314 Changes to future timestamps
316 Palestine now springs forward and falls back at 02:00 on the
317 first Saturday on or after March 24 and October 24, respectively.
318 This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00.
319 (Thanks to Heba Hamad.)
321 Changes to past timestamps
323 Simplify three Ukraine zones to one, since the post-1970
324 differences seem to have been imaginary. Move Europe/Uzhgorod and
325 Europe/Zaporozhye to 'backzone'; backward-compatibility links
326 still work, albeit with different timestamps before October 1991.
329 Release 2022c - 2022-08-15 17:47:18 -0700
332 Work around awk bug in FreeBSD, macOS, etc.
333 Improve tzselect on intercontinental Zones.
337 Work around a bug in onetrueawk that broke commands like
338 'make traditional_tarballs' on FreeBSD, macOS, etc.
339 (Problem reported by Deborah Goldsmith.)
341 Add code to tzselect that uses experimental structured comments in
342 zone1970.tab to clarify whether Zones like Africa/Abidjan and
343 Europe/Istanbul cross continent or ocean boundaries.
344 (Inspired by a problem reported by Peter Krefting.)
346 Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
347 directory /a/b already exists.
349 Remove zoneinfo2tdf.pl, as it was unused and triggered false
350 malware alarms on some email servers.
353 Release 2022b - 2022-08-10 15:38:32 -0700
356 Chile's DST is delayed by a week in September 2022.
357 Iran no longer observes DST after 2022.
358 Rename Europe/Kiev to Europe/Kyiv.
360 Vanguard form now uses %z.
361 Finish moving duplicate-since-1970 zones to 'backzone'.
362 New build option PACKRATLIST
363 New tailored_tarballs target, replacing rearguard_tarballs
365 Changes to future timestamps
367 Chile's 2022 DST start is delayed from September 4 to September 11.
368 (Thanks to Juan Correa.)
370 Iran plans to stop observing DST permanently, after it falls back
371 on 2022-09-21. (Thanks to Ali Mirjamali.)
373 Changes to past timestamps
375 Finish moving to 'backzone' the location-based zones whose
376 timestamps since 1970 are duplicates; adjust links accordingly.
377 This change ordinarily affects only pre-1970 timestamps, and with
378 the new PACKRATLIST option it does not affect any timestamps.
379 In this round the affected zones are Antarctica/Vostok,
380 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
381 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
382 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
383 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
384 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
385 Pacific/Wake and Pacific/Wallis, and the affected links are
386 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
387 Pacific/Truk, and Pacific/Yap.
389 From fall 1994 through fall 1995, Shanks wrote that Crimea's
390 DST transitions were at 02:00 standard time, not at 00:00.
391 (Thanks to Michael Deckers.)
393 Iran adopted standard time in 1935, not 1946. In 1977 it observed
394 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
395 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
396 transition was on 05-27, not 03-21.
397 (Thanks to Roozbeh Pournader and Francis Santoni.)
399 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
400 considered DST, not standard time. Santiago and environs had moved
401 their clocks back to rejoin the rest of mainland Chile; put this
402 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
404 Some old, small clock transitions have been removed, as people at
405 the time did not change their clocks. This affects Asia/Hong_Kong
406 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
410 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
411 English now. Spelling of other names in Ukraine has not yet
412 demonstrably changed in common English practice so for now these
413 names retain old spellings, as in other countries (e.g.,
414 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
418 zic has a new option '-R @N' to output explicit transitions < N.
419 (Need suggested by Almaz Mingaleev.)
421 'zic -r @N' no longer outputs bad data when N < first transition.
422 (Problem introduced in 2021d and reported by Peter Krefting.)
424 zic now checks its input for NUL bytes and unterminated lines, and
425 now supports input line lengths up to 2048 (not 512) bytes.
427 gmtime and related code now use the abbreviation "UTC" not "GMT".
428 POSIX is being revised to require this.
430 When tzset and related functions set vestigial static variables
431 like tzname, they now prefer specified timestamps to unspecified ones.
432 (Problem reported by Almaz Mingaleev.)
434 zic no longer complains "can't determine time zone abbreviation to
435 use just after until time" when a transition to a new standard
436 time occurs simultaneously with the first DST fallback transition.
438 Changes to build procedure
440 Source data in vanguard form now uses the %z notation, introduced
441 in release 2015f. For example, for America/Sao_Paulo vanguard
442 form contains the zone continuation line "-3:00 Brazil %z", which
443 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
444 used in main and rearguard forms. The plan is for the main form
445 to use %z eventually; in the meantime maintainers of zi parsers
446 are encouraged to test the parsers on vanguard.zi.
448 The Makefile has a new PACKRATLIST option to select a subset of
449 'backzone'. For example, 'make PACKRATDATA=backzone
450 PACKRATLIST=zone.tab' now generates TZif files identical to those
451 of the global-tz project.
453 The Makefile has a new tailored_tarballs target for generating
454 special-purpose tarballs. It generalizes and replaces the
455 rearguard_tarballs target and related targets and macros, which
458 'make install' now defaults LOCALTIME to Factory not GMT,
459 which means the default abbreviation is now "-00" not "GMT".
461 Remove the posix_packrat target, marked obsolescent in 2016a.
464 Release 2022a - 2022-03-15 23:02:01 -0700
467 Palestine will spring forward on 2022-03-27, not -03-26.
468 zdump -v now outputs better failure indications.
469 Bug fixes for code that reads corrupted TZif data.
471 Changes to future timestamps
473 Palestine will spring forward on 2022-03-27, not 2022-03-26.
474 (Thanks to Heba Hamad.) Predict future transitions for first
475 Sunday >= March 25. Additionally, predict fallbacks to be the first
476 Friday on or after October 23, not October's last Friday, to be more
477 consistent with recent practice. The first differing fallback
478 prediction is on 2025-10-24, not 2025-10-31.
480 Changes to past timestamps
482 From 1992 through spring 1996, Ukraine's DST transitions were at
483 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
485 Chile's Santiago Mean Time and its LMT precursor have been adjusted
486 eastward by 1 second to align with past and present law.
488 Changes to commentary
490 Add several references for Chile's 1946/1947 transitions, some of
491 which only affected portions of the country.
495 Fix bug when mktime gets confused by truncated TZif files with
496 unspecified local time. (Problem reported by Almaz Mingaleev.)
498 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
499 (Problem reported by Christos Zoulas.)
501 When reading a version 2 or later TZif file, the TZif reader now
502 validates the version 1 header and data block only enough to skip
503 over them, as recommended by RFC 8536 section 4. Also, the TZif
504 reader no longer mistakenly attempts to parse a version 1 TZIf
505 file header as a TZ string.
507 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
508 when local time and UT cannot be determined for a timestamp.
510 Changes to build procedure
512 Distribution tarballs now use standard POSIX.1-1988 ustar format
513 instead of GNU format. Although the formats are almost identical
514 for these tarballs, ustar headers' magic fields contain "ustar"
515 instead of "ustar ", and their version fields contain "00" instead
516 of " ". The two formats are planned to diverge more significantly
517 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
518 format becomes obsolete and the tarballs switch to pax format, an
519 extension of ustar. For details about these formats, please see
520 "pax - portable archive interchange", IEEE Std 1003.1-2017,
521 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
524 Release 2021e - 2021-10-21 18:41:00 -0700
526 Changes to future timestamps
528 Palestine will fall back 10-29 (not 10-30) at 01:00.
529 (Thanks to P Chan and Heba Hemad.)
532 Release 2021d - 2021-10-15 13:48:18 -0700
535 Fiji suspends DST for the 2021/2022 season.
536 'zic -r' marks unspecified timestamps with "-00".
538 Changes to future timestamps
540 Fiji will suspend observance of DST for the 2021/2022 season.
541 Assume for now that it will return next year. (Thanks to Jashneel
546 'zic -r' now uses "-00" time zone abbreviations for intervals
547 with UT offsets that are unspecified due to -r truncation.
548 This implements a change in draft Internet RFC 8536bis.
551 Release 2021c - 2021-10-01 14:21:49 -0700
554 Revert most 2021b changes to 'backward'.
555 Fix 'zic -b fat' bug in pre-1970 32-bit data.
556 Fix two Link line typos.
557 Distribute SECURITY file.
559 This release is intended as a bugfix release, to fix compatibility
560 problems and typos reported since 2021b was released.
562 Changes to Link directives
564 Revert almost all of 2021b's changes to the 'backward' file,
565 by moving Link directives back to where they were in 2021a.
566 Although 'zic' doesn't care which source file contains a Link
567 directive, some downstream uses ran into trouble with the move.
568 (Problem reported by Stephen Colebourne for Joda-Time.)
570 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
571 (problem reported by Chris Walton).
573 Fix 'backzone' typo that linked America/Virgin to the wrong
574 location (problem reported by Michael Deckers).
578 Fix a bug in 'zic -b fat' that caused old timestamps to be
579 mishandled in 32-bit-only readers (problem reported by Daniel
582 Changes to documentation
584 Distribute the SECURITY file (problem reported by Andreas Radke).
587 Release 2021b - 2021-09-24 16:23:00 -0700
590 Jordan now starts DST on February's last Thursday.
591 Samoa no longer observes DST.
592 Merge more location-based Zones whose timestamps agree since 1970.
593 Move some backward-compatibility links to 'backward'.
594 Rename Pacific/Enderbury to Pacific/Kanton.
595 Correct many pre-1993 transitions in Malawi, Portugal, etc.
596 zic now creates each output file or link atomically.
597 zic -L no longer omits the POSIX TZ string in its output.
598 zic fixes for truncation and leap second table expiration.
599 zic now follows POSIX for TZ strings using all-year DST.
600 Fix some localtime crashes and bugs in obscure cases.
601 zdump -v now outputs more-useful boundary cases.
602 tzfile.5 better matches a draft successor to RFC 8536.
605 This release is prompted by recent announcements by Jordan and Samoa.
606 It incorporates many other changes that had accumulated since 2021a.
607 However, it omits most proposed changes that merged all Zones
608 agreeing since 1970, as concerns were raised about doing too many of
609 these changes at once. It does keeps some of these changes in the
610 interest of making tzdb more equitable one step at a time; see
611 "Merge more location-based Zones" below.
613 Changes to future timestamps
615 Jordan now starts DST on February's last Thursday.
616 (Thanks to Steffen Thorsen.)
618 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
622 Rename Pacific/Enderbury to Pacific/Kanton. When we added
623 Enderbury in 1993, we did not know that it is uninhabited and that
624 Kanton (population two dozen) is the only inhabited location in
625 that timezone. The old name is now a backward-compatibility link.
627 Changes to past timestamps
629 Correct many pre-1993 transitions, fixing entries originally
630 derived from Shanks, Whitman, and Mundell. The fixes include:
631 - Barbados: standard time was introduced in 1911, not 1932; and
632 DST was observed in 1942-1944
633 - Cook Islands: In 1899 they switched from east to west of GMT,
634 celebrating Christmas for two days. They (and Niue) switched
635 to standard time in 1952, not 1901.
636 - Guyana: corrected LMT for Georgetown; the introduction of
637 standard time in 1911, not 1915; and corrections to 1975 and
639 - Kanton: uninhabited before 1937-08-31
640 - Niue: only observed -11:20 from 1952 through 1964, then went to
641 -11 instead of -11:30
642 - Portugal: DST was observed in 1950
643 - Tonga: corrected LMT; the introduction of standard time in 1945,
644 not 1901; and corrections to the transition from +12:20 to +13
646 Additional fixes to entries in the 'backzone' file include:
647 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
648 - The Gambia: 1933 and 1942 transitions
649 - Malawi: several 1911 through 1925 transitions
650 - Sierra Leone: several 1913 through 1941 transitions, and DST
651 was NOT observed in 1957 through 1962
652 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
655 Merge more location-based Zones whose timestamps agree since 1970,
656 as pre-1970 timestamps are out of scope. This is part of a
657 process that has been ongoing since 2013. This does not affect
658 post-1970 timestamps, and timezone historians who build with 'make
659 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
660 When merging, keep the most-populous location's data, and move
661 data for other locations to 'backzone' with a backward
662 link in 'backward'. For example, move America/Creston data to
663 'backzone' with a link in 'backward' from America/Phoenix because
664 the two timezones' timestamps agree since 1970; this change
665 affects some pre-1968 timestamps in America/Creston because
666 Creston and Phoenix disagreed before 1968. The affected Zones
667 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
668 America/Creston, America/Curacao, America/Nassau,
669 America/Port_of_Spain, Antarctica/DumontDUrville, and
672 Changes to maintenance procedure
674 The new file SECURITY covers how to report security-related bugs.
676 Several backward-compatibility links have been moved to the
677 'backward' file. These links, which range from Africa/Addis_Ababa
678 to Pacific/Saipan, are only for compatibility with now-obsolete
679 guidelines suggesting an entry for every ISO 3166 code.
680 The intercontinental convenience links Asia/Istanbul and
681 Europe/Nicosia have also been moved to 'backward'.
685 zic now creates each output file or link atomically,
686 possibly by creating a temporary file and then renaming it.
687 This avoids races where a TZ setting would temporarily stop
688 working while zic was installing a replacement file or link.
690 zic -L no longer omits the POSIX TZ string in its output.
691 Starting with 2020a, zic -L truncated its output according to the
692 "Expires" directive or "#expires" comment in the leapseconds file.
693 The resulting TZif files omitted daylight saving transitions after
694 the leap second table expired, which led to far less accurate
695 predictions of times after the expiry. Although future timestamps
696 cannot be converted accurately in the presence of leap seconds, it
697 is more accurate to convert near-future timestamps with a few
698 seconds error than with an hour error, so zic -L no longer
699 truncates output in this way.
701 Instead, when zic -L is given the "Expires" directive, it now
702 outputs the expiration by appending a no-change entry to the leap
703 second table. Although this should work well with most TZif
704 readers, it does not conform to Internet RFC 8536 and some pickier
705 clients (including tzdb 2017c through 2021a) reject it, so
706 "Expires" directives are currently disabled by default. To enable
707 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
708 this new feature it is marked with a new TZif version number 4,
709 a format intended to be documented in a successor to RFC 8536.
711 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
712 that omits leap second information for the range LO..B when LO
713 falls between two leap seconds A and B. Instead, it generates a
714 TZif version 4 file that represents the previously missing
717 The TZif reader now allows the leap second table to begin with a
718 correction other than -1 or +1, and to contain adjacent
719 transitions with equal corrections. This supports TZif version 4.
721 The TZif reader now lets leap seconds occur less than 28 days
722 apart. This supports possible future TZif extensions.
724 Fix bug that caused 'localtime' etc. to crash when TZ was
725 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
726 not conform to POSIX but does conform to Internet RFC 8536.
728 Fix another bug that caused 'localtime' etc. to crash when TZ was
729 set to a POSIX-conforming but unusual TZ string like
730 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
732 Fix yet another bug that caused 'localtime' etc. to mishandle slim
733 TZif files containing leap seconds after the last explicit
734 transition in the table, or when handling far-future timestamps
735 in slim TZif files lacking leap seconds.
737 Fix localtime misbehavior involving positive leap seconds.
738 This change affects only behavior for "right" system time,
739 which contains leap seconds, and only if the UT offset is
740 not a multiple of 60 seconds when a positive leap second occurs.
741 (No such timezone exists in tzdb, luckily.) Without the fix,
742 the timestamp was ambiguous during a positive leap second.
743 With the fix, any seconds occurring after a positive leap second
744 and within the same localtime minute are counted through 60, not
745 through 59; their UT offset (tm_gmtoff) is the same as before.
746 Here is how the fix affects timestamps in a timezone with UT
747 offset +01:23:45 (5025 seconds) and with a positive leap second at
748 1972-06-30 23:59:60 UTC (78796800):
750 time_t without the fix with the fix
751 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
752 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
754 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
755 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
757 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
758 civil time changes a few seconds before time_t wraps around, when
759 leap seconds are enabled.
761 Fix bug in zic -r; in some cases, the dummy time type after the
762 last time transition disagreed with the TZ string, contrary to
763 Internet RFC 8563 section 3.3.
765 Fix a bug with 'zic -r @X' when X is a negative leap second that
766 has a nonnegative correction. Without the fix, the output file
767 was truncated so that X appeared to be a positive leap second.
768 Fix a similar, even less likely bug when truncating at a positive
769 leap second that has a nonpositive correction.
771 zic -r now reports an error if given rolling leap seconds, as this
772 usage has never generally worked and is evidently unused.
774 zic now generates a POSIX-conforming TZ string for TZif files
775 where all-year DST is predicted for the indefinite future.
776 For example, for all-year Eastern Daylight Time, zic now generates
777 "XXX3EDT4,0/0,J365/23" where it previously generated
778 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
779 noting the possibility of POSIX conformance.)
781 zic.c no longer requires sys/wait.h (thanks to spazmodius for
782 noting it wasn't needed).
784 When reading slim TZif files, zdump no longer mishandles leap
785 seconds on the rare platforms where time_t counts leap seconds,
786 fixing a bug introduced in 2014g.
788 zdump -v now outputs timestamps at boundaries of what localtime
789 and gmtime can represent, instead of the less useful timestamps
790 one day after the minimum and one day before the maximum.
791 (Thanks to Arthur David Olson for prototype code, and to Manuela
792 Friedrich for debugging help.)
794 zdump's -c and -t options are now consistently inclusive for the
795 lower time bound and exclusive for the upper. Formerly they were
796 inconsistent. (Confusion noted by Martin Burnicki.)
798 Changes to build procedure
800 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
801 non-POSIX hosts where malloc doesn't set errno.
802 (Problem reported by Jan Engelhardt.)
804 Changes to documentation
806 tzfile.5 better matches a draft successor to RFC 8536
807 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
810 Release 2021a - 2021-01-24 10:54:57 -0800
812 Changes to future timestamps
814 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
815 (Thanks to Steffen Thorsen.)
818 Release 2020f - 2020-12-29 00:17:46 -0800
820 Change to build procedure
822 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
823 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
826 Release 2020e - 2020-12-22 15:14:34 -0800
829 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
831 Changes to future timestamps
833 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
834 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
836 Changes to past timestamps
838 Correct many pre-1986 transitions, fixing entries originally
839 derived from Shanks. The fixes include:
840 - Australia: several 1917 through 1971 transitions
841 - The Bahamas: several 1941 through 1945 transitions
842 - Bermuda: several 1917 through 1956 transitions
843 - Belize: several 1942 through 1968 transitions
844 - Ghana: several 1915 through 1956 transitions
845 - Israel and Palestine: several 1940 through 1985 transitions
846 - Kenya and adjacent: several 1908 through 1960 transitions
847 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
848 through 1919 transitions
849 - Seychelles: the introduction of standard time in 1907, not 1906
850 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
853 Because of the Australia change, Australia/Currie (King Island) is
854 no longer needed, as it is identical to Australia/Hobart for all
855 timestamps since 1970 and was therefore created by mistake.
856 Australia/Currie has been moved to the 'backward' file and its
857 corrected data moved to the 'backzone' file.
859 Changes to past time zone abbreviations and DST flags
861 To better match legislation in Turks and Caicos, the 2015 shift to
862 year-round observance of -04 is now modeled as AST throughout before
863 returning to Eastern Time with US DST in 2018, rather than as
864 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
866 Changes to documentation
868 The zic man page now documents zic's coalescing of transitions
869 when a zone falls back just before DST springs forward.
872 Release 2020d - 2020-10-21 11:24:13 -0700
875 Palestine ends DST earlier than predicted, on 2020-10-24.
877 Changes to past and future timestamps
879 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
880 as previously predicted (thanks to Sharef Mustafa.) Its
881 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
882 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
883 its spring 2020 transition was on March 28 at 00:00, not March 27
884 (thanks to Pierre Cashon.) This affects Asia/Gaza and
885 Asia/Hebron. Assume future spring and fall transitions will be on
886 the Saturday preceding the last Sunday of March and October,
890 Release 2020c - 2020-10-16 11:15:53 -0700
893 Fiji starts DST later than usual, on 2020-12-20.
895 Changes to future timestamps
897 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
898 previously predicted. DST will still end on 2021-01-17.
899 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
900 the later-than-usual start date is a one-time departure from the
903 Changes to build procedure
905 Rearguard tarballs now contain an empty file pacificnew.
906 Some older downstream software expects this file to exist.
907 (Problem reported by Mike Cullinan.)
910 Release 2020b - 2020-10-06 18:35:04 -0700
913 Revised predictions for Morocco's changes starting in 2023.
914 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
915 Macquarie Island has stayed in sync with Tasmania since 2011.
916 Casey, Antarctica is at +08 in winter and +11 in summer.
917 zic no longer supports -y, nor the TYPE field of Rules.
919 Changes to future timestamps
921 Morocco's spring-forward after Ramadan is now predicted to occur
922 no sooner than two days after Ramadan, instead of one day.
923 (Thanks to Milamber.) The first altered prediction is for 2023,
924 now predicted to spring-forward on April 30 instead of April 23.
926 Changes to past and future timestamps
928 Casey Station, Antarctica has been using +08 in winter and +11 in
929 summer since 2018. The most recent transition from +08 to +11 was
930 2020-10-04 00:01. Also, Macquarie Island has been staying in
931 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
933 Changes to past and future time zone abbreviations and DST flags
935 Canada's Yukon, represented by America/Whitehorse and
936 America/Dawson, changes its time zone rules from -08/-07 to
937 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
938 This change affects only the time zone abbreviation (MST vs PDT)
939 and daylight saving flag for the period between the two dates.
940 (Thanks to Andrew G. Smith.)
942 Changes to past timestamps
944 Correct several transitions for Hungary for 1918/1983.
945 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
946 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
947 time was on 11-01, not 10-01 (thanks to Michael Deckers).
949 The 1891 French transition was on March 16, not March 15. The
950 1911-03-11 French transition was at midnight, not a minute later.
951 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
952 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
956 Support for zic's long-obsolete '-y YEARISTYPE' option has been
957 removed and, with it, so has support for the TYPE field in Rule
958 lines, which is now reserved for compatibility with earlier zic.
959 These features were previously deprecated in release 2015f.
960 (Thanks to Tim Parenti.)
962 zic now defaults to '-b slim' instead of to '-b fat'.
964 zic's new '-l -' and '-p -' options uninstall any existing
965 localtime and posixrules files, respectively.
967 The undocumented and ineffective tzsetwall function has been
970 Changes to build procedure
972 The Makefile now defaults POSIXRULES to '-', so the posixrules
973 feature (obsolete as of 2019b) is no longer installed by default.
975 Changes to documentation and commentary
977 The long-obsolete files pacificnew, systemv, and yearistype.sh have
978 been removed from the distribution. (Thanks to Tim Parenti.)
981 Release 2020a - 2020-04-23 16:03:47 -0700
984 Morocco springs forward on 2020-05-31, not 2020-05-24.
985 Canada's Yukon advanced to -07 year-round on 2020-03-08.
986 America/Nuuk renamed from America/Godthab.
987 zic now supports expiration dates for leap second lists.
989 Changes to future timestamps
991 Morocco's second spring-forward transition in 2020 will be May 31,
992 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
993 Adjust future-year predictions to use the first Sunday after the
994 day after Ramadan, not the first Sunday after Ramadan.
996 Canada's Yukon, represented by America/Whitehorse and
997 America/Dawson, advanced to -07 year-round, beginning with its
998 spring-forward transition on 2020-03-08, and will not fall back on
999 2020-11-01. Although a government press release calls this
1000 "permanent Pacific Daylight Saving Time", we prefer MST for
1001 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
1002 (Thanks to Tim Parenti.)
1004 Changes to past timestamps
1006 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
1008 Changes to timezone identifiers
1010 To reflect current usage in English better, America/Godthab has
1011 been renamed to America/Nuuk. A backwards-compatibility link
1012 remains for the old name.
1016 localtime.c no longer mishandles timestamps after the last
1017 transition in a TZif file with leap seconds and with daylight
1018 saving time transitions projected into the indefinite future.
1019 For example, with TZ='America/Los_Angeles' with leap seconds,
1020 zdump formerly reported a DST transition on 2038-03-14
1021 from 01:59:32.999... to 02:59:33 instead of the correct transition
1022 from 01:59:59.999... to 03:00:00.
1024 zic -L now supports an Expires line in the leapseconds file, and
1025 truncates the TZif output accordingly. This propagates leap
1026 second expiration information into the TZif file, and avoids the
1027 abovementioned localtime.c bug as well as similar bugs present in
1028 many client implementations. If no Expires line is present, zic
1029 -L instead truncates the TZif output based on the #expires comment
1030 present in leapseconds files distributed by tzdb 2018f and later;
1031 however, this usage is obsolescent. For now, the distributed
1032 leapseconds file has an Expires line that is commented out, so
1033 that the file can be fed to older versions of zic which ignore the
1034 commented-out line. Future tzdb distributions are planned to
1035 contain a leapseconds file with an Expires line.
1037 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
1038 set to 1 if the system library supports the feature, and 2 if not.
1039 As before, these macros are nonzero if tzcode should support the
1040 feature, zero otherwise.
1042 The configuration macro ALTZONE now has the same values with the
1043 same meaning as HAVE_TZNAME and USG_COMPAT.
1045 The code's defense against CRLF in leap-seconds.list is now
1046 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
1048 Although the undocumented tzsetwall function is not changed in
1049 this release, it is now deprecated in preparation for removal in
1050 future releases. Due to POSIX requirements, tzsetwall has not
1051 worked for some time. Any code that uses it should instead use
1052 tzalloc(NULL) or, if portability trumps thread-safety, should
1053 unset the TZ environment variable.
1055 Changes to commentary
1057 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
1058 following America/Halifax, and comments about Yukon's "south" and
1059 "north" have been corrected to say "east" and "west". (Thanks to
1063 Release 2019c - 2019-09-11 08:59:48 -0700
1066 Fiji observes DST from 2019-11-10 to 2020-01-12.
1067 Norfolk Island starts observing Australian-style DST.
1069 Changes to future timestamps
1071 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
1072 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
1073 Adjust future guesses accordingly.
1075 Norfolk Island will observe Australian-style DST starting in
1076 spring 2019. The first transition is on 2019-10-06. (Thanks to
1077 Kyle Czech and Michael Deckers.)
1079 Changes to past timestamps
1081 Many corrections to time in Turkey from 1940 through 1985.
1082 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
1084 The Norfolk Island 1975-03-02 transition was at 02:00 standard
1085 time, not 02:00 DST. (Thanks to Michael Deckers.)
1087 South Korea observed DST from 1948 through 1951. Although this
1088 info was supposed to appear in release 2014j, a typo inadvertently
1089 suppressed the change. (Thanks to Alois Treindl.)
1091 Detroit observed DST in 1967 and 1968 following the US DST rules,
1092 except that its 1967 DST began on June 14 at 00:01. (Thanks to
1093 Alois Treindl for pointing out that the old data entries were
1096 Fix several errors in pre-1970 transitions in Perry County, IN.
1097 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
1099 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
1100 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
1101 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
1102 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
1103 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
1104 Königsberg switched to +03 on 04-07 not 01-01.
1106 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
1107 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
1108 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
1110 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
1111 (Thanks to Michael Deckers.)
1113 Changes to past time zone abbreviations and DST flags
1115 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
1116 is now flagged as DST and is abbreviated HKWT not HKT.
1120 leapseconds.awk now relies only on its input data, rather than
1121 also relying on its comments. (Inspired by code from Dennis
1122 Ferguson and Chris Woodbury.)
1124 The code now defends against CRLFs in leap-seconds.list.
1125 (Thanks to Brian Inglis and Chris Woodbury.)
1127 Changes to documentation and commentary
1129 theory.html discusses leap seconds. (Thanks to Steve Summit.)
1131 Nashville's newspapers dueled about the time of day in the 1950s.
1132 (Thanks to John Seigenthaler.)
1134 Liechtenstein observed Swiss DST in 1941/2.
1135 (Thanks to Alois Treindl.)
1138 Release 2019b - 2019-07-01 00:09:53 -0700
1141 Brazil no longer observes DST.
1142 'zic -b slim' outputs smaller TZif files; please try it out.
1143 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
1145 Changes to future timestamps
1147 Brazil has canceled DST and will stay on standard time indefinitely.
1148 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
1151 Predictions for Morocco now go through 2087 instead of 2037, to
1152 work around a problem on newlib when using TZif files output by
1153 zic 2019a or earlier. (Problem reported by David Gauchard.)
1155 Changes to past and future timestamps
1157 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
1158 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
1159 future transitions to be March's last Friday at 00:00.
1161 Changes to past timestamps
1163 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
1164 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
1165 not 09-15 at 00:00. In 1946 its spring-forward transition was on
1166 04-21 at 00:00, not the previous day at 03:30. From 1946 through
1167 1952 its fall-back transitions occurred at 04:30, not at 03:30.
1168 In 1947 its fall-back transition was on 11-30, not 12-30.
1171 Changes to past time zone abbreviations
1173 Italy's 1866 transition to Rome Mean Time was on December 12, not
1174 September 22. This affects only the time zone abbreviation for
1175 Europe/Rome between those dates. (Thanks to Stephen Trainor and
1178 Changes affecting metadata only
1180 Add info about the Crimea situation in zone1970.tab and zone.tab.
1181 (Problem reported by Serhii Demediuk.)
1185 zic's new -b option supports a way to control data bloat and to
1186 test for year-2038 bugs in software that reads TZif files.
1187 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
1188 for example, changing from fat to slim shrinks the Europe/London
1189 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
1190 files represent the same set of timestamps and use the same TZif
1191 format as documented in tzfile(5) and in Internet RFC 8536.
1192 Fat format attempts to work around bugs or incompatibilities in
1193 older software, notably software that mishandles 64-bit TZif data
1194 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
1195 Slim format is more efficient and does not work around 64-bit bugs
1196 or obsolete TZ strings. Currently zic defaults to fat format
1197 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
1198 out-of-the-box default is intended to change in future releases
1199 as the buggy software often mishandles timestamps anyway.
1201 zic no longer treats a set of rules ending in 2037 specially.
1202 Previously, zic assumed that such a ruleset meant that future
1203 timestamps could not be predicted, and therefore omitted a
1204 POSIX-like TZ string in the TZif output. The old behavior is no
1205 longer needed for current tzdata, and caused problems with newlib
1206 when used with older tzdata (reported by David Gauchard).
1208 zic no longer generates some artifact transitions. For example,
1209 Europe/London no longer has a no-op transition in January 1996.
1211 Changes to build procedure
1213 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
1216 Changes to documentation and commentary
1218 The Makefile now documents the POSIXRULES macro as being obsolete,
1219 and similarly, zic's -p POSIXRULES option is now documented as
1220 being obsolete. Although the POSIXRULES feature still exists and
1221 works as before, in practice it is rarely used for its intended
1222 purpose, and it does not work either in the default reference
1223 implementation (for timestamps after 2037) or in common
1224 implementations such as GNU/Linux (for contemporary timestamps).
1225 Since POSIXRULES was designed primarily as a temporary transition
1226 facility for System V platforms that died off decades ago, it is
1227 being decommissioned rather than institutionalized.
1229 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
1232 Release 2019a - 2019-03-25 22:01:33 -0700
1235 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
1236 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
1238 Changes to past and future timestamps
1240 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
1241 previously predicted. Adjust our prediction by guessing that spring
1242 transitions will be between 24 and 30 March, which matches recent practice
1243 since 2016. (Thanks to Even Scharning and Tim Parenti.)
1245 Metlakatla ended its observance of Pacific standard time,
1246 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
1247 Stanley and Tim Parenti.)
1249 Changes to past timestamps
1251 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
1252 (Thanks to Alois Treindl and Isaac Starkman.)
1254 Changes to time zone abbreviations
1256 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
1257 of being a separate zone that generates the abbreviation "UCT",
1258 which nowadays is typically a typo. (Problem reported by Isiah
1263 zic now has an -r option to limit the time range of output data.
1264 For example, 'zic -r @1000000000' limits the output data to
1265 timestamps starting 1000000000 seconds after the Epoch.
1266 This helps shrink output size and can be useful for applications
1267 not needing the full timestamp history, such as TZDIST truncation;
1268 see Internet RFC 8536 section 5.1. (Inspired by a feature request
1269 from Christopher Wong, helped along by bug reports from Wong and
1272 Changes to documentation
1274 Mention Internet RFC 8536 (February 2019), which documents TZif.
1276 tz-link.html now cites tzdata-meta
1277 <https://tzdata-meta.timtimeonline.com/>.
1280 Release 2018i - 2018-12-30 11:05:43 -0800
1283 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
1285 Changes to future timestamps
1287 Due to a change in government, São Tomé and Príncipe switches back
1288 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
1289 Nasardinov and Michael Deckers.)
1292 Release 2018h - 2018-12-23 17:59:32 -0800
1295 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
1296 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
1297 Metlakatla, Alaska observes PST this winter only.
1298 Guess Morocco will continue to adjust clocks around Ramadan.
1299 Add predictions for Iran from 2038 through 2090.
1301 Changes to future timestamps
1303 Guess that Morocco will continue to fall back just before and
1304 spring forward just after Ramadan, the practice since 2012.
1305 (Thanks to Maamar Abdelkader.) This means Morocco will observe
1306 negative DST during Ramadan in main and vanguard formats, and in
1307 rearguard format it stays in the +00 timezone and observes
1308 ordinary DST in all months other than Ramadan. As before, extend
1309 this guesswork to the year 2037. As a consequence, Morocco is
1310 scheduled to observe three DST transitions in some Gregorian years
1311 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
1314 The table of exact transitions for Iranian DST has been extended.
1315 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
1316 It now cuts off before 2091 as there is doubt about how the Persian
1317 calendar will treat 2091. This change predicts DST transitions in
1318 2038-9, 2042-3, and 2046-7 to occur one day later than previously
1319 predicted. As before, post-cutoff transitions are approximated.
1321 Changes to past and future timestamps
1323 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
1324 +05 on 2018-12-21. This is a zone split as Qostanay (aka
1325 Kostanay) did not switch, so create a zone Asia/Qostanay.
1327 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
1328 It did not change clocks that day and remains on -08 this winter.
1329 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
1330 rules next spring, so this change affects only timestamps
1331 from 2018-11-04 through 2019-03-10.
1333 Change to past timestamps
1335 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
1336 not 00:00. I transcribed the time incorrectly from Shanks.
1337 (Thanks to Phake Nick.)
1339 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
1340 (Thanks to Phake Nick.)
1342 Guam observed DST irregularly from 1959 through 1977.
1343 (Thanks to Phake Nick.)
1345 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
1346 10-01 changed standard time to +08:30 (not +08). Its transition
1347 back to +08 after WWII was on 1945-09-15, not the previous day.
1348 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
1349 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1350 its 1952 fallback was on 11-02 (not 10-25).
1352 This release contains many changes to timestamps before 1946 due
1353 to Japanese possession or occupation of Pacific/Chuuk,
1354 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1355 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1356 (Thanks to Phake Nick.)
1358 Assume that the Spanish East Indies was like the Philippines and
1359 observed American time until the end of 1844. This affects
1360 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1362 Changes to past tm_isdst flags
1364 For the recent Morocco change, the tm_isdst flag should be 1 from
1365 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1366 Give a URL to the official decree. (Thanks to Matt Johnson.)
1369 Release 2018g - 2018-10-26 22:22:45 -0700
1372 Morocco switches to permanent +01 on 2018-10-28.
1374 Changes to future timestamps
1376 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1377 so its clocks will not fall back as previously scheduled.
1378 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1382 When generating TZif files with leap seconds, zic no longer uses a
1383 format that trips up older 32-bit clients, fixing a bug introduced
1384 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1385 for QTBUG-53071 now also works for TZif files with leap seconds.
1387 The translator to rearguard format now rewrites the line
1388 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1389 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1390 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1391 and earlier. (Reported by Christos Zoulas.)
1393 Changes to past time zone abbreviations
1395 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1396 This reverts to 2011h, as the abbreviation change in 2011i was
1399 Changes to documentation
1401 tzfile.5 has new sections on interoperability issues.
1404 Release 2018f - 2018-10-18 00:14:18 -0700
1407 Volgograd moves from +03 to +04 on 2018-10-28.
1408 Fiji ends DST 2019-01-13, not 2019-01-20.
1409 Most of Chile changes DST dates, effective 2019-04-06.
1411 Changes to future timestamps
1413 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1414 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1416 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1417 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1420 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1421 time, and resume DST on the first Saturday in September at 24:00 mainland
1422 time. The changes are effective from 2019-04-06, and do not affect the
1423 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1424 and Tim Parenti.) Adjust future predictions accordingly.
1426 Changes to past timestamps
1428 The 2018-05-05 North Korea 30-minute time zone change took place
1429 at 23:30 the previous day, not at 00:00 that day.
1431 China's 1988 spring-forward transition was on April 17, not
1432 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1435 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1436 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1437 temporarily switched to +09/+10 during World War II. Macau
1438 observed DST in 1942/79, not 1961/80, and there were several
1439 errors for transition times and dates. (Thanks to P Chan.)
1441 The 1948-1951 fallback transitions in Japan were at 25:00 on
1442 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1443 zic turns this into 01:00 on the day after September's second
1444 Saturday, which is the best that POSIX or C platforms can do.
1446 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1447 paper by Li Yu, replacing more-questionable data from Shanks.
1449 Changes to time zone abbreviations
1451 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1455 zic now always generates TZif files where time type 0 is used for
1456 timestamps before the first transition. This simplifies the
1457 reading of TZif files and should not affect behavior of existing
1458 TZif readers because the same set of time types is used; only
1459 their internal indexes may have changed. This affects only the
1460 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1461 EET, which previously used nonzero types for these timestamps.
1463 Because of the type 0 change, zic no longer outputs a dummy
1464 transition at time -2**59 (before the Big Bang), as clients should
1465 no longer need this to handle historical timestamps correctly.
1466 This reverts a change introduced in 2013d and shrinks most TZif
1467 files by a few bytes.
1469 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1470 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1471 occurs at 18:00 on the Saturday before the last Sunday in April.
1472 This behavior was documented in 2018a but the code did not
1473 entirely match the documentation.
1475 localtime.c no longer requires at least one time type in TZif
1476 files that lack transitions or have a POSIX-style TZ string. This
1477 future-proofs the code against possible future extensions to the
1478 format that would allow TZif files with POSIX-style TZ strings and
1479 without transitions or time types.
1481 A read-access subscript error in localtime.c has been fixed.
1482 It could occur only in TZif files with timecnt == 0, something that
1483 does not happen in practice now but could happen in future versions.
1485 localtime.c no longer ignores TZif POSIX-style TZ strings that
1486 specify only standard time. Instead, these TZ strings now
1487 override the default time type for timestamps after the last
1488 transition (or for all timestamps if there are no transitions),
1489 just as DST strings specifying DST have always done.
1491 leapseconds.awk now outputs "#updated" and "#expires" comments,
1492 and supports leap seconds at the ends of months other than June
1493 and December. (Inspired by suggestions from Chris Woodbury.)
1495 Changes to documentation
1497 New restrictions: A Rule name must start with a character that
1498 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1499 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1500 The latter restriction makes room for future extensions (a
1501 possibility noted by Tom Lane).
1503 tzfile.5 now documents what time types apply before the first and
1504 after the last transition, if any.
1506 Documentation now uses the spelling "timezone" for a TZ setting
1507 that determines timestamp history, and "time zone" for a
1508 geographic region currently sharing the same standard time.
1510 The name "TZif" is now used for the tz binary data format.
1512 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1513 (Thanks to Aldrin Martoq for the link.)
1515 Changes to build procedure
1517 New 'make' target 'rearguard_tarballs' to build the rearguard
1518 tarball only. This is a convenience on platforms that lack lzip
1519 if you want to build the rearguard tarball. (Problem reported by
1522 tzdata.zi is now more stable from release to release. (Problem
1523 noted by Tom Lane.) It is also a bit shorter.
1525 tzdata.zi now can contain comment lines documenting configuration
1526 information, such as which data format was selected, which input
1527 files were used, and how leap seconds are treated. (Problems
1528 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1529 are used these comment lines are absent, for backward
1530 compatibility. A redistributor intending to alter its copy of the
1531 files should also append "-LABEL" to the 'version' file's first
1532 line, where "LABEL" identifies the redistributor's change.
1535 Release 2018e - 2018-05-01 23:42:51 -0700
1539 North Korea switches back to +09 on 2018-05-05.
1540 The main format uses negative DST again, for Ireland etc.
1541 'make tarballs' now also builds a rearguard tarball.
1542 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1544 Changes to past and future timestamps
1546 North Korea switches back from +0830 to +09 on 2018-05-05.
1547 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1550 Bring back the negative-DST changes of 2018a, except be more
1551 compatible with data parsers that do not support negative DST.
1552 Also, this now affects historical timestamps in Namibia and the
1553 former Czechoslovakia, not just Ireland. The main format now uses
1554 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1555 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1556 does not affect UT offsets, only time zone abbreviations and the
1557 tm_isdst flag. Also, this does not affect rearguard or vanguard
1558 formats; effectively the main format now uses vanguard instead of
1559 rearguard format. Data parsers that do not support negative DST
1560 can still use data from the rearguard tarball described below.
1562 Changes to build procedure
1564 The command 'make tarballs' now also builds the tarball
1565 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1566 except that it uses rearguard format intended for trailing-edge
1569 Changes to data format and to code
1571 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1572 suffix, which specifies whether the adjusted time is standard time
1573 or daylight saving time. If no suffix is given, daylight saving
1574 time is used if and only if the SAVE column is nonzero; this is
1575 the longstanding behavior. Although this new feature is not used
1576 in tzdata, it could be used to specify the legal time in Namibia
1577 1994-2017, as opposed to the popular time (see below).
1579 Changes to past timestamps
1581 From 1994 through 2017 Namibia observed DST in winter, not summer.
1582 That is, it used negative DST, as Ireland still does. This change
1583 does not affect UTC offsets; it affects only the tm_isdst flag and
1584 the abbreviation used during summer, which is now CAT, not WAST.
1585 Although (as noted by Michael Deckers) summer and winter time were
1586 both simply called "standard time" in Namibian law, in common
1587 practice winter time was considered to be DST (as noted by Stephen
1588 Colebourne). The full effect of this change is only in vanguard
1589 and main format; in rearguard format, the tm_isdst flag is still
1590 zero in winter and nonzero in summer.
1592 In 1946/7 Czechoslovakia also observed negative DST in winter.
1593 The full effect of this change is only in vanguard and main
1594 formats; in rearguard format, it is modeled as plain GMT without
1595 daylight saving. Also, the dates of some 1944/5 DST transitions
1596 in Czechoslovakia have been changed.
1599 Release 2018d - 2018-03-22 07:05:46 -0700
1603 Palestine starts DST a week earlier in 2018.
1604 Add support for vanguard and rearguard data consumers.
1605 Add subsecond precision to source data format, though not to data.
1607 Changes to future timestamps
1609 In 2018, Palestine starts DST on March 24, not March 31.
1610 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1612 Changes to past and future timestamps
1614 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1615 at 04:00. (Thanks to Steffen Thorsen.)
1617 Changes to past timestamps
1619 Historical transitions for Uruguay, represented by
1620 America/Montevideo, have been updated per official legal documents,
1621 replacing previous data mainly originating from the inventions of
1622 Shanks & Pottenger. This has resulted in adjustments ranging from
1623 30 to 90 minutes in either direction over at least two dozen
1624 distinct periods ranging from one day to several years in length.
1625 A mere handful of pre-1991 transitions are unaffected; data since
1626 then has come from more reliable contemporaneous reporting. These
1627 changes affect various timestamps in 1920-1923, 1936, 1939,
1628 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1629 Additionally, Uruguay's pre-standard-time UT offset has been
1630 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1631 match the location of the Observatory of the National Meteorological
1632 Institute in Montevideo.
1633 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1635 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1636 (Thanks to Kerry Shetline.)
1638 Fix the 1912-01-01 transition for Portugal and its colonies.
1639 This transition was at 00:00 according to the new UT offset, not
1640 according to the old one. Also assume that Cape Verde switched on
1641 the same date as the rest, not in 1907. This affects
1642 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1643 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1644 (Thanks to Michael Deckers.)
1646 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1649 Changes to past time zone abbreviations
1651 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1652 is no clock change associated with the transition.
1654 Changes to build procedure
1656 The new DATAFORM macro in the Makefile lets the installer choose
1657 among three source data formats. The idea is to lessen downstream
1658 disruption when data formats are improved.
1660 * DATAFORM=vanguard installs from the latest, bleeding-edge
1661 format. DATAFORM=main (the default) installs from the format
1662 used in the 'africa' etc. files. DATAFORM=rearguard installs
1663 from a trailing-edge format. Eventually, elements of today's
1664 vanguard format should move to the main format, and similarly
1665 the main format's features should eventually move to the
1668 * In the current version, the main and rearguard formats are
1669 identical and match that of 2018c, so this change does not
1670 affect default behavior. The vanguard format currently contains
1671 one feature not in the main format: negative SAVE values. This
1672 improves support for Ireland, which uses Irish Standard Time
1673 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1674 supported negative SAVE values for decades, and this feature
1675 should move to the main format soon. However, it will not move
1676 to the rearguard format for quite some time because some
1677 downstream parsers do not support it.
1679 * The build procedure constructs three files vanguard.zi, main.zi,
1680 and rearguard.zi, one for each format. Although the files
1681 represent essentially the same data, they may have minor
1682 discrepancies that users are not likely to notice. The files
1683 are intended for downstream data consumers and are not
1684 installed. Zoneinfo parsers that do not support negative SAVE values
1685 should start using rearguard.zi, so that they will be unaffected
1686 when the negative-DST feature moves from vanguard to main.
1687 Bleeding-edge Zoneinfo parsers that support the new features
1688 already can use vanguard.zi; in this respect, current tzcode is
1691 The Makefile should now be safe for parallelized builds, and 'make
1692 -j to2050new.tzs' is now much faster on a multiprocessor host
1695 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1696 prepends TZDIR/ to file names that do not begin with '/'. This is
1697 not recommended for general use, due to its security implications.
1698 (From a suggestion by Manuela Friedrich.)
1702 zic now accepts subsecond precision in expressions like
1703 00:19:32.13, which is approximately the legal time of the
1704 Netherlands from 1835 to 1937. However, because it is
1705 questionable whether the few recorded uses of non-integer offsets
1706 had subsecond precision in practice, there are no plans for tzdata
1707 to use this feature. (Thanks to Steve Allen for pointing out
1708 the limitations of historical data in this area.)
1710 The code is a bit more portable to MS-Windows. Installers can
1711 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1712 reserve identifiers like 'localtime'. (Thanks to Manuela
1715 Changes to documentation and commentary
1717 theory.html now outlines tzdb's extensions to POSIX's model for
1718 civil time, and has a section "POSIX features no longer needed"
1719 that lists POSIX API components that are now vestigial.
1720 (From suggestions by Steve Summit.) It also better distinguishes
1721 time zones from tz regions. (From a suggestion by Guy Harris.)
1723 Commentary is now more consistent about using the phrase "daylight
1724 saving time", to match the C name tm_isdst. Daylight saving time
1725 need not occur in summer, and need not have a positive offset from
1728 Commentary about historical transitions in Uruguay has been expanded
1729 with links to many relevant legal documents.
1730 (Thanks to Tim Parenti.)
1732 Commentary now uses some non-ASCII characters with Unicode value
1733 less than U+0100, as they can be useful and should work even with
1734 older editors such as XEmacs.
1737 Release 2018c - 2018-01-22 23:00:44 -0800
1740 Revert Irish changes that relied on negative SAVE values.
1744 Revert the 2018a change to Europe/Dublin. As before, this change
1745 does not affect UT offsets or abbreviations; it affects only
1746 whether timestamps are considered to be standard time or
1747 daylight-saving time, as expressed in the tm_isdst flag of C's
1748 struct tm type. This reversion is intended to be a temporary
1749 workaround for problems discovered with downstream uses of
1750 releases 2018a and 2018b, which implemented Irish time by using
1751 negative SAVE values in the Eire rules of the 'europe' file.
1752 Although negative SAVE values have been part of tzcode for many
1753 years and are supported by many platforms, they were not
1754 documented before 2018a and ICU and OpenJDK do not currently
1755 support them. A mechanism to export data to platforms lacking
1756 support for negative DST is planned to be developed before the
1757 change is reapplied. (Problems reported by Deborah Goldsmith and
1758 Stephen Colebourne.)
1760 Changes to past timestamps
1762 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1763 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1765 Changes to build procedure
1767 The build procedure now works around mawk 1.3.3's lack of support
1768 for character class expressions. (Problem reported by Ohyama.)
1771 Release 2018b - 2018-01-17 23:24:48 -0800
1774 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1776 Changes to build procedure
1778 The distribution now contains the file 'pacificnew' again.
1779 This file was inadvertently omitted in the 2018a distribution.
1780 (Problem reported by Matias Fonzo.)
1783 Release 2018a - 2018-01-12 22:29:21 -0800
1786 São Tomé and Príncipe switched from +00 to +01.
1787 Brazil's DST will now start on November's first Sunday.
1788 Ireland's standard time is now in the summer, not the winter.
1789 Use Debian-style installation locations, instead of 4.3BSD-style.
1792 Changes to past and future timestamps
1794 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1795 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1797 Changes to future timestamps
1799 Starting in 2018 southern Brazil will begin DST on November's
1800 first Sunday instead of October's third Sunday. (Thanks to
1803 Changes to past timestamps
1805 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1806 been corrected. The 'backzone' and 'zone.tab' files did not agree
1807 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1810 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1811 BST instead of BOST, to be more consistent with the convention
1812 used for Latvian Summer Time (1918-9) and for British Summer Time.
1816 Change Europe/Dublin so that it observes Irish Standard Time (UT
1817 +01) in summer and GMT (as negative daylight-saving) in winter,
1818 instead of observing standard time (GMT) in winter and Irish
1819 Summer Time (UT +01) in summer. This change does not affect UT
1820 offsets or abbreviations; it affects only whether timestamps are
1821 considered to be standard time or daylight-saving time, as
1822 expressed in the tm_isdst flag of C's struct tm type.
1823 (Discrepancy noted by Derick Rethans.)
1825 Changes to build procedure
1827 The default installation locations have been changed to mostly
1828 match Debian circa 2017, instead of being designed as an add-on to
1829 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1830 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1831 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1832 locations more precisely. (This responds to suggestions from
1833 Brian Inglis and from Steve Summit.)
1835 The default installation procedure no longer creates the
1836 backward-compatibility link US/Pacific-New, which causes
1837 confusion during user setup (e.g., see Debian bug 815200).
1838 Use 'make BACKWARD="backward pacificnew"' to create the link
1839 anyway, for now. Eventually we plan to remove the link entirely.
1841 tzdata.zi now contains a version-number comment.
1842 (Suggested by Tom Lane.)
1844 The Makefile now quotes values like BACKWARD more carefully when
1845 passing them to the shell. (Problem reported by Zefram.)
1847 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1848 that have snprintf and use pre-C99 compilers. (Problem reported
1853 zic has a new option -t FILE that specifies the location of the
1854 file that determines local time when TZ is unset. The default for
1855 this location can be configured via the new TZDEFAULT makefile
1856 macro, which defaults to /etc/localtime.
1858 Diagnostics and commentary now distinguish UT from UTC more
1859 carefully; see theory.html for more information about UT vs UTC.
1861 zic has been ported to GCC 8's -Wstringop-truncation option.
1862 (Problem reported by Martin Sebor.)
1864 Changes to documentation and commentary
1866 The zic man page now documents the longstanding behavior that
1867 times and years can be out of the usual range, with negative times
1868 counting backwards from midnight and with year 0 preceding year 1.
1869 (Problem reported by Michael Deckers.)
1871 The theory.html file now mentions the POSIX limit of six chars
1872 per abbreviation, and lists alphabetic abbreviations used.
1874 The files tz-art.htm and tz-link.htm have been renamed to
1875 tz-art.html and tz-link.html, respectively, for consistency with
1876 other file names and to simplify web server configuration.
1879 Release 2017c - 2017-10-20 14:49:34 -0700
1882 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1883 Fiji ends DST 2018-01-14, not 2018-01-21.
1884 Namibia switches from +01/+02 to +02 on 2018-04-01.
1885 Sudan switches from +03 to +02 on 2017-11-01.
1886 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1887 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1888 A new file tzdata.zi now holds a small text copy of all data.
1889 The zic input format has been regularized slightly.
1891 Changes to future timestamps
1893 Northern Cyprus has decided to resume EU rules starting
1894 2017-10-29, thus reinstituting winter time.
1896 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1897 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1900 Namibia will switch from +01 with DST to +02 all year on
1901 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1902 at 02:00. (Thanks to Steffen Thorsen.)
1904 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1905 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1906 Africa/Juba is no longer a link to Africa/Khartoum.
1908 Tonga has likely ended its experiment with DST, and will not
1909 adjust its clocks on 2017-11-05. Although Tonga has not announced
1910 whether it will continue to observe DST, the IATA is assuming that
1911 it will not. (Thanks to David Wade.)
1913 Turks & Caicos will switch from -04 all year to -05 with US DST on
1914 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1915 at 02:00. (Thanks to Steffen Thorsen.)
1917 Changes to past timestamps
1919 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1920 (Thanks to Arthur David Olson.)
1922 Detroit did not observe DST in 1967.
1924 Use railway time for Asia/Kolkata before 1941, by switching to
1925 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1926 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1928 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1929 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1931 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1932 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1934 Adjust the 1867 transition in Alaska to better reflect the
1935 historical record, by changing it to occur on 1867-10-18 at 15:30
1936 Sitka time rather than at the start of 1867-10-17 local time.
1937 Although strictly speaking this is accurate only for Sitka,
1938 the rest of Alaska's blanks need to be filled in somehow.
1940 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1941 (Thanks to Michael Deckers.)
1943 Add 7 s to the UT offset in Asia/Yangon before 1920.
1945 Changes to zone names
1947 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1948 exceeded the 14-character limit and was an unused misnomer anyway.
1950 Changes to build procedure
1952 To support applications that prefer to read time zone data in text
1953 form, two zic input files tzdata.zi and leapseconds are now
1954 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1955 leapseconds tzdata.zi' can reproduce the tzdata binary files
1956 without and with leap seconds, respectively. To prevent these two
1957 new files from being installed, use 'make TZDATA_TEXT=', and to
1958 suppress leap seconds from the tzdata text installation, use 'make
1959 TZDATA_TEXT=tzdata.zi'.
1961 'make BACKWARD=' now suppresses backward-compatibility names
1962 like 'US/Pacific' that are defined in the 'backward' and
1965 'make check' now works on systems that lack a UTF-8 locale,
1966 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1967 the name of a UTF-8 locale, if you have one.
1969 Y2K runtime checks are no longer enabled by default. Add
1970 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1971 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1972 to disable them. (New name suggested by Brian Inglis.)
1974 The build procedure for zdump now works on AIX 7.1.
1975 (Problem reported by Kees Dekker.)
1979 zic and the reference runtime now reject multiple leap seconds
1980 within 28 days of each other, or leap seconds before the Epoch.
1981 As a result, support for double leap seconds, which was
1982 obsolescent and undocumented, has been removed. Double leap
1983 seconds were an error in the C89 standard; they have never existed
1984 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1985 noticing glitches in the code that uncovered this problem.)
1987 zic now warns about use of the obsolescent and undocumented -y
1988 option, and about use of the obsolescent TYPE field of Rule lines.
1990 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1991 weekdays; formerly it rejected them due to a bug. Conversely, zic
1992 no longer considers non-prefixes to be abbreviations; for example,
1993 it no longer accepts "lF" as an abbreviation for "lastFriday".
1994 Also, zic warns about the undocumented usage with a "last-"
1995 prefix, e.g., "last-Fri".
1997 Similarly, zic now accepts the unambiguous abbreviation "L" for
1998 "Link" in ordinary context and for "Leap" in leap-second context.
1999 Conversely, zic no longer accepts non-prefixes such as "La" as
2000 abbreviations for words like "Leap".
2002 zic no longer accepts leap second lines in ordinary input, or
2003 ordinary lines in leap second input. Formerly, zic sometimes
2004 warned about this undocumented usage and handled it incorrectly.
2006 The new macro HAVE_TZNAME governs whether the tzname external
2007 variable is exported, instead of USG_COMPAT. USG_COMPAT now
2008 governs only the external variables "timezone" and "daylight".
2009 This change is needed because the three variables are not in the
2010 same category: although POSIX requires tzname, it specifies the
2011 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
2012 if not defined, the code attempts to guess it from other macros.
2014 localtime.c and difftime.c no longer require stdio.h, and .c files
2015 other than zic.c no longer require sys/wait.h.
2017 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
2019 Calculation of time_t extrema works around a bug in GCC 4.8.4
2020 (Reported by Stan Shebs and Joseph Myers.)
2022 zic.c no longer mistranslates formats of line numbers in non-English
2023 locales. (Problem reported by Benno Schulenberg.)
2025 Several minor changes have been made to the code to make it a
2026 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
2027 Dekker for reporting the problems.)
2029 Changes to documentation and commentary
2031 The two new files 'theory.html' and 'calendars' contain the
2032 contents of the removed file 'Theory'. The goal is to document
2033 tzdb theory more accessibly.
2035 The zic man page now documents abbreviation rules.
2037 tz-link.htm now covers how to apply tzdata changes to clients.
2038 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
2040 The leap-seconds.list URL has been updated to something that is
2041 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
2043 Release 2017b - 2017-03-17 07:30:38 -0700
2045 Briefly: Haiti has resumed DST.
2047 Changes to past and future timestamps
2049 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
2051 Changes to past timestamps
2053 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
2055 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
2056 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
2060 The reference localtime implementation now falls back on the
2061 current US daylight-saving transition rules rather than the
2062 1987-2006 rules. This fallback occurs only when (1) the TZ
2063 environment variable has a value like "AST4ADT" that asks
2064 for daylight saving time but does not specify the rules, (2) there
2065 is no file by that name, and (3) the TZDEFRULES file cannot be
2066 loaded. (Thanks to Tom Lane.)
2069 Release 2017a - 2017-02-28 00:05:36 -0800
2071 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
2074 Changes to future timestamps
2076 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
2078 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
2079 Its clocks diverge from America/Santiago starting 2017-05-13 at
2080 23:00, hiving off a new zone America/Punta_Arenas. Although the
2081 Chilean government says this change expires in May 2019, for now
2082 assume it's permanent. (Thanks to Juan Correa and Deborah
2083 Goldsmith.) This also affects Antarctica/Palmer.
2085 Changes to past timestamps
2087 Fix many entries for historical timestamps for Europe/Madrid
2088 before 1979, to agree with tables compiled by Pere Planesas of the
2089 National Astronomical Observatory of Spain. As a side effect,
2090 this changes some timestamps for Africa/Ceuta before 1929, which
2091 are probably guesswork anyway. (Thanks to Steve Allen and
2092 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
2093 correcting the 1901 transition.)
2095 Ecuador observed DST from 1992-11-28 to 1993-02-05.
2096 (Thanks to Alois Treindl.)
2098 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
2099 (Thanks to Stepan Golosunov.)
2101 Changes to past and future time zone abbreviations
2103 Switch to numeric time zone abbreviations for South America, as
2104 part of the ongoing project of removing invented abbreviations.
2105 This avoids the need to invent an abbreviation for the new Chilean
2106 new zone. Similarly, switch from invented to numeric time zone
2107 abbreviations for Afghanistan, American Samoa, the Azores,
2108 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
2109 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
2110 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
2111 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
2112 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
2113 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
2114 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
2115 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
2116 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
2117 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
2118 for half-hour daylight saving time in Belize before 1944 and in
2119 the Dominican Republic before 1975; and for Canary Islands before
2120 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
2121 Indian Summer Time before 1942, for Indonesia before around 1964,
2122 for Kenya before 1960, for Liberia before 1973, for Madeira before
2123 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
2124 Pakistan before 1971, for Western Sahara before 1977, and for
2125 Zaporozhye in 1880-1924.
2127 For Alaska time from 1900 through 1967, instead of "CAT" use the
2128 abbreviation "AST", the abbreviation commonly used at the time
2129 (Atlantic Standard Time had not been standardized yet). Use "AWT"
2130 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
2132 Use "CST" and "CDT" instead of invented abbreviations for Macau
2133 before 1999 and Taiwan before 1938, and use "JST" instead of the
2134 invented abbreviation "JCST" for Japan and Korea before 1938.
2136 Change to database entry category
2138 Move the Pacific/Johnston link from 'australasia' to 'backward',
2139 since Johnston is now uninhabited.
2143 zic no longer mishandles some transitions in January 2038 when it
2144 attempts to work around Qt bug 53071. This fixes a bug affecting
2145 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
2146 now contains a workaround, useful when loading a file generated by
2147 a buggy zic. (Problem and localtime.c fix reported by Bradley
2150 zdump -i now outputs non-hour numeric time zone abbreviations
2151 without a colon, e.g., "+0530" rather than "+05:30". This agrees
2152 with zic %z and with common practice, and simplifies auditing of
2155 zdump is now buildable again with -DUSE_LTZ=0.
2156 (Problem reported by Joseph Myers.)
2158 zdump.c now always includes private.h, to avoid code duplication
2159 with private.h. (Problem reported by Kees Dekker.)
2161 localtime.c no longer mishandles early or late timestamps
2162 when TZ is set to a POSIX-style string that specifies DST.
2163 (Problem reported by Kees Dekker.)
2165 date and strftime now cause %z to generate "-0000" instead of
2166 "+0000" when the UT offset is zero and the time zone abbreviation
2169 Changes to documentation and commentary
2171 The 'Theory' file now better documents choice of historical time
2172 zone abbreviations. (Problems reported by Michael Deckers.)
2174 tz-link.htm now covers leap smearing, which is popular in clouds.
2177 Release 2016j - 2016-11-22 23:17:13 -0800
2179 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
2181 Changes to future timestamps
2183 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
2184 This hives off a new zone Europe/Saratov from Europe/Volgograd.
2185 (Thanks to Yuri Konotopov and Stepan Golosunov.)
2187 Changes to past timestamps
2189 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
2190 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
2191 1999, not fall 1994. (Thanks to Stepan Golosunov.)
2193 Changes to past time zone abbreviations
2195 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
2196 summer time before 1948. The old use of "EET" was a typo.
2200 zic no longer mishandles file systems that lack hard links, fixing
2201 bugs introduced in 2016g. (Problems reported by Tom Lane.)
2202 Also, when the destination already contains symbolic links, zic
2203 should now work better on systems where the 'link' system call
2204 does not follow symbolic links.
2206 Changes to documentation and commentary
2208 tz-link.htm now documents the relationship between release version
2209 numbers and development-repository commit tags. (Suggested by
2212 The 'Theory' file now documents UT.
2214 iso3166.tab now accents "Curaçao", and commentary now mentions
2215 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
2218 Release 2016i - 2016-11-01 23:19:52 -0700
2220 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
2221 reintroduces DST on 2016-11-06.
2223 Changes to future timestamps
2225 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
2226 2017-01-15 at 03:00. Assume future observances in Tonga will be
2227 from the first Sunday in November through the third Sunday in
2228 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
2229 time zone abbreviations for this zone.
2231 Changes to past and future timestamps
2233 Northern Cyprus is now +03 year round, causing a split in Cyprus
2234 time zones starting 2016-10-30 at 04:00. This creates a zone
2235 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
2237 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
2238 (Thanks to Steffen Thorsen.)
2240 Changes to past timestamps
2242 Several corrections were made for pre-1975 timestamps in Italy.
2243 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
2246 First, the 1893-11-01 00:00 transition in Italy used the new UT
2247 offset (+01), not the old (+00:49:56). (Thanks to Michael
2250 Second, rules for daylight saving in Italy were changed to agree
2251 with Italy's National Institute of Metrological Research (INRiM)
2252 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
2253 Inglis, and Michael Deckers):
2255 The 1916-06-03 transition was at 24:00, not 00:00.
2257 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
2260 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
2263 The 1944-09-17 transition was at 03:00, not 01:00. This
2264 particular change is taken from Italian law as INRiM's table,
2265 (which says 02:00) appears to have a typo here. Also, keep the
2266 1944-04-03 transition for Europe/Rome, as Rome was controlled by
2269 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
2274 The code should now be buildable on AmigaOS merely by setting the
2275 appropriate Makefile variables. (From a patch by Carsten Larsen.)
2278 Release 2016h - 2016-10-19 23:17:57 -0700
2280 Changes to future timestamps
2282 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2283 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
2284 future fall transitions will be on the last Saturday of October
2285 at 01:00, which is consistent with predicted spring transitions
2286 on the last Saturday of March. (Thanks to Tim Parenti.)
2288 Changes to past timestamps
2290 In Turkey, transitions in 1986-1990 were at 01:00 standard time
2291 not at 02:00, and the spring 1994 transition was on March 20, not
2292 March 27. (Thanks to Kıvanç Yazan.)
2294 Changes to past and future time zone abbreviations
2296 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
2297 instead of alphabetic ones like "IST" and "LKT". Various
2298 English-language sources use "IST", "LKT" and "SLST", with no
2299 working consensus. (Usage of "SLST" mentioned by Sadika
2304 zic no longer mishandles relativizing file names when creating
2305 symbolic links like /etc/localtime, when these symbolic links
2306 are outside the usual directory hierarchy. This fixes a bug
2307 introduced in 2016g. (Problem reported by Andreas Stieger.)
2309 Changes to build procedure
2311 New rules 'traditional_tarballs' and 'traditional_signatures' for
2312 building just the traditional-format distribution. (Requested by
2315 The file 'version' is now put into the tzdata tarball too.
2316 (Requested by Howard Hinnant.)
2318 Changes to documentation and commentary
2320 The 'Theory' file now has a section on interface stability.
2321 (Requested by Paul Koning.) It also mentions features like
2322 tm_zone and localtime_rz that have long been supported by the
2325 tz-link.htm has improved coverage of time zone boundaries suitable
2326 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
2329 The US commentary now mentions Allen and the "day of two noons".
2331 The Fiji commentary mentions the government's 2016-10-03 press
2332 release. (Thanks to Raymond Kumar.)
2335 Release 2016g - 2016-09-13 08:56:38 -0700
2337 Changes to future timestamps
2339 Turkey switched from EET/EEST (+02/+03) to permanent +03,
2340 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
2341 than an invented abbreviation for the new time.
2343 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
2344 (Thanks to Tim Parenti.)
2346 Changes to past timestamps
2348 For America/Los_Angeles, spring-forward transition times have been
2349 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2352 For zones using Soviet time on 1919-07-01, transitions to UT-based
2353 time were at 00:00 UT, not at 02:00 local time. The affected
2354 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2355 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2357 Changes to past and future time zone abbreviations
2359 The Factory zone now uses the time zone abbreviation -00 instead
2360 of a long English-language string, as -00 is now the normal way to
2361 represent an undefined time zone.
2363 Several zones in Antarctica and the former Soviet Union, along
2364 with zones intended for ships at sea that cannot use POSIX TZ
2365 strings, now use numeric time zone abbreviations instead of
2366 invented or obsolete alphanumeric abbreviations. The affected
2367 zones are Antarctica/Casey, Antarctica/Davis,
2368 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2369 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2370 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2371 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2372 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2373 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2374 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2375 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2376 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2377 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2378 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2379 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2380 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2381 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2382 was replaced by +05, whereas MSK and MSD were kept as they are not
2383 our invention and are widely used.
2385 Changes to zone names
2387 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2388 (Thanks to David Massoud.)
2392 zic no longer generates binary files containing POSIX TZ-like
2393 strings that disagree with the local time type after the last
2394 explicit transition in the data. This fixes a bug with
2395 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2396 on the reference platform. (Thanks to Alexander Belopolsky for
2397 reporting the bug and suggesting a way forward.)
2399 If the installed localtime and/or posixrules files are symbolic
2400 links, zic now keeps them symbolic links when updating them, for
2401 compatibility with platforms like OpenSUSE where other programs
2402 configure these files as symlinks.
2404 zic now avoids hard linking to symbolic links, avoids some
2405 unnecessary mkdir and stat system calls, and uses shorter file
2408 zdump has a new -i option to generate transitions in a
2409 smaller but still human-readable format. This option is
2410 experimental, and the output format may change in future versions.
2411 (Thanks to Jon Skeet for suggesting that an option was needed,
2412 and thanks to Tim Parenti and Chris Rovick for further comments.)
2414 Changes to build procedure
2416 An experimental distribution format is available, in addition
2417 to the traditional format which will continue to be distributed.
2418 The new format is a tarball tzdb-VERSION.tar.lz with signature
2419 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2420 tzdb-VERSION containing the code and data of the traditional
2421 two-tarball format, along with extra data that may be useful.
2422 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2423 for comments about the experimental format.)
2425 The release version number is now more accurate in the usual case
2426 where releases are built from a Git repository. For example, if
2427 23 commits and some working-file changes have been made since
2428 release 2016g, the version number is now something like
2429 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2430 Tagged releases use the same version number format as before,
2431 e.g., '2016g'. To support the more accurate version number, its
2432 specification has moved from a line in the Makefile to a new
2433 source file 'version'.
2435 The experimental distribution contains a file to2050.tzs that
2436 contains what should be the output of 'zdump -i -c 2050' on
2437 primary zones. If this file is available, 'make check' now checks
2438 that zdump generates this output.
2440 'make check_web' now works on Fedora-like distributions.
2442 Changes to documentation and commentary
2444 tzfile.5 now documents the new restriction on POSIX TZ-like
2445 strings that is now implemented by zic.
2447 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2448 (Thanks to Alexander Belopolsky.)
2450 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2451 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2452 description of Java 8 has been brought up to date (thanks to
2453 Stephen Colebourne). Its description of local time on Mars has
2454 been updated to match current practice, and URLs have been updated
2455 and some obsolete ones removed.
2458 Release 2016f - 2016-07-05 16:26:51 +0200
2460 Changes affecting future timestamps
2462 The Egyptian government changed its mind on short notice, and
2463 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2464 (Thanks to Mina Samuel.)
2466 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2467 (Thanks to Stepan Golosunov.)
2469 Changes to past and future timestamps
2471 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2472 abbreviations instead of invented ones.
2474 Changes affecting past timestamps
2476 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2477 (Thanks to Stepan Golosunov.)
2480 Release 2016e - 2016-06-14 08:46:16 -0700
2482 Changes affecting future timestamps
2484 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2485 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2486 For future years, guess April's last Thursday to October's last
2487 Thursday except for Ramadan.
2489 Changes affecting past timestamps
2491 Locations while uninhabited now use '-00', not 'zzz', as a
2492 placeholder time zone abbreviation. This is inspired by Internet
2493 RFC 3339 and is more consistent with numeric time zone
2494 abbreviations already used elsewhere. The change affects several
2495 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2496 1920 and Antarctica/Troll before 2005.
2498 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2499 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2503 zic now outputs a dummy transition at time 2**31 - 1 in zones
2504 whose POSIX-style TZ strings contain a '<'. This mostly works
2505 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2506 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2508 Changes affecting documentation and commentary
2510 tz-link.htm says why governments should give plenty of notice for
2511 time zone or DST changes, and refers to Matt Johnson's blog post.
2513 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2516 Release 2016d - 2016-04-17 22:50:29 -0700
2518 Changes affecting future timestamps
2520 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2521 (Thanks to Alexander Krivenyshev for the heads-up.)
2523 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2524 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2526 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2527 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2528 at 02:00. (Thanks to Stepan Golosunov.)
2530 Changes affecting past timestamps
2532 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2533 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2534 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2535 the same change. (Thanks to Stepan Golosunov.)
2537 Russia and nearby locations had daylight-saving transitions on
2538 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2539 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2542 Many corrections to historical time in Kazakhstan from 1991
2543 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2544 invented time zone abbreviations with numeric abbreviations.
2546 Changes to commentary
2548 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2551 Release 2016c - 2016-03-23 00:51:27 -0700
2553 Changes affecting future timestamps
2555 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2557 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2558 Correa for the heads-up, and to Tim Parenti for corrections.)
2559 Guess that future transitions are August's and May's second
2560 Saturdays at 24:00 mainland time. Also, call the period from
2561 2014-09-07 through 2016-05-14 daylight saving time instead of
2562 standard time, as that seems more appropriate now.
2564 Changes affecting past timestamps
2566 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2567 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2568 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2569 (Thanks to Stepan Golosunov.)
2571 Changes to commentary
2573 Several updates and URLs for historical and proposed Russian changes.
2574 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2577 Release 2016b - 2016-03-12 17:30:14 -0800
2581 Starting with release 2016b, some data entries cause zic implementations
2582 derived from tz releases 2005j through 2015e to issue warnings like
2583 "time zone abbreviation differs from POSIX standard (+03)".
2584 These warnings should not otherwise affect zic's output and can safely be
2585 ignored on today's platforms, as the warnings refer to a restriction in
2586 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2587 warnings is to upgrade to zic derived from tz releases 2015f and later.
2589 Changes affecting future timestamps
2591 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2592 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2593 2016-03-27 at 02:00 local time. They need distinct zones since their
2594 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2595 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2596 and local time. The Astrakhan change is already official; the others have
2597 passed the first reading in the State Duma and are extremely likely.
2598 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2599 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2600 and Stepan Golosunov for followup.)
2602 As a trial of a new system that needs less information to be made up,
2603 the new zones use numeric time zone abbreviations like "+04"
2604 instead of invented abbreviations like "ASTT".
2606 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2609 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2610 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2611 Saturday at 01:00, not March's last Friday at 24:00.
2613 Changes affecting past timestamps
2615 Europe/Chisinau observed DST during 1990, and switched from +04 to
2616 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2617 (Thanks to Stepan Golosunov.)
2619 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2620 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2624 tzselect's diagnostics and checking, and checktab.awk's checking,
2625 have been improved. (Thanks to J William Piggott.)
2627 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2629 tzselect now tests Julian-date TZ settings more accurately.
2630 (Thanks to J William Piggott.)
2632 Changes to commentary
2634 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2636 tzselect again limits its menu comments so that menus fit on a
2637 24×80 alphanumeric display.
2639 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2641 In the Theory file, the description of possible time zone abbreviations in
2642 tzdata has been cleaned up, as the old description was unclear and
2643 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2646 Release 2016a - 2016-01-26 23:28:02 -0800
2648 Changes affecting future timestamps
2650 America/Cayman will not observe daylight saving this year after all.
2651 Revert our guess that it would. (Thanks to Matt Johnson.)
2653 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2654 (Thanks to Alexander Krivenyshev.)
2656 Asia/Tehran now has DST predictions for the year 2038 and later,
2657 to be March 21 00:00 to September 21 00:00. This is likely better
2658 than predicting no DST, albeit off by a day every now and then.
2660 Changes affecting past and future timestamps
2662 America/Metlakatla switched from PST all year to AKST/AKDT on
2663 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2665 America/Santa_Isabel has been removed, and replaced with a
2666 backward compatibility link to America/Tijuana. Its contents were
2667 apparently based on a misreading of Mexican legislation.
2669 Changes affecting past timestamps
2671 Asia/Karachi's two transition times in 2002 were off by a minute.
2672 (Thanks to Matt Johnson.)
2674 Changes affecting build procedure
2676 An installer can now combine leap seconds with use of the backzone file,
2677 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2678 The old 'make posix_packrat' rule is now marked as obsolescent.
2679 (Thanks to Ian Abbott for an initial implementation.)
2681 Changes affecting documentation and commentary
2683 A new file LICENSE makes it easier to see that the code and data
2684 are mostly public-domain. (Thanks to James Knight.) The three
2685 non-public-domain files now use the current (3-clause) BSD license
2686 instead of older versions of that license.
2688 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2689 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2690 on editing tz source files (with a mention of Sublime zoneinfo,
2691 thanks to Gilmore Davidson).
2693 The Theory and asia files now mention the 2015 book "The Global
2694 Transformation of Time, 1870-1950", and cite a couple of reviews.
2696 The America/Chicago entry now documents the informal use of US
2697 central time in Fort Pierre, South Dakota. (Thanks to Rick
2698 McDermid, Matt Johnson, and Steve Jones.)
2701 Release 2015g - 2015-10-01 00:39:51 -0700
2703 Changes affecting future timestamps
2705 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2708 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2709 (Thanks to Alexander Krivenyshev.)
2711 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2712 (Thanks to Ken Rylander.)
2714 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2715 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2716 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2718 Changes affecting past timestamps
2720 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2722 Changes affecting code
2724 localtime no longer mishandles America/Anchorage after 2037.
2725 (Thanks to Bradley White for reporting the bug.)
2727 On hosts with signed 32-bit time_t, localtime no longer mishandles
2728 Pacific/Fiji after 2038-01-16 14:00 UTC.
2730 The localtime module allows the variables 'timezone', 'daylight',
2731 and 'altzone' to be in common storage shared with other modules,
2732 and declares them in case the system <time.h> does not.
2733 (Problems reported by Kees Dekker.)
2735 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2736 This simplifies the code and is consistent with zdump.c.
2737 (Problem reported by Christos Zoulas.)
2739 Changes affecting documentation
2741 The tzfile man page now documents that transition times denote the
2742 starts (not the ends) of the corresponding time periods.
2743 (Ambiguity reported by Bill Seymour.)
2746 Release 2015f - 2015-08-10 18:06:56 -0700
2748 Changes affecting future timestamps
2750 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2751 The abbreviation remains "KST". (Thanks to Robert Elz.)
2753 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2756 Changes affecting past and future timestamps
2758 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2759 (Thanks to Roman Tudos.)
2761 Changes affecting data format and code
2763 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2764 field of a Rule line should now be '-'; the old values 'even',
2765 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2766 Although the implementation has not changed, these features do not
2767 work in the default installation, they are not used in the data,
2768 and they are now considered obsolescent.
2770 zic now checks that two rules don't take effect at the same time.
2771 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2772 simultaneity are now documented.
2774 The two characters '%z' in a zone format now stand for the UT
2775 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2776 five hours and thirty minutes ahead. This better supports time
2777 zone abbreviations conforming to POSIX.1-2001 and later.
2779 Changes affecting installed data files
2781 Comments for America/Halifax and America/Glace_Bay have been improved.
2782 (Thanks to Brian Inglis.)
2784 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2785 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2786 installed data files for Europe/Simferopol and Europe/Tallinn.
2787 It does not affect timestamps. (Thanks to Howard Hinnant.)
2789 Changes affecting code
2791 zdump and zic no longer warn about valid time zone abbreviations
2794 Some Visual Studio 2013 warnings have been suppressed.
2795 (Thanks to Kees Dekker.)
2797 'date' no longer sets the time of day and its -a, -d, -n and -t
2798 options have been removed. Long obsolescent, the implementation
2799 of these features had porting problems. Builders no longer need
2800 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2801 (Thanks to Kees Dekker for pointing out the problem.)
2803 Changes affecting documentation
2805 The Theory file mentions naming issues earlier, as these seem to be
2806 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2808 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2810 Mention that Herbert Samuel introduced the term "Summer Time".
2813 Release 2015e - 2015-06-13 10:56:02 -0700
2815 Changes affecting future timestamps
2817 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2818 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2820 Assume Cayman Islands will observe DST starting next year, using US rules.
2821 Although it isn't guaranteed, it is the most likely.
2823 Changes affecting data format
2825 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2826 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2828 Changes affecting code
2830 When displaying data, tzselect converts it to the current locale's
2831 encoding if the iconv command works. (Problem reported by random832.)
2833 tzselect no longer mishandles Dominica, fixing a bug introduced
2834 in Release 2014f. (Problem reported by Owen Leibman.)
2836 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2837 This fixes a bug introduced in Release 2014f.
2838 (Problem reported by Leonardo Chiquitto.)
2841 Release 2015d - 2015-04-24 08:09:46 -0700
2843 Changes affecting future timestamps
2845 Egypt will not observe DST in 2015 and will consider canceling it
2846 permanently. For now, assume no DST indefinitely.
2847 (Thanks to Ahmed Nazmy and Tim Parenti.)
2849 Changes affecting past timestamps
2851 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2852 1966-07-01. Also, Yukon's time zone history is documented better.
2853 (Thanks to Brian Inglis and Dennis Ferguson.)
2855 Change affecting past and future time zone abbreviations
2857 The abbreviations for Hawaii-Aleutian standard and daylight times
2858 have been changed from HAST/HADT to HST/HDT, as per US Government
2859 Printing Office style. This affects only America/Adak since 1983,
2860 as America/Honolulu was already using the new style.
2862 Changes affecting code
2864 zic has some minor performance improvements.
2867 Release 2015c - 2015-04-11 08:55:55 -0700
2869 Changes affecting future timestamps
2871 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2872 not 00:00 on April's last Friday. 2015's transition will therefore be on
2873 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2874 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2876 Changes affecting past timestamps
2878 The following changes affect some pre-1991 Chile-related timestamps
2879 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2881 The 1910 transition was January 10, not January 1.
2883 The 1918 transition was September 10, not September 1.
2885 The UT -04 time observed from 1932 to 1942 is now considered to
2886 be standard time, not year-round DST.
2888 Santiago observed DST (UT -03) from 1946-07-15 through
2889 1946-08-31, then reverted to standard time, then switched to -05
2892 Assume transitions before 1968 were at 00:00, since we have no data
2895 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2896 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2898 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2899 and omit all transitions on Pacific/Easter from 1942 through 1946
2900 since we have no data suggesting that they existed.
2902 One more zone has been turned into a link, as it differed
2903 from an existing zone only for older timestamps. As usual,
2904 this change affects UT offsets in pre-1970 timestamps only.
2905 The zone's old contents have been moved to the 'backzone' file.
2906 The affected zone is America/Montreal.
2908 Changes affecting commentary
2910 Mention the TZUpdater tool.
2912 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2915 Release 2015b - 2015-03-19 23:28:11 -0700
2917 Changes affecting future timestamps
2919 Mongolia will start observing DST again this year, from the last
2920 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2921 (Thanks to Ganbold Tsagaankhuu.)
2923 Palestine will start DST on March 28, not March 27. Also,
2924 correct the fall 2014 transition from September 26 to October 24.
2925 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2927 Changes affecting past timestamps
2929 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2930 regression. (Thanks to Stuart Bishop for reporting the problem.)
2932 Some more zones have been turned into links, when they differed
2933 from existing zones only for older timestamps. As usual,
2934 these changes affect UT offsets in pre-1970 timestamps only.
2935 Their old contents have been moved to the 'backzone' file.
2936 The affected zones are: America/Antigua, America/Cayman,
2937 Pacific/Midway, and Pacific/Saipan.
2939 Changes affecting time zone abbreviations
2941 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2944 Changes affecting code
2946 Fix integer overflow bug in reference 'mktime' implementation.
2947 (Problem reported by Jörg Richter.)
2949 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2950 to be used in the same executable as standard-library time_t functions.
2951 (Problems reported by Bradley White.)
2953 Changes affecting commentary
2955 Cite the recent Mexican decree changing Quintana Roo's time zone.
2956 (Thanks to Carlos Raúl Perasso.)
2958 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2960 Update info about Mars time.
2963 Release 2015a - 2015-01-29 22:35:20 -0800
2965 Changes affecting future timestamps
2967 The Mexican state of Quintana Roo, represented by America/Cancun,
2968 will shift from Central Time with DST to Eastern Time without DST
2969 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2971 Chile will not change clocks in April or thereafter; its new standard time
2972 will be its old daylight saving time. This affects America/Santiago,
2973 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2975 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2976 (Thanks to Tim Parenti.)
2978 Changes affecting past timestamps
2980 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2981 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2982 Shanks about time in Iceland between 1837 and 1908.
2984 Some more zones have been turned into links, when they differed
2985 from existing zones only for older timestamps. As usual,
2986 these changes affect UT offsets in pre-1970 timestamps only.
2987 Their old contents have been moved to the 'backzone' file.
2988 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2991 Changes affecting code
2993 tzalloc now scrubs time zone abbreviations compatibly with the way
2994 that tzset always has, by replacing invalid bytes with '_' and by
2995 shortening too-long abbreviations.
2997 tzselect ports to POSIX awk implementations, no longer mishandles
2998 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2999 settings to the user. (Thanks to Stefan Kuhn.)
3001 Changes affecting build procedure
3003 'make check' now checks for links to links in the data.
3004 One such link (for Africa/Asmera) has been fixed.
3005 (Thanks to Stephen Colebourne for pointing out the problem.)
3007 Changes affecting commentary
3009 The leapseconds file commentary now mentions the expiration date.
3010 (Problem reported by Martin Burnicki.)
3012 Update Mexican Library of Congress URL.
3015 Release 2014j - 2014-11-10 17:37:11 -0800
3017 Changes affecting current and future timestamps
3019 Turks & Caicos' switch from US eastern time to UT -04 year-round
3020 did not occur on 2014-11-02 at 02:00. It's currently scheduled
3021 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
3023 Changes affecting past timestamps
3025 Many pre-1989 timestamps have been corrected for Asia/Seoul and
3026 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
3027 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
3028 longer guess that Pyongyang mimicked Seoul time after World War II,
3029 as this is politically implausible.
3031 Some more zones have been turned into links, when they differed
3032 from existing zones only for older timestamps. As usual,
3033 these changes affect UT offsets in pre-1970 timestamps only.
3034 Their old contents have been moved to the 'backzone' file.
3035 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
3036 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
3037 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
3040 Changes affecting commentary
3042 The commentary is less enthusiastic about Shanks as a source,
3043 and is more careful to distinguish UT from UTC.
3046 Release 2014i - 2014-10-21 22:04:57 -0700
3048 Changes affecting future timestamps
3050 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
3051 (Thanks to Ken Rylander for the heads-up.) Guess that future
3052 years will use a similar pattern.
3054 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
3055 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
3056 (Thanks to Kiley Walbom for the heads-up.)
3058 Changes affecting time zone abbreviations
3060 Since Belarus is not changing its clocks even though Moscow is,
3061 the time zone abbreviation in Europe/Minsk is changing from FET
3062 to its more traditional value MSK on 2014-10-26 at 01:00.
3063 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
3065 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
3066 Indochina, to distinguish it better from ICT (+07).
3068 Changes affecting past timestamps
3070 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
3071 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
3072 authoritative book). Asia/Ho_Chi_Minh has been added to
3073 zone1970.tab, to give tzselect users in Vietnam two choices,
3074 since north and south Vietnam disagreed after our 1970 cutoff.
3076 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
3077 they differed from existing zones only for older timestamps. As
3078 usual, these changes affect pre-1970 timestamps only. Their old
3079 contents have been moved to the 'backzone' file.
3081 Changes affecting code
3083 The time-related library functions now set errno on failure, and
3084 some crashes in the new tzalloc-related library functions have
3085 been fixed. (Thanks to Christos Zoulas for reporting most of
3086 these problems and for suggesting fixes.)
3088 If USG_COMPAT is defined and the requested timestamp is standard time,
3089 the tz library's localtime and mktime functions now set the extern
3090 variable timezone to a value appropriate for that timestamp; and
3091 similarly for ALTZONE, daylight saving time, and the altzone variable.
3092 This change is a companion to the tzname change in 2014h, and is
3093 designed to make timezone and altzone more compatible with tzname.
3095 The tz library's functions now set errno to EOVERFLOW if they fail
3096 because the result cannot be represented. ctime and ctime_r now
3097 return NULL and set errno when a timestamp is out of range, rather
3098 than having undefined behavior.
3100 Some bugs associated with the new 2014g functions have been fixed.
3101 This includes a bug that largely incapacitated the new functions
3102 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
3103 It also includes some uses of uninitialized variables after tzalloc.
3104 The new code uses the standard type 'ssize_t', which the Makefile
3105 now gives porting advice about.
3107 Changes affecting commentary
3109 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
3112 Release 2014h - 2014-09-25 18:59:03 -0700
3114 Changes affecting past timestamps
3116 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
3118 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
3119 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
3121 Some more zones have been turned into links, when they differed
3122 from existing zones only for older timestamps. As usual,
3123 these changes affect UT offsets in pre-1970 timestamps only.
3124 Their old contents have been moved to the 'backzone' file.
3125 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
3126 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
3127 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
3129 Changes affecting code
3131 zdump -V and -v now output gmtoff= values on all platforms,
3132 not merely on platforms defining TM_GMTOFF.
3134 The tz library's localtime and mktime functions now set tzname to a value
3135 appropriate for the requested timestamp, and zdump now uses this
3136 on platforms not defining TM_ZONE, fixing a 2014g regression.
3137 (Thanks to Tim Parenti for reporting the problem.)
3139 The tz library no longer sets tzname if localtime or mktime fails.
3141 zdump -c no longer mishandles transitions near year boundaries.
3142 (Thanks to Tim Parenti for reporting the problem.)
3144 An access to uninitialized data has been fixed.
3145 (Thanks to Jörg Richter for reporting the problem.)
3147 When THREAD_SAFE is defined, the code ports to the C11 memory model.
3148 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
3149 and two threads race to initialize data used by gmtime-like functions.
3150 (Thanks to Andy Heninger for reporting the problems.)
3152 Changes affecting build procedure
3154 'make check' now checks better for properly sorted data.
3156 Changes affecting documentation and commentary
3158 zdump's gmtoff=N output is now documented, and its isdst=D output
3159 is now documented to possibly output D values other than 0 or 1.
3161 zdump -c's treatment of years is now documented to use the
3162 Gregorian calendar and Universal Time without leap seconds,
3163 and its behavior at cutoff boundaries is now documented better.
3164 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
3166 Programs are now documented to use the proleptic Gregorian calendar.
3167 (Thanks to Alan Barrett for the suggestion.)
3169 Fractional-second GMT offsets have been documented for civil time
3170 in 19th-century Chennai, Jakarta, and New York.
3173 Release 2014g - 2014-08-28 12:31:23 -0700
3175 Changes affecting future timestamps
3177 Turks & Caicos is switching from US eastern time to UT -04
3178 year-round, modeled as a switch on 2014-11-02 at 02:00.
3179 [As noted in 2014j, this switch was later delayed.]
3181 Changes affecting past timestamps
3183 Time in Russia or the USSR before 1926 or so has been corrected by
3184 a few seconds in the following zones: Asia/Irkutsk,
3185 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
3186 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
3187 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
3188 Vladimir Karpinsky.)
3190 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
3191 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
3192 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
3193 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
3194 (Thanks to Stephen Colebourne for pointing to the decree.)
3196 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
3198 A new file 'backzone' contains data which may appeal to
3199 connoisseurs of old timestamps, although it is out of scope for
3200 the tz database, is often poorly sourced, and contains some data
3201 that is known to be incorrect. The new file is not recommended
3202 for ordinary use and its entries are not installed by default.
3203 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
3204 Isle of Man entries.)
3206 Some more zones have been turned into links, when they differed
3207 from existing zones only for older timestamps. As usual,
3208 these changes affect UT offsets in pre-1970 timestamps only.
3209 Their old contents have been moved to the 'backzone' file.
3210 The affected zones are: Africa/Bangui, Africa/Brazzaville,
3211 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
3212 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
3214 Changes affecting code
3216 Unless NETBSD_INSPIRED is defined to 0, the tz library now
3217 supplies functions for creating and using objects that represent
3218 timezones. The new functions are tzalloc, tzfree, localtime_rz,
3219 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
3220 time2posix_z. They are intended for performance: for example,
3221 localtime_rz (unlike localtime_r) is trivially thread-safe without
3222 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
3223 functions, and to Alan Barrett and Jonathan Lennox for helping to
3226 zdump now builds with the tz library unless USE_LTZ is defined to 0,
3227 This lets zdump use tz features even if the system library lacks them.
3228 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
3229 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
3231 zdump now uses localtime_rz if available, as it's significantly faster,
3232 and it can help zdump better diagnose invalid timezone names.
3233 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
3234 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
3235 not available, zdump now uses localtime_r and tzset if available,
3236 as this is a bit cleaner and faster than plain localtime. Compile
3237 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
3238 lacks these two functions.
3240 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
3241 Although not needed for tz's own applications, which are single-threaded,
3242 this supports POSIX better if the tz library is used in multithreaded apps.
3244 Some crashes have been fixed when zdump or the tz library is given
3245 invalid or outlandish input.
3247 The tz library no longer mishandles leap seconds on platforms with
3248 unsigned time_t in timezones that lack ordinary transitions after 1970.
3250 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
3251 already defined, to make it easier to configure on common platforms.
3252 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
3254 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
3255 assumes that reading uninitialized memory yields garbage values
3256 but does not cause other problems such as traps.
3258 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
3259 more likely to guess right for ambiguous timestamps near
3260 transitions where tm_isdst does not change.
3262 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
3263 strftime_l for compatibility with recent versions of POSIX.
3264 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
3265 to 1 on recent POSIX versions, and to 0 otherwise.
3267 tzselect -c now uses a hybrid distance measure that works better
3268 in Africa. (Thanks to Alan Barrett for noting the problem.)
3270 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
3271 or when time_tz is defined.
3273 When HAVE_UTMPX_H is set the 'date' command now builds on systems
3274 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
3275 the date it updates the wtmpx file if _PATH_WTMPX is defined.
3276 This affects GNU/Linux and similar systems.
3278 For easier maintenance later, some C code has been simplified,
3279 some lint has been removed, and the code has been tweaked so that
3280 plain 'make' is more likely to work.
3282 The C type 'bool' is now used for boolean values, instead of 'int'.
3284 The long-obsolete LOCALE_HOME code has been removed.
3286 The long-obsolete 'gtime' function has been removed.
3288 Changes affecting build procedure
3290 'zdump' no longer links in ialloc.o, as it's not needed.
3292 'make check_time_t_alternatives' no longer assumes GNU diff.
3294 Changes affecting distribution tarballs
3296 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
3297 the tzdata tarball instead of the tzcode tarball, since they help
3298 maintain the data. The NEWS and Theory files are now also
3299 distributed in the tzdata tarball, as they're relevant for data.
3300 (Thanks to Alan Barrett for pointing this out.) Also, the
3301 leapseconds.awk file is no longer distributed in the tzcode
3302 tarball, since it belongs in the tzdata tarball (where 2014f
3303 inadvertently also distributed it).
3305 Changes affecting documentation and commentary
3307 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
3308 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
3311 The man pages have been updated to use function prototypes,
3312 to document thread-safe variants like localtime_r, and to document
3313 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
3316 The fields in Link lines have been renamed to be more descriptive
3317 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
3318 and LINK-TO has become LINK-NAME.
3320 tz-link.htm mentions the IETF's tzdist working group; Windows
3321 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
3323 Some broken URLs have been fixed in the commentary. (Thanks to
3326 Commentary about Philippines DST has been updated, and commentary
3327 on pre-1970 time in India has been added.
3330 Release 2014f - 2014-08-05 17:42:36 -0700
3332 Changes affecting future timestamps
3334 Russia will subtract an hour from most of its time zones on 2014-10-26
3335 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
3336 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
3337 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
3338 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
3339 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
3340 (Europe/Samara) are not changing their clocks. The changed zones are
3341 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
3342 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
3343 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
3344 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
3345 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
3346 but not its UTC offset. Two zones are added: Asia/Chita (split
3347 from Asia/Yakutsk, and also with two hours subtracted) and
3348 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
3349 subtracted). (Thanks to Tim Parenti for much of the above.)
3351 Changes affecting time zone abbreviations
3353 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3354 and similarly for the other Australian zones. That is, for eastern
3355 standard and daylight saving time the abbreviations are AEST and AEDT
3356 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3357 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3358 This change does not affect UT offsets, only time zone abbreviations.
3359 (Thanks to Rich Tibbett and many others.)
3361 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3362 effective 2014-10-26 at 02:00 local time.
3364 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3365 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3367 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3368 Similarly, prefer EET/EEST for eastern European time in Russia.
3370 Change time zone abbreviations in (western) Samoa to use "ST" and
3371 "DT" suffixes, as this is more likely to match common practice.
3372 Prefix "W" to (western) Samoa time when its standard-time offset
3373 disagrees with that of American Samoa.
3375 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3377 Time zone abbreviations have been updated for Japan's two time
3378 zones used 1896-1937. JWST now stands for Western Standard
3379 Time, and JCST for Central Standard Time (formerly this was CJT).
3380 These abbreviations are now used for time in Korea, Taiwan,
3381 and Sakhalin while controlled by Japan.
3383 Changes affecting past timestamps
3385 China's five zones have been simplified to two, since the post-1970
3386 differences in the other three seem to have been imaginary. The
3387 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3388 removed; backwards-compatibility links still work, albeit with
3389 different behaviors for timestamps before May 1980. Asia/Urumqi's
3390 1980 transition to UT +08 has been removed, so that it is now at
3391 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3392 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3394 Some zones have been turned into links, when they differed from existing
3395 zones only for older UT offsets where data entries were likely invented.
3396 These changes affect UT offsets in pre-1970 timestamps only. This is
3397 similar to the change in release 2013e, except this time for western
3398 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3399 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3400 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3401 Atlantic/St_Helena. This also affects the backwards-compatibility
3402 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3403 Tim Parenti, and David Patte for reporting problems in earlier
3404 versions of this change.)
3406 Asia/Shanghai's pre-standard-time UT offset has been changed from
3407 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3408 transition to standard time has been changed from 1928 to 1901.
3410 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3411 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3412 In 1946 it observed DST from 05-15 through 09-30; in 1947
3413 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3414 (Thanks to Yu-Cheng Chuang.)
3416 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3418 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3419 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3421 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3422 period from 1911 to 1950.
3424 Pacific/Chatham has been changed to New Zealand standard time plus
3425 45 minutes for the period before 1957, reflecting a 1956 remark in
3426 the New Zealand parliament.
3428 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3429 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3430 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3431 not 04-06 at 02:00; and there was no DST in 1920.
3433 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3435 Time in Russia before 1927 or so has been corrected by a few seconds in
3436 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3437 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3438 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3439 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3441 Changes affecting data format
3443 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3444 The new file's extended format allows multiple country codes per zone.
3445 The older file is still installed but is deprecated; its format is
3446 not changing and it will still be distributed for a while, but new
3447 applications should use the new file.
3449 The new file format simplifies maintenance of obscure locations.
3450 To test this, it adds coverage for the Crozet Islands and the
3451 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3453 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3454 It is still ASCII now, but commentary about the switch has been added.
3455 The new file 'zone1970.tab' already uses UTF-8.
3457 Changes affecting code
3459 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3460 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3462 'zic' no longer mishandles input when ignoring case in locales that
3463 are not compatible with English, e.g., unibyte Turkish locales when
3464 compiled with HAVE_GETTEXT.
3466 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3467 they no longer use ASCII '-' as if it were a dash.
3469 'zic' now rejects output file names that contain '.' or '..' components.
3470 (Thanks to Tim Parenti for reporting the problem.)
3472 'zic -v' now warns about output file names that do not follow
3473 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3474 David Olson for starting the ball rolling on this.)
3476 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3478 Changes affecting build procedure
3480 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3481 (Thanks to John Cochran.)
3483 Changes affecting documentation and commentary
3485 The 'Theory' file documents legacy names, the longstanding
3486 exceptions to the POSIX-inspired file name rules.
3488 The 'zic' documentation clarifies the role of time types when
3489 interpreting dates. (Thanks to Arthur David Olson.)
3491 Documentation and commentary now prefer UTF-8 to US-ASCII,
3492 allowing the use of proper accents in foreign words and names.
3493 Code and data have not changed because of this. (Thanks to
3494 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3497 Non-HTML documentation and commentary now use plain-text URLs instead of
3498 HTML insertions, and are more consistent about bracketing URLs when they
3499 are not already surrounded by white space. (Thanks to suggestions by
3502 There is new commentary about Xujiahui Observatory, the five time-zone
3503 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3504 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3505 warlord Jin Shuren in the data.
3507 Commentary about the coverage of each Russian zone has been standardized.
3508 (Thanks to Tim Parenti.)
3510 There is new commentary about contemporary timekeeping in Ethiopia.
3512 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3514 There is new commentary about time in Poland in 1919.
3516 Proper credit has been given to DST inventor George Vernon Hudson.
3518 Commentary about time in Metlakatla, AK and Resolute, NU has been
3519 improved, with a new source for the former.
3521 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3524 Commentary about permanent Antarctic bases has been updated.
3526 Several typos have been corrected. (Thanks to Tim Parenti for
3527 contributing some of these fixes.)
3529 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3530 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3531 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3532 (Thanks to a heads-up from Dirkjan Ochtman.)
3534 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3535 have been removed. These obsolescent US Naval Observatory entries were no
3536 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3539 Release 2014e - 2014-06-12 21:53:52 -0700
3541 Changes affecting near-future timestamps
3543 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3544 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3545 switch to standard time at 24:00 the last Thursday before Ramadan, and
3546 back to DST at 00:00 the first Friday after Ramadan.
3548 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3549 to Milamber Space Network.) Guess that from 2015 on Morocco will
3550 temporarily switch to standard time at 03:00 the last Saturday before
3551 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3553 Changes affecting past timestamps
3555 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3556 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3557 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3558 in 1991. (Thanks to Hank W. for reporting the problems.)
3560 Changes affecting commentary
3562 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3563 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3564 removes stale pointers to World Time Explorer and WORLDTIME.
3567 Release 2014d - 2014-05-27 21:34:40 -0700
3569 Changes affecting code
3571 zic no longer generates files containing timestamps before the Big Bang.
3572 This works around GNOME glib bug 878
3573 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3574 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3575 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3577 Changes affecting documentation
3579 tz-link.htm now mentions GNOME.
3582 Release 2014c - 2014-05-13 07:44:13 -0700
3584 Changes affecting near-future timestamps
3586 Egypt observes DST starting 2014-05-15 at 24:00.
3587 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3588 Details have not been announced, except that DST will not be observed
3589 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3590 Morocco, and that Egypt's future spring and fall transitions will be the
3591 same as 2010 when it last observed DST, namely April's last Friday at
3592 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3593 that Ramadan transitions will be at 00:00 standard time.
3595 Changes affecting code
3597 zic now generates transitions for minimum time values, eliminating guesswork
3598 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3600 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3602 Changes affecting commentary and documentation
3604 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3607 Release 2014b - 2014-03-24 21:28:50 -0700
3609 Changes affecting near-future timestamps
3611 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3612 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3614 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3615 Bengt-Inge Larsson.) This is currently an approximation; a better version
3616 will require the zic and localtime fixes mentioned below, and the plan is
3617 to wait for a while until at least the zic fixes propagate.
3619 Changes affecting code
3621 'zic' and 'localtime' no longer reject locations needing four transitions
3622 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3623 Also, 'zic' avoids some unlikely failures due to integer overflow.
3625 Changes affecting build procedure
3627 'make check' now detects Rule lines defined but never used.
3628 The NZAQ rules, an instance of this problem, have been removed.
3630 Changes affecting commentary and documentation
3632 Fix Tuesday/Thursday typo in description of time in Israel.
3633 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3635 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3636 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3637 library supports them.
3639 Add comments about Johnston Island time in the 1960s.
3640 (Thanks to Lyle McElhaney.)
3642 Morocco's 2014 DST start will be as predicted.
3643 (Thanks to Sebastien Willemijns.)
3646 Release 2014a - 2014-03-07 23:30:29 -0800
3648 Changes affecting near-future timestamps
3650 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3651 the heads-up, and to Tim Parenti for simplifying the update.)
3653 Changes affecting past timestamps
3655 Fiji ended DST on 2014-01-19 at 02:00, not the previously scheduled 03:00.
3656 (Thanks to Steffen Thorsen.)
3658 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3659 (not 1992-01-01), and observed DST during the entire next winter.
3660 (Thanks to Vladimir in Moscow via Alois Treindl.)
3662 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3663 (Thanks to Avigdor Finkelstein.)
3665 Changes affecting code
3667 A uninitialized-storage bug in 'localtime' has been fixed.
3668 (Thanks to Logan Chien.)
3670 Changes affecting the build procedure
3672 The settings for 'make check_web' now default to Ubuntu 13.10.
3674 Changes affecting commentary and documentation
3676 The boundary of the US Pacific time zone is given more accurately.
3677 (Thanks to Alan Mintz.)
3679 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3681 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3683 Better descriptions of countries with same time zone history as
3684 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3686 Several changes affect tz-link.htm, the main web page.
3688 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3691 Mention xCal (Internet RFC 6321) and jCal.
3693 Microsoft has some support for tz database names.
3695 CLDR data formats include both XML and JSON.
3697 Mention Maggiolo's map of solar vs standard time.
3698 (Thanks to Arthur David Olson.)
3700 Mention TZ4Net. (Thanks to Matt Johnson.)
3702 Mention the timezone-olson Haskell package.
3704 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3706 Remove moribund links to daylight-savings-time.info and to
3707 Simple Timer + Clocks.
3709 Update two links. (Thanks to Oscar van Vlijmen.)
3711 Fix some formatting glitches, e.g., remove random newlines from
3712 abbr elements' title attributes.
3715 Release 2013i - 2013-12-17 07:25:23 -0800
3717 Changes affecting near-future timestamps:
3719 Jordan switches back to standard time at 00:00 on December 20, 2013.
3720 The 2006-2011 transition schedule is planned to resume in 2014.
3721 (Thanks to Steffen Thorsen.)
3723 Changes affecting past timestamps:
3725 In 2004, Cuba began DST on March 28, not April 4.
3726 (Thanks to Steffen Thorsen.)
3728 Changes affecting code
3730 The compile-time flag NOSOLAR has been removed, as nowadays the
3731 benefit of slightly shrinking runtime table size is outweighed by the
3732 cost of disallowing potential future updates that exceed old limits.
3734 Changes affecting documentation and commentary
3736 The files solar87, solar88, and solar89 are no longer distributed.
3737 They were a negative experiment - that is, a demonstration that
3738 tz data can represent solar time only with some difficulty and error.
3739 Their presence in the distribution caused confusion, as Riyadh
3740 civil time was generally not solar time in those years.
3742 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3745 Release 2013h - 2013-10-25 15:32:32 -0700
3747 Changes affecting current and future timestamps:
3749 Libya has switched its UT offset back to +02 without DST, instead
3750 of +01 with DST. (Thanks to Even Scharning.)
3752 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3753 (Thanks to Gwillim Law.)
3755 Changes affecting future timestamps:
3757 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3758 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3759 (Thanks to Steffen Thorsen.)
3761 Add entries for DST transitions in Morocco in the year 2038.
3762 This avoids some year-2038 glitches introduced in 2013g.
3763 (Thanks to Yoshito Umaoka for reporting the problem.)
3765 Changes affecting API
3767 The 'tzselect' command no longer requires the 'select' command,
3768 and should now work with /bin/sh on more platforms. It also works
3769 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3770 Patrick 'P. J.' McDermott and Alan Barrett.)
3772 Changes affecting code
3774 Fix localtime overflow bugs with 32-bit unsigned time_t.
3776 zdump no longer assumes sscanf returns maximal values on overflow.
3778 Changes affecting the build procedure
3780 The builder can specify which programs to use, if any, instead of
3781 'ar' and 'ranlib', and libtz.a is now built locally before being
3782 installed. (Thanks to Michael Forney.)
3784 A dependency typo in the 'zdump' rule has been fixed.
3785 (Thanks to Andrew Paprocki.)
3787 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3788 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3790 'make clean' no longer removes 'leapseconds', since it's
3791 host-independent and is part of the distribution.
3793 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3795 Changes affecting documentation and commentary
3797 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3798 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3800 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3801 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3802 longer maintained) and for old advisories. SOFA now does C.
3804 Release 2013g - 2013-09-30 21:08:26 -0700
3806 Changes affecting current and near-future timestamps
3808 Morocco now observes DST from the last Sunday in March to the last
3809 Sunday in October, not April to September respectively. (Thanks
3810 to Steffen Thorsen.)
3812 Changes affecting 'zic'
3814 'zic' now runs on platforms that lack both hard links and symlinks.
3815 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3816 Also, fix some bugs on platforms that lack hard links but have symlinks.
3818 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3819 to predict the far future, fixing a bug introduced in 2013e.
3821 Changes affecting the build procedure
3823 The 'leapseconds' file is again put into the tzdata tarball.
3824 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3825 Matt Burgess and Ian Abbott.) The timestamps of these and other
3826 dependent files in tarballs are adjusted more consistently.
3828 Changes affecting documentation and commentary
3830 The README file is now part of the data tarball as well as the code.
3831 It now states that files are public domain unless otherwise specified.
3832 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3833 Its details about the 1989 release moved to a place of honor near
3837 Release 2013f - 2013-09-24 23:37:36 -0700
3839 Changes affecting near-future timestamps
3841 Tocantins will very likely not observe DST starting this spring.
3842 (Thanks to Steffen Thorsen.)
3844 Jordan will likely stay at UT +03 indefinitely, and will not fall
3847 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3849 Changes affecting API
3851 The types of the global variables 'timezone' and 'altzone' (if present)
3852 have been changed back to 'long'. This is required for 'timezone'
3853 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3854 These variables were originally 'long' in the tz code, but were
3855 mistakenly changed to 'time_t' in 1987; nobody reported the
3856 incompatibility until now. The difference matters on x32, where
3857 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3859 Changes affecting the build procedure
3861 Avoid long strings in leapseconds.awk to work around a mawk bug.
3862 (Thanks to Cyril Baurand.)
3864 Changes affecting documentation and commentary
3866 New file 'NEWS' that contains release notes like this one.
3868 Paraguay's law does not specify DST transition time; 00:00 is customary.
3869 (Thanks to Waldemar Villamayor-Venialbo.)
3871 Minor capitalization fixes.
3873 Changes affecting version-control only
3875 The experimental GitHub repository now contains annotated and
3876 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3877 Releases are tagged starting with 2012e; earlier releases were
3878 done differently, and tags would either not have a simple name or
3879 not exactly match what was released.
3881 'make set-timestamps' is now simpler and a bit more portable.
3884 Release 2013e - 2013-09-19 23:50:04 -0700
3886 Changes affecting near-future timestamps
3888 This year Fiji will start DST on October 27, not October 20.
3889 (Thanks to David Wheeler for the heads-up.) For now, guess that
3890 Fiji will continue to spring forward the Sunday before the fourth
3893 Changes affecting current and future time zone abbreviations
3895 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3896 time zone abbreviations since 1932. (Thanks to George Ziegler,
3897 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3898 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3899 Asia/Makassar, and Asia/Pontianak.
3901 Use ART (UT -03, standard time), rather than WARST (also -03, but
3902 daylight saving time) for San Luis, Argentina since 2009.
3904 Changes affecting Godthåb timestamps after 2037 if version mismatch
3906 Allow POSIX-like TZ strings where the transition time's hour can
3907 range from -167 through 167, instead of the POSIX-required 0
3908 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3909 new Fiji rules. This is a more compact way to represent
3910 far-future timestamps for America/Godthab, America/Santiago,
3911 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3912 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3913 this change. (Derived from a suggestion by Arthur David Olson.)
3915 Allow POSIX-like TZ strings where daylight saving time is in
3916 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3917 Argentina Summer Time all year. This supports a more compact way
3918 to represent the 2013d data for America/Argentina/San_Luis.
3919 Because of the change for San Luis noted above this change does not
3920 affect the current data. (Thanks to Andrew Main (Zefram) for
3921 suggestions that improved this change.)
3923 Where these two TZ changes take effect, there is a minor extension
3924 to the tz file format in that it allows new values for the
3925 embedded TZ-format string, and the tz file format version number
3926 has therefore been increased from 2 to 3 as a precaution.
3927 Version-2-based client code should continue to work as before for
3928 all timestamps before 2038. Existing version-2-based client code
3929 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3930 files, and typically works in practice even for timestamps after
3931 2037; the only known exception is America/Godthab.
3933 Changes affecting timestamps before 1970
3935 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3936 some errors before 1947.
3938 Some zones have been turned into links, when they differ from existing
3939 zones only in older data entries that were likely invented or that
3940 differ only in LMT or transitions from LMT. These changes affect
3941 only timestamps before 1943. The affected zones are:
3942 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3943 America/Grenada, America/Guadeloupe, America/Marigot,
3944 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3945 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3946 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3947 confirming that the old Europe/Vaduz zone was wrong and the new
3948 link is better for WWII-era times.)
3950 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3951 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3954 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3955 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3958 Change the date of the circa-1850 Zurich transition from 1849-09-12
3959 to 1853-07-16, overriding Shanks with data from Messerli about
3960 postal and telegraph time in Switzerland.
3962 Changes affecting time zone abbreviations before 1970
3964 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3965 as Jakarta was called Batavia back then.
3967 Changes affecting API
3969 The 'zic' command now outputs a dummy transition when far-future
3970 data can't be summarized using a TZ string, and uses a 402-year
3971 window rather than a 400-year window. For the current data, this
3972 affects only the Asia/Tehran file. It does not affect any of the
3973 timestamps that this file represents, so zdump outputs the same
3974 information as before. (Thanks to Andrew Main (Zefram).)
3976 The 'date' command has a new '-r' option, which lets you specify
3977 the integer time to display, a la FreeBSD.
3979 The 'tzselect' command has two new options '-c' and '-n', which lets you
3980 select a zone based on latitude and longitude.
3982 The 'zic' command's '-v' option now warns about constructs that
3983 require the new version-3 binary file format. (Thanks to Arthur
3984 David Olson for the suggestion.)
3986 Support for floating-point time_t has been removed.
3987 It was always dicey, and POSIX no longer requires it.
3988 (Thanks to Eric Blake for suggesting to the POSIX committee to
3989 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3990 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3991 bugs and elucidating some of the corners of the old floating-point
3994 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3995 changed back to the old practice of using 'long' to represent UT
3996 offsets. This had been inadvertently and mistakenly changed to
3997 'int_fast32_t'. (Thanks to Christos Zoulas.)
3999 The code avoids undefined behavior on integer overflow in some
4000 more places, including gmtime, localtime, mktime and zdump.
4002 Changes affecting the zdump utility
4004 zdump now outputs "UT" when referring to Universal Time, not "UTC".
4005 "UTC" does not make sense for timestamps that predate the introduction
4006 of UTC, whereas "UT", a more generic term, does. (Thanks to Steve Allen
4007 for clarifying UT vs UTC.)
4009 Data changes affecting behavior of tzselect and similar programs
4011 Country code BQ is now called the more common name "Caribbean Netherlands"
4012 rather than the more official "Bonaire, St Eustatius & Saba".
4014 Remove from zone.tab the names America/Montreal, America/Shiprock,
4015 and Antarctica/South_Pole, as they are equivalent to existing
4016 same-country-code zones for post-1970 timestamps. The data entries for
4017 these names are unchanged, so the names continue to work as before.
4019 Changes affecting code internals
4021 zic -c now runs way faster on 64-bit hosts when given large numbers.
4023 zic now uses vfprintf to avoid allocating and freeing some memory.
4025 tzselect now computes the list of continents from the data,
4026 rather than have it hard-coded.
4028 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
4030 Changes affecting the build procedure
4032 The 'leapseconds' file is now generated automatically from a
4033 new file 'leap-seconds.list', which is a copy of
4034 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
4035 A new source file 'leapseconds.awk' implements this.
4036 The goal is simplification of the future maintenance of 'leapseconds'.
4038 When building the 'posix' or 'right' subdirectories, if the
4039 subdirectory would be a copy of the default subdirectory, it is
4040 now made a symbolic link if that is supported. This saves about
4041 2 MB of file system space.
4043 The links America/Shiprock and Antarctica/South_Pole have been
4044 moved to the 'backward' file. This affects only nondefault builds
4045 that omit 'backward'.
4047 Changes affecting version-control only
4049 .gitignore now ignores 'date'.
4051 Changes affecting documentation and commentary
4053 Changes to the 'tzfile' man page
4055 It now mentions that the binary file format may be extended in
4056 future versions by appending data.
4058 It now refers to the 'zdump' and 'zic' man pages.
4060 Changes to the 'zic' man page
4062 It lists conditions that elicit a warning with '-v'.
4064 It says that the behavior is unspecified when duplicate names
4065 are given, or if the source of one link is the target of another.
4067 Its examples are updated to match the latest data.
4069 The definition of white space has been clarified slightly.
4070 (Thanks to Michael Deckers.)
4072 Changes to the 'Theory' file
4074 There is a new section about the accuracy of the tz database,
4075 describing the many ways that errors can creep in, and
4076 explaining why so many of the pre-1970 timestamps are wrong or
4077 misleading (thanks to Steve Allen, Lester Caine, and Garrett
4078 Wollman for discussions that contributed to this).
4080 The 'Theory' file describes LMT better (this follows a
4081 suggestion by Guy Harris).
4083 It refers to the 2013 edition of POSIX rather than the 2004 edition.
4085 It's mentioned that excluding 'backward' should not affect the
4086 other data, and it suggests at least one zone.tab name per
4087 inhabited country (thanks to Stephen Colebourne).
4089 Some longstanding restrictions on names are documented, e.g.,
4090 'America/New_York' precludes 'America/New_York/Bronx'.
4092 It gives more reasons for the 1970 cutoff.
4094 It now mentions which time_t variants are supported, such as
4095 signed integer time_t. (Thanks to Paul Goyette for reporting
4096 typos in an experimental version of this change.)
4098 (Thanks to Philip Newton for correcting typos in these changes.)
4100 Documentation and commentary is more careful to distinguish UT in
4101 general from UTC in particular. (Thanks to Steve Allen.)
4103 Add a better source for the Zurich 1894 transition.
4104 (Thanks to Pierre-Yves Berger.)
4106 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
4109 Release 2013d - 2013-07-05 07:38:01 -0700
4111 Changes affecting future timestamps:
4113 Morocco's midsummer transitions this year are July 7 and August 10,
4114 not July 9 and August 8. (Thanks to Andrew Paprocki.)
4116 Israel now falls back on the last Sunday of October.
4117 (Thanks to Ephraim Silverberg.)
4119 Changes affecting past timestamps:
4121 Specify Jerusalem's location more precisely; this changes the pre-1880
4124 Changing affecting metadata only:
4126 Fix typos in the entries for country codes BQ and SX.
4128 Changes affecting code:
4130 Rework the code to fix a bug with handling Australia/Macquarie on
4131 32-bit hosts (thanks to Arthur David Olson).
4133 Port to platforms like NetBSD, where time_t can be wider than long.
4135 Add support for testing time_t types other than the system's.
4136 Run 'make check_time_t_alternatives' to try this out.
4137 Currently, the tests fail for unsigned time_t;
4138 this should get fixed at some point.
4140 Changes affecting documentation and commentary:
4142 Deemphasize the significance of national borders.
4144 Update the zdump man page.
4146 Remove obsolete NOID comment (thanks to Denis Excoffier).
4148 Update several URLs and comments in the web pages.
4150 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
4152 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
4155 Release 2013c - 2013-04-19 16:17:40 -0700
4157 Changes affecting current and future timestamps:
4159 Palestine observed DST starting March 29, 2013. (Thanks to
4160 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
4161 with the predicted rules being the last Thursday in March at 24:00
4162 to the first Friday on or after September 21 at 01:00.
4164 Assume that the recent change to Paraguay's DST rules is permanent,
4165 by moving the end of DST to the 4th Sunday in March every year.
4166 (Thanks to Carlos Raúl Perasso.)
4168 Changes affecting past timestamps:
4170 Fix some historical data for Palestine to agree with that of
4171 timeanddate.com, as follows:
4173 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
4176 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
4179 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
4181 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
4183 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
4185 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
4187 Fix times of habitation for Macquarie to agree with the Tasmania
4188 Parks & Wildlife Service history, which indicates that permanent
4189 habitation was 1899-1919 and 1948 on.
4191 Changing affecting metadata only:
4193 Macquarie Island is politically part of Australia, not Antarctica.
4194 (Thanks to Tobias Conradi.)
4196 Sort Macquarie more consistently with other parts of Australia.
4197 (Thanks to Tim Parenti.)
4200 Release 2013b - 2013-03-10 22:33:40 -0700
4202 Changes affecting current and future timestamps:
4204 Haiti uses US daylight-saving rules this year, and presumably future years.
4205 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
4207 Paraguay will end DST on March 24 this year.
4208 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
4210 Morocco does not observe DST during Ramadan;
4211 try to predict Ramadan in Morocco as best we can.
4212 (Thanks to Erik Homoet for the heads-up.)
4214 Changes affecting commentary:
4216 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
4217 Update URL for Solaris. Mention Internet RFC 6557.
4218 Update Internet RFCs 2445->5545, 2822->5322.
4219 Switch from FTP to HTTP for Internet RFCs.
4222 Release 2013a - 2013-02-27 09:20:35 -0800
4224 Change affecting binary data format:
4226 The zone offset at the end of version-2-format zone files is now
4227 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
4229 Changes affecting current and future timestamps:
4231 Chile's 2013 rules, and we guess rules for 2014 and later, will be
4232 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
4233 (Thanks to Steffen Thorsen and Robert Elz.)
4235 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
4236 (Thanks to Tobias Conradi and Arthur David Olson.)
4238 Many changes affect historical timestamps before 1940.
4239 These were deduced from: Milne J. Civil time. Geogr J. 1899
4240 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
4242 Changes affecting the code:
4244 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
4245 the data). (Thanks to Arthur David Olson.)
4247 Fix localtime bug when time_t is unsigned and data files were generated
4248 by a signed time_t system. (Thanks to Doug Bailey for reporting and
4249 to Arthur David Olson for fixing.)
4251 Allow the email address for bug reports to be set by the packager.
4252 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
4254 Update HTML checking to be compatible with Ubuntu 12.10.
4256 Check that files are a safe subset of ASCII. At some point we may
4257 relax this requirement to a safe subset of UTF-8. Without the
4258 check, some non-UTF-8 encodings were leaking into the distribution.
4262 Restore a comment about copyright notices that was inadvertently deleted.
4263 (Thanks to Arthur David Olson.)
4265 Improve the commentary about which districts observe what times
4266 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
4268 Add web page links to tz.js.
4270 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
4273 Release 2012j - 2012-11-12 18:34:49 -0800
4275 Libya moved to CET this weekend, but with DST planned next year.
4276 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
4278 Signatures now have the extension .asc, not .sign, as that's more
4279 standard. (Thanks to Phil Pennock.)
4281 The output of 'zdump --version', and of 'zic --version', now
4282 uses a format that is more typical for --version.
4283 (Thanks to Joseph S. Myers.)
4285 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
4286 now uses tz@iana.org rather than the old elsie address.
4288 zic -v now complains about abbreviations that are less than 3
4289 or more than 6 characters, as per Posix. Formerly, it checked
4290 for abbreviations that were more than 3.
4292 'make public' no longer puts its temporary directory under /tmp,
4293 and uses the just-built zic rather than the system zic.
4295 Various fixes to documentation and commentary.
4298 Release 2012i - 2012-11-03 12:57:09 -0700
4300 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
4302 Linker flags can now be specified via LDFLAGS.
4303 AWK now defaults to 'awk', not 'nawk'.
4304 The shell in tzselect now defaults to /bin/bash, but this can
4305 be overridden by specifying KSHELL.
4306 The main web page now mentions the unofficial GitHub repository.
4307 (Thanks to Mike Frysinger.)
4309 Tarball signatures can now be built by running 'make signatures'.
4310 There are also new makefile rules 'tarballs', 'check_public', and
4311 separate makefile rules for each tarball and signature file.
4312 A few makefile rules are now more portable to strict POSIX.
4314 The main web page now lists the canonical IANA URL.
4317 Release 2012h - 2012-10-26 22:49:10 -0700
4319 Bahia no longer has DST. (Thanks to Kelley Cook.)
4321 Tocantins has DST. (Thanks to Rodrigo Severo.)
4323 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
4325 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
4329 More C modernization, except that at Arthur David Olson's suggestion
4330 the instances of 'register' were kept.
4333 Release 2012g - 2012-10-17 20:59:45 -0700
4335 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
4337 Palestine fall 2012. (Thanks to Steffen Thorsen.)
4341 To attack the version-number problem, this release ships the file
4342 'Makefile' (which contains the release number) in both the tzcode and
4343 the tzdata tarballs. The two Makefiles are identical, and should be
4344 identical in any matching pair of tarballs, so it shouldn't matter
4345 which order you extract the tarballs. Perhaps we can come up with a
4346 better version-number scheme at some point; this scheme does have the
4347 virtue of not adding more files.
4350 Release 2012f - 2012-09-12 23:17:03 -0700
4352 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4353 20 this year. (Thanks to Steffen Thorsen.)
4356 Release 2012e - 2012-08-02 20:44:55 -0700
4358 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4359 (Thanks to Steffen Thorsen.)
4361 * Use a single version number for both code and data.
4363 * .gitignore: New file.
4365 * Remove trailing white space.
4368 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4370 Changes for Morocco's timestamps, which take effect in a couple of
4371 hours, along with infrastructure changes to accommodate how the tz
4372 code and data are released on IANA.
4375 Release data2012c - 2012-03-27 12:17:25 -0400
4378 Summer time changes for Morocco (to start late April 2012)
4381 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4384 Haiti following US/Canada rules for 2012 (and we're assuming,
4385 for now anyway, for the future).
4388 Release 2012b - 2012-03-02 12:29:15 +0700
4390 There is just one change to tzcode2012b (compared with 2012a):
4391 the Makefile that was accidentally included with 2012a has been
4392 replaced with the version that should have been there, which is
4393 identical with the previous version (from tzcode2011i).
4395 There are just two changes in tzdata2012b compared with 2012a.
4397 Most significantly, summer time in Cuba has been delayed 3 weeks
4398 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4399 date, as listed in 2012a) is just a little over a week away, this
4402 Less importantly, an excess tab in one of the changes in zone.tab
4403 in 2012a has been removed.
4406 Release 2012a - 2012-03-01 18:28:10 +0700
4408 The changes in tzcode2012a (compared to the previous version, 2011i)
4409 are entirely to the README and tz-art.htm and tz-link.htm files, if
4410 none of those concern you, you can ignore the code update. The changes
4411 reflect the changed addresses for the mailing list and the code and
4412 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4413 has been added to tz-link.htm).
4415 In tzdata2012a (compared to the previous release, which was 2011n)
4416 the major changes are:
4417 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4418 Falkland Islands onto permanent summer time (we're assuming for the
4419 foreseeable future, though 2012 is all we're fairly certain of.)
4420 Armenia has abolished Summer Time.
4421 Tokelau jumped the International Date Line back last December
4422 (just the same as their near neighbour, Samoa).
4423 America/Creston is a new zone for a small area of British Columbia
4424 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4426 Other minor changes are:
4427 Corrections to 1918 Canadian summer time end dates.
4428 Updated URL for UK time zone history (in comments)
4429 A few typos in Le Corre's list of free French place names (comments)
4432 Release data2011n - 2011-10-30 14:57:54 +0700
4434 There are three changes of note - most urgently, Cuba (America/Havana)
4435 has extended summer time by two weeks, now to end on Nov 13, rather than
4436 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4437 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4438 all, and consequently that zone has been removed (again) and reinstated
4439 in the "backward" file as a link to Europe/Chisinau. And third, the
4440 end date for Fiji's summer time this summer was moved forward from the
4441 earlier planned Feb 26, to Jan 22.
4443 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4444 (and the incorrect syntax that was in the 2011m version of that file
4445 is so fixed - it would have been fixed in a different way had this
4446 change not happened - that's the "missing" sccs version id).
4449 Release data2011m - 2011-10-24 21:42:16 +0700
4451 In particular, the typos in comments in the data (2011-11-17 should have
4452 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4453 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4454 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
4455 Tim Parenti, and also Denys Gavrysh)
4457 In addition, I added Europe/Tiraspol to zone.tab.
4459 This time, all the files have new version numbers... (including the files
4460 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4461 version numbers there...)
4464 Release data2011l - 2011-10-10 11:15:43 +0700
4466 There are just 2 changes that cause different generated tzdata files from
4467 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4468 is included, but commented out. Compared with the diff I sent out last week,
4469 this version also includes attributions for the sources for the changes
4470 (in much the same format as ado used, but the html tags have not been
4471 checked, verified, or used in any way at all, so if there are errors there,
4472 please let me know.)
4475 Release data2011k - 2011-09-20 17:54:03 -0400
4480 Release data2011j - 2011-09-12 09:22:49 -0400
4482 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4483 Tanzania); there are also two spelling corrections to comments in
4484 the australasia file (with thanks to Christos Zoulas).
4487 Release 2011i - 2011-08-29 05:56:32 -0400
4492 Release data2011h - 2011-06-15 18:41:48 -0400
4494 Russia and Curaçao changes
4497 Release 2011g - 2011-04-25 09:07:22 -0400
4499 update the rules for Egypt to reflect its abandonment of DST this year
4502 Release 2011f - 2011-04-06 17:14:53 -0400
4507 Release 2011e - 2011-03-31 16:04:38 -0400
4509 Morocco, Chile, and tz-link changes
4512 Release 2011d - 2011-03-14 09:18:01 -0400
4514 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4517 Release 2011c - 2011-03-07 09:30:09 -0500
4519 These do affect current timestamps in Chile and Annette Island, Canada.
4522 Release 2011b - 2011-02-07 08:44:50 -0500
4527 Release 2011a - 2011-01-24 10:30:16 -0500
4532 Release data2010o - 2010-11-01 09:18:23 -0400
4534 change to the end of DST in Fiji in 2011
4537 Release 2010n - 2010-10-25 08:19:17 -0400
4542 Release 2010m - 2010-09-27 09:24:48 -0400
4544 Hong Kong, Vostok, and zic.c changes
4547 Release 2010l - 2010-08-16 06:57:25 -0400
4552 Release 2010k - 2010-07-26 10:42:27 -0400
4557 Release 2010j - 2010-05-10 09:07:48 -0400
4559 changes for Bahía de Banderas and for version naming
4562 Release data2010i - 2010-04-16 18:50:45 -0400
4564 the end of DST in Morocco on 2010-08-08
4567 Release data2010h - 2010-04-05 09:58:56 -0400
4572 Release data2010g - 2010-03-24 11:14:53 -0400
4577 Release 2010f - 2010-03-22 09:45:46 -0400
4582 Release data2010e - 2010-03-08 14:24:27 -0500
4584 corrects the Dhaka bug found by Danvin Ruangchan
4587 Release data2010d - 2010-03-06 07:26:01 -0500
4592 Release 2010c - 2010-03-01 09:20:58 -0500
4594 changes including KRE's suggestion for earlier initialization of
4595 "goahead" and "goback" structure elements
4598 Release code2010a - 2010-02-16 10:40:04 -0500
4603 Release data2010b - 2010-01-20 12:37:01 -0500
4608 Release data2010a - 2010-01-18 08:30:04 -0500
4613 Release data2009u - 2009-12-26 08:32:28 -0500
4615 changes to DST in Bangladesh
4618 Release 2009t - 2009-12-21 13:24:27 -0500
4623 Release data2009s - 2009-11-14 10:26:32 -0500
4625 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4628 Release 2009r - 2009-11-09 10:10:31 -0500
4630 "antarctica" and "tz-link.htm" changes
4633 Release 2009q - 2009-11-02 09:12:40 -0500
4635 with two corrections as reported by Eric Muller and Philip Newton
4638 Release data2009p - 2009-10-23 15:05:27 -0400
4640 Argentina (including San Luis) changes (with the correction from
4644 Release data2009o - 2009-10-14 16:49:38 -0400
4646 Samoa (commentary only), Pakistan, and Bangladesh changes
4649 Release data2009n - 2009-09-22 15:13:38 -0400
4651 added commentary for Argentina and a change to the end of DST in
4655 Release data2009m - 2009-09-03 10:23:43 -0400
4657 Samoa and Palestine changes
4660 Release data2009l - 2009-08-14 09:13:07 -0400
4662 Samoa (comments only) and Egypt
4665 Release 2009k - 2009-07-20 09:46:08 -0400
4670 Release data2009j - 2009-06-15 06:43:59 -0400
4672 Bangladesh change (with a short turnaround since the DST change is
4676 Release 2009i - 2009-06-08 09:21:22 -0400
4678 updating for DST in Bangladesh this year
4681 Release 2009h - 2009-05-26 09:19:14 -0400
4686 Release data2009g - 2009-04-20 16:34:07 -0400
4691 Release data2009f - 2009-04-10 11:00:52 -0400
4693 correct DST in Pakistan
4696 Release 2009e - 2009-04-06 09:08:11 -0400
4701 Release 2009d - 2009-03-23 09:38:12 -0400
4703 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4706 Release data2009c - 2009-03-16 09:47:51 -0400
4708 change to the start of Cuban DST
4711 Release 2009b - 2009-02-09 11:15:22 -0500
4716 Release 2009a - 2009-01-21 10:09:39 -0500
4721 Release data2008i - 2008-10-21 12:10:25 -0400
4723 southamerica and zone.tab files, with Argentina DST rule changes and
4724 United States zone reordering and recommenting
4727 Release 2008h - 2008-10-13 07:33:56 -0400
4732 Release 2008g - 2008-10-06 09:03:18 -0400
4734 Fix a broken HTML anchor and update Brazil's DST transitions;
4735 there's also a slight reordering of information in tz-art.htm.
4738 Release data2008f - 2008-09-09 22:33:26 -0400
4743 Release 2008e - 2008-07-28 14:11:17 -0400
4745 changes by Arthur David Olson and Jesper Nørgaard Welen
4748 Release data2008d - 2008-07-07 09:51:38 -0400
4750 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4753 Release data2008c - 2008-05-19 17:48:03 -0400
4755 Pakistan, Morocco, and Mongolia
4758 Release data2008b - 2008-03-24 08:30:59 -0400
4760 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4764 Release 2008a - 2008-03-08 05:42:16 -0500
4769 Release 2007k - 2007-12-31 10:25:22 -0500
4771 most importantly, changes to the "southamerica" file based on
4772 Argentina's readoption of daylight saving time
4775 Release 2007j - 2007-12-03 09:51:01 -0500
4777 1. eliminate the "P" (parameter) macro;
4779 2. the "noncontroversial" changes circulated on the time zone
4780 mailing list (less the changes to "logwtmp.c");
4782 3. eliminate "too many transition" errors when "min" is used in time
4785 4. changes by Paul Eggert (including updated information for Venezuela).
4788 Release data2007i - 2007-10-30 10:28:11 -0400
4790 changes for Cuba and Syria
4793 Release 2007h - 2007-10-01 10:05:51 -0400
4795 changes by Paul Eggert, as well as an updated link to the ICU
4796 project in tz-link.htm
4799 Release 2007g - 2007-08-20 10:47:59 -0400
4801 changes by Paul Eggert
4803 The "leapseconds" file has been updated to incorporate the most
4804 recent International Earth Rotation and Reference Systems Service
4807 There's an addition to tz-art.htm regarding the television show "Medium".
4810 Release 2007f - 2007-05-07 10:46:46 -0400
4812 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4815 changes to zic.c to allow hour values greater than 24 (along with
4816 Paul's improved time value overflow checking)
4819 Release 2007e - 2007-04-02 10:11:52 -0400
4821 Syria and Honduras changes by Paul Eggert
4823 zic.c variable renaming changes by Arthur David Olson
4826 Release 2007d - 2007-03-20 08:48:30 -0400
4828 changes by Paul Eggert
4830 the elimination of white space at the ends of lines
4833 Release 2007c - 2007-02-26 09:09:37 -0500
4835 changes by Paul Eggert
4838 Release 2007b - 2007-02-12 09:34:20 -0500
4840 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4842 changes to the commentary in "leapseconds" reflecting the IERS
4843 announcement that there is to be no positive leap second at the end
4847 Release 2007a - 2007-01-08 12:28:29 -0500
4849 changes by Paul Eggert
4851 Derick Rethans's Asmara change
4853 Oscar van Vlijmen's Easter Island local mean time change
4855 symbolic link changes
4858 Release 2006p - 2006-11-27 08:54:27 -0500
4860 changes by Paul Eggert
4863 Release 2006o - 2006-11-06 09:18:07 -0500
4865 changes by Paul Eggert
4868 Release 2006n - 2006-10-10 11:32:06 -0400
4870 changes by Paul Eggert
4873 Release 2006m - 2006-10-02 15:32:35 -0400
4875 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4877 (minimalist) changes to zic.8 to clarify "until" information
4880 Release data2006l - 2006-09-18 12:58:11 -0400
4882 Paul's best-effort work on this coming weekend's Egypt time change
4885 Release 2006k - 2006-08-28 12:19:09 -0400
4887 changes by Paul Eggert
4890 Release 2006j - 2006-08-21 09:56:32 -0400
4892 changes by Paul Eggert
4895 Release code2006i - 2006-08-07 12:30:55 -0400
4899 Ken Pizzini's conversion script
4902 Release code2006h - 2006-07-24 09:19:37 -0400
4904 adds public domain notices to four files
4906 includes a fix for transition times being off by a second
4908 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4911 Release 2006g - 2006-05-08 17:18:09 -0400
4913 northamerica changes by Paul Eggert
4916 Release 2006f - 2006-05-01 11:46:00 -0400
4918 a missing version number problem is fixed (with thanks to Bradley
4919 White for catching the problem)
4922 Release 2006d - 2006-04-17 14:33:43 -0400
4924 changes by Paul Eggert
4926 added new items to tz-arts.htm that were found by Paul
4929 Release 2006c - 2006-04-03 10:09:32 -0400
4931 two sets of data changes by Paul Eggert
4933 a fencepost error fix in zic.c
4935 changes to zic.c and the "europe" file to minimize differences
4936 between output produced by the old 32-bit zic and the new 64-bit
4940 Release 2006b - 2006-02-20 10:08:18 -0500
4941 [tz32code2006b + tz64code2006b + tzdata2006b]
4945 All SCCS IDs were bumped to "8.1" for this release.
4948 Release 2006a - 2006-01-30 08:59:31 -0500
4950 changes by Paul Eggert (in particular, Indiana time zone moves)
4952 an addition to the zic manual page to describe how special-case
4953 transitions are handled
4956 Release 2005r - 2005-12-27 09:27:13 -0500
4958 Canadian changes by Paul Eggert
4960 They also add "<pre>" directives to time zone data files and reflect
4961 changes to warning message logic in "zdump.c" (but with calls to
4962 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4965 Release 2005q - 2005-12-13 09:17:09 -0500
4967 Nothing earth-shaking here:
4968 1. Electronic mail addresses have been removed.
4969 2. Casts of the return value of exit have been removed.
4970 3. Casts of the argument of is.* macros have been added.
4971 4. Indentation in one section of zic.c has been fixed.
4972 5. References to dead URLs in the data files have been dealt with.
4975 Release 2005p - 2005-12-05 10:30:53 -0500
4977 "systemv", "tz-link.htm", and "zdump.c" changes
4978 (less the casts of arguments to the is* macros)
4981 Release 2005o - 2005-11-28 10:55:26 -0500
4983 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4985 zdump.c lint fixes by Arthur David Olson
4988 Release 2005n - 2005-10-03 09:44:09 -0400
4990 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4994 Release 2005m - 2005-08-29 12:15:40 -0400
4996 changes by Paul Eggert (with a small tweak to the tz-art change)
4998 a declaration of an unused variable has been removed from zdump.c
5001 Release 2005l - 2005-08-22 12:06:39 -0400
5003 changes by Paul Eggert
5005 overflow/underflow checks by Arthur David Olson, minus changes to
5006 the "Theory" file about the pending addition of 64-bit data (I grow
5007 less confident of the changes being accepted with each passing day,
5008 and the changes no longer increase the data files nine-fold--there's
5009 less than a doubling in size by my local Sun's reckoning)
5012 Release 2005k - 2005-07-14 14:14:24 -0400
5014 The "leapseconds" file has been edited to reflect the recently
5015 announced leap second at the end of 2005.
5017 I've also deleted electronic mail addresses from the files as an
5021 Release 2005j - 2005-06-13 14:34:13 -0400
5023 These reflect changes to limit the length of time zone abbreviations
5024 and the characters used in those abbreviations.
5026 There are also changes to handle POSIX-style "quoted" timezone
5027 environment variables.
5029 The changes were circulated on the time zone mailing list; the only
5030 change since then was the removal of a couple of minimum-length of
5031 abbreviation checks.
5034 Release data2005i - 2005-04-21 15:04:16 -0400
5036 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
5039 Release 2005h - 2005-04-04 11:24:47 -0400
5041 changes by Paul Eggert
5043 minor changes to Makefile and zdump.c to produce more useful output
5044 when doing a "make typecheck"
5047 Release 2005g - 2005-03-14 10:11:21 -0500
5049 changes by Paul Eggert (a change to current DST rules in Uruguay and
5050 an update to a link to time zone software)
5053 Release 2005f - 2005-03-01 08:45:32 -0500
5055 data and documentation changes by Paul Eggert
5058 Release 2005e - 2005-02-10 15:59:44 -0500
5063 Release code2005d - 2005-01-31 09:21:47 -0500
5065 make zic complain about links to links if the -v flag is used
5067 have "make public" do more code checking
5069 add an include to "localtime.c" for the benefit of gcc systems
5072 Release 2005c - 2005-01-17 18:36:29 -0500
5074 get better results when mktime runs on a system where time_t is double
5076 changes to the data files (most importantly to Paraguay)
5079 Release 2005b - 2005-01-10 09:19:54 -0500
5081 Get localtime and gmtime working on systems with exotic time_t types.
5083 Update the leap second commentary in the "leapseconds" file.
5086 Release 2005a - 2005-01-01 13:13:44 -0500
5091 Release code2004i - 2004-12-14 13:42:58 -0500
5093 Deal with systems where time_t is unsigned.
5096 Release code2004h - 2004-12-07 11:40:18 -0500
5098 64-bit-time_t changes
5101 Release 2004g - 2004-11-02 09:06:01 -0500
5103 update to Cuba (taking effect this weekend)
5105 other changes by Paul Eggert
5107 correction of the spelling of Oslo
5109 changed versions of difftime.c and private.h
5112 Release code2004f - 2004-10-21 10:25:22 -0400
5114 Cope with wide-ranging tm_year values.
5117 Release 2004e - 2004-10-11 14:47:21 -0400
5119 Brazil/Argentina/Israel changes by Paul Eggert
5121 changes to tz-link.htm by Paul
5123 one small fix to Makefile
5126 Release 2004d - 2004-09-22 08:27:29 -0400
5128 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
5131 Release 2004c - 2004-08-11 12:06:26 -0400
5133 asctime-related changes
5135 (variants of) some of the documentation changes suggested by Paul Eggert
5138 Release 2004b - 2004-07-19 14:33:35 -0400
5140 data changes by Paul Eggert - most importantly, updates for Argentina
5143 Release 2004a - 2004-05-27 12:00:47 -0400
5145 changes by Paul Eggert
5147 Handle DST transitions that occur at the end of a month in some
5148 years but at the start of the following month in other years.
5150 Add a copy of the correspondence that's the basis for claims about
5151 DST in the Navajo Nation.
5154 Release 2003e - 2003-12-15 09:36:47 -0500
5156 changes by Arthur David Olson (primarily code changes)
5158 changes by Paul Eggert (primarily data changes)
5160 minor changes to "Makefile" and "northamerica" (in the latter case,
5161 optimization of the "Toronto" rules)
5164 Release 2003d - 2003-10-06 09:34:44 -0400
5166 changes by Paul Eggert
5169 Release 2003c - 2003-09-16 10:47:05 -0400
5171 Fix bad returns in zic.c's inleap function.
5172 Thanks to Bradley White for catching the problem!
5175 Release 2003b - 2003-09-16 07:13:44 -0400
5177 Add a "--version" option (and documentation) to the zic and zdump commands.
5179 changes to overflow/underflow checking in zic
5181 a localtime typo fix.
5183 Update the leapseconds and tz-art.htm files.
5186 Release 2003a - 2003-03-24 09:30:54 -0500
5188 changes by Paul Eggert
5190 a few additions and modifications to the tz-art.htm file
5193 Release 2002d - 2002-10-15 13:12:42 -0400
5195 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
5197 There's also a new time zone quote in "tz-art.htm".
5200 Release 2002c - 2002-04-04 11:55:20 -0500
5202 changes by Paul Eggert
5204 Change zic.c to avoid creating symlinks to files that don't exist.
5207 Release 2002b - 2002-01-28 12:56:03 -0500
5209 [These change notes are for Release 2002a, which was corrupted.
5210 2002b was a corrected version of 2002a.]
5212 changes by Paul Eggert
5214 Update the "leapseconds" file to note that there'll be no leap
5215 second at the end of June, 2002.
5217 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
5219 Change to "difftime.c" to avoid sizeof problems.
5222 Release 2001d - 2001-10-09 13:31:32 -0400
5224 changes by Paul Eggert
5227 Release 2001c - 2001-06-05 13:59:55 -0400
5229 changes by Paul Eggert and Andrew Brown
5232 Release 2001b - 2001-04-05 16:44:38 -0400
5234 changes by Paul Eggert (modulo jnorgard's typo fix)
5236 tz-art.htm has been HTMLified.
5239 Release 2001a - 2001-03-13 12:57:44 -0500
5241 changes by Paul Eggert
5243 An addition to the "leapseconds" file: comments with the text of the
5244 latest IERS leap second notice.
5246 Trailing white space has been removed from data file lines, and
5247 repeated spaces in "Rule Jordan" lines in the "asia" file have been
5251 Release 2000h - 2000-12-14 15:33:38 -0500
5253 changes by Paul Eggert
5255 one typo fix in the "art" file
5257 With providence, this is the last update of the millennium.
5260 Release 2000g - 2000-10-10 11:35:22 -0400
5262 changes by Paul Eggert
5264 correction of John Mackin's name submitted by Robert Elz
5266 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
5267 Emmy Awards broadcast.
5270 Release 2000f - 2000-08-10 09:31:58 -0400
5272 changes by Paul Eggert
5274 Added information in "tz-art.htm" on a Seinfeld reference to DST.
5276 Error checking and messages in the "yearistype" script have been
5280 Release 2000e - 2000-07-31 09:27:54 -0400
5282 data changes by Paul Eggert
5284 a change to the default value of the defined constant HAVE_STRERROR
5286 the addition of a Dave Barry quote on DST to the tz-arts file
5289 Release 2000d - 2000-04-20 15:43:04 -0400
5291 changes to the documentation and code of strftime for C99 conformance
5293 a bug fix for date.c
5295 These are based on (though modified from) changes by Paul Eggert.
5298 Release 2000c - 2000-03-04 10:31:43 -0500
5300 changes by Paul Eggert
5303 Release 2000b - 2000-02-21 12:16:29 -0500
5305 changes by Paul Eggert and Joseph Myers
5307 modest tweaks to the tz-art.htm and tz-link.htm files
5310 Release 2000a - 2000-01-18 09:21:26 -0500
5312 changes by Paul Eggert
5314 The two hypertext documents have also been renamed.
5317 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
5319 Paul Eggert's changes
5321 additions to the "zic" manual page and the "Arts.htm" file
5324 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
5329 Release data1999h - 1999-10-07 03:50:29 -0400
5331 changes by Paul Eggert to "europe" (most importantly, fixing
5332 Lithuania and Estonia)
5335 Release 1999g - 1999-09-28 11:06:18 -0400
5337 data changes by Paul Eggert (most importantly, the change for
5338 Lebanon that buys correctness for this coming Sunday)
5340 The "code" file contains changes to "Makefile" and "checktab.awk" to
5341 allow better checking of time zone files before they are published.
5344 Release 1999f - 1999-09-23 09:48:14 -0400
5346 changes by Arthur David Olson and Paul Eggert
5349 Release 1999e - 1999-08-17 15:20:54 -0400
5351 changes circulated by Paul Eggert, although the change to handling
5352 of DST-specifying timezone names has been commented out for now
5353 (search for "XXX" in "localtime.c" for details). These files also
5354 do not make any changes to the start of DST in Brazil.
5356 In addition to Paul's changes, there are updates to "Arts.htm" and
5360 Release 1999d - 1999-03-30 11:31:07 -0500
5362 changes by Paul Eggert
5364 The Makefile's "make public" rule has also been changed to do a test
5365 compile of each individual time zone data file (which should help
5366 avoid problems such as the one we had with Nicosia).
5369 Release 1999c - 1999-03-25 09:47:47 -0500
5371 changes by Paul Eggert, most importantly the change for Chile.
5374 Release 1999b - 1999-02-01 17:51:44 -0500
5376 changes by Paul Eggert
5378 code changes (suggested by Mani Varadarajan, mani at be.com) for
5379 correct handling of symbolic links when building using a relative directory
5381 code changes to generate correct messages for failed links
5383 updates to the URLs in Arts.htm
5386 Release 1999a - 1999-01-19 16:20:29 -0500
5388 error message internationalizations and corrections in zic.c and
5389 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5393 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5395 changes for Brazil, Chile, and Germany
5397 support for use of "24:00" in the input files for the time zone compiler
5400 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5402 changes by Paul Eggert
5404 correction to a define in the "private.h" file
5407 Release data1998g - 1998-08-11 03:28:35 -0000
5408 [tzdata1998g.tar.gz is missing!]
5410 Lithuanian change provided by mgedmin at pub.osf.it
5412 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5413 "backward") to ensure that the GMT file is created even where folks
5414 don't want the "backward" links (as suggested by Paul Eggert).
5417 Release data1998f - 1998-07-20 13:50:00 -0000
5418 [tzdata1998f.tar.gz is missing!]
5420 Update the "leapseconds" file to include the newly announced
5421 insertion at the end of 1998.
5424 Release code1998f - 1998-06-01 10:18:31 -0400
5426 addition to localtime.c by Guy Harris
5429 Release 1998e - 1998-05-28 09:56:26 -0400
5431 The Makefile is changed to produce zoneinfo-posix rather than
5432 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5435 data changes by Paul Eggert
5437 changes from Guy Harris to provide asctime_r and ctime_r
5439 A usno1998 file (substantially identical to usno1997) has been added.
5442 Release 1998d - 1998-05-14 11:58:34 -0400
5444 changes to comments (in particular, elimination of references to CIA maps).
5445 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5446 where changes occur.
5449 Release 1998c - 1998-02-28 12:32:26 -0500
5451 changes by Paul Eggert (save the "French correction," on which I'll
5452 wait for the dust to settle)
5456 changes and additions to Arts.htm
5459 Release 1998b - 1998-01-17 14:31:51 -0500
5461 URL cleanups and additions
5464 Release 1998a - 1998-01-13 12:37:35 -0500
5466 changes by Paul Eggert
5469 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5471 changes by Paul Eggert, with minor modifications from Arthur David
5472 Olson to make the files more browser friendly
5475 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5477 minor changes to put "TZif" at the start of each timezone information file
5479 a rule has also been added to the Makefile so you can
5481 to just recompile the zone information files (rather than doing a
5482 full "make install" with its other effects).
5485 Release data1997i - 1997-10-07 08:45:38 -0400
5487 changes to Africa by Paul Eggert
5490 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5492 corrections for Uruguay (and other locations)
5494 Arthur David Olson's simple-minded fix allowing mktime to both
5495 correctly handle leap seconds and correctly handle tm_sec values
5496 upon which arithmetic has been performed.
5499 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5501 Paul Eggert's updates
5503 a small change to a function prototype;
5505 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5506 include information on Around the World in Eighty Days.
5509 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5511 fixes to zic's error handling
5513 changes inspired by the item circulated on Slovenia
5515 The description of Web resources has been HTMLified for browsing
5518 A new piece of tz-related music has been added to the "Music" file.
5521 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5523 Paul Eggert's latest suggestions
5526 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5528 changes to "zic.c" to correct performance of the "-s" option
5530 a new file "usno1997"
5533 Release data1997c - 1997-03-04 09:58:18 -0500
5538 Release 1997b - 1997-02-27 18:34:19 -0500
5540 The data file incorporates the 1997 leap second.
5542 The code file incorporates Arthur David Olson's take on the
5543 zic/multiprocessor/directory-creation situation.
5546 Release 1997a - 1997-01-21 09:11:10 -0500
5548 Paul Eggert's Antarctica (and other changes)
5550 Arthur David Olson finessed the "getopt" issue by checking against
5551 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5552 is returned while SunOS 5.5's manual says EOF is returned).
5555 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5557 Paul Eggert's latest changes
5560 Release code1996n - 1996-12-16 09:42:02 -0500
5562 link snapping fix from Bruce Evans (via Garrett Wollman)
5565 Release data1996m - 1996-11-24 02:37:34 -0000
5566 [tzdata1996m.tar.gz is missing!]
5568 Paul Eggert's batch of changes
5571 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5573 No functional changes here; the files have simply been changed to
5574 make more use of ISO style dates in comments. The names of the above
5575 files now include the year in full.
5578 Release code96l - 1996-09-08 17:12:20 -0400
5580 tzcode96k was missing a couple of pieces.
5583 Release 96k - 1996-09-08 16:06:22 -0400
5585 the latest round of changes from Paul Eggert
5587 the recent Year 2000 material
5590 Release code96j - 1996-07-30 13:18:53 -0400
5592 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5595 Release code96i - 1996-07-27 20:11:35 -0400
5597 Paul's suggested patch for strftime %V week numbers
5600 Release data96i - 1996-07-01 18:13:04 -0400
5602 "northamerica" and "europe" changes by Paul Eggert
5605 Release code96h - 1996-06-05 08:02:21 -0400
5607 fix for handling transitions specified in Universal Time
5609 Some "public domain" notices have also been added.
5612 Release code96g - 1996-05-16 14:00:26 -0400
5614 fix for the simultaneous-DST-and-zone-change challenge
5617 Release data96h - 1996-05-09 17:40:51 -0400
5619 changes by Paul Eggert
5622 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5623 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5625 The changes get us some of the way to fixing the problems noted in Paul
5626 Eggert's letter yesterday (in addition to a few others). The approach
5627 has been to make zic a bit smarter about figuring out what time zone
5628 abbreviations apply just after the time specified in the "UNTIL" part
5629 of a zone line. Putting the smarts in zic means avoiding having
5630 transition times show up in both "Zone" lines and "Rule" lines, which
5631 in turn avoids multiple transition time entries in time zone files.
5632 (This also makes the zic input files such as "europe" a bit shorter and
5633 should ease maintenance.)
5636 Release data96f - 1996-04-19 19:20:03 -0000
5637 [tzdata96f.tar.gz is missing!]
5639 The only changes are to the "northamerica" file; the time zone
5640 abbreviation for Denver is corrected to MST (and MDT), and the
5641 comments for Mexico have been updated.
5644 Release data96e - 1996-03-19 17:37:26 -0500
5646 Proposals by Paul Eggert, in particular the Portugal change that
5647 comes into play at the end of this month.
5650 Release data96d - 1996-03-18 20:49:39 -0500
5655 Release code96e - 1996-02-29 15:43:27 -0000
5656 [tzcode96e.tar.gz is missing!]
5658 internationalization changes and the fix to the documentation for strftime
5661 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5663 The "code" file simply updates Bob Kridle's electronic address.
5665 The "data" file updates rules for Mexico.
5668 Release data96b - 1996-01-27 15:44:42 -0500
5673 Release code96c - 1996-01-16 16:58:15 -0500
5675 leap-year streamlining and binary-search changes
5680 Release code96b - 1996-01-10 20:42:39 -0500
5682 fixes and enhancements from Paul Eggert, including code that
5683 emulates the behavior of recent versions of the SunOS "date"
5687 Release 96a - 1996-01-06 09:08:24 -0500
5691 fixes to strftime.c for correct ISO 8601 week number generation,
5692 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5693 numbers (which are not necessarily the same as calendar year numbers)
5696 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5698 The latest revisions from Paul Eggert are included, the usno1995
5699 file has been updated, and a new file ("WWW") covering useful URLs
5703 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5705 A simplification of a macro definition, a change to data for Sudan,
5706 and (for last minute shoppers) notes in the "Music" file on the CD
5710 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5712 (slightly reformatted) 8-bit-clean proposed patch
5714 minor patch: US/Eastern -> America/New_York
5716 snapshot of the USNO's latest data ("usno1995")
5718 some other minor cleanups
5721 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5722 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5726 support for 64-bit time_t's
5728 optimization in localtime.c
5731 Release code95e - 1995-10-13 13:23:57 -0400
5733 the mktime change to scan from future to past when trying to find time zone
5737 Release data95i - 1995-09-26 10:43:26 -0400
5739 For Canada/Central, guess that the Sun customer's "one week too
5740 early" was just a approximation, and the true error is one month
5741 too early. This is consistent with the rest of Canada.
5744 Release data95h - 1995-09-21 11:26:48 -0400
5746 latest changes from Paul Eggert
5749 Release code95d - 1995-09-14 11:14:45 -0400
5751 the addition of a "Music" file, which documents four recorded
5752 versions of the tune "Save That Time".
5755 Release data95g - 1995-09-01 17:21:36 -0400
5757 "yearistype" correction
5760 Release data95f - 1995-08-28 20:46:56 -0400
5762 Paul Eggert's change to the australasia file
5765 Release data95e - 1995-07-08 18:02:34 -0400
5767 The only change is a leap second at the end of this year.
5768 Thanks to Bradley White for forwarding news on the leap second.
5771 Release data95d - 1995-07-03 13:26:22 -0400
5773 Paul Eggert's changes
5776 Release data95c - 1995-07-02 19:19:28 -0400
5778 changes to "asia", "backward", "europe", and "southamerica"
5779 (read: northamericacentrics need not apply)
5782 Release code95c - 1995-03-13 14:00:46 -0500
5784 one-line fix for sign extension problems in detzcode
5787 Release 95b - 1995-03-04 11:22:38 -0500
5789 Minor changes in both:
5791 The "code" file contains a workaround for the lack of "unistd.h" in
5792 Microsoft C++ version 7.
5794 The "data" file contains a fixed "Link" for America/Shiprock.
5797 Release 94h - 1994-12-10 12:51:14 -0500
5801 * incorporate the changes to "zdump" and "date" to make changes to
5802 the "TZ" environment variable permanent;
5804 * incorporate the table changes by Paul Eggert;
5806 * include (and document) support for universal time specifications in
5807 data files - but do not (yet) include use of this feature in the
5810 Think of this as "TZ Classic" - the software has been set up not to break if
5811 universal time shows up in its input, and data entries have been
5812 left as is so as not to break existing implementations.
5815 Release data94f - 1994-08-20 12:56:09 -0400
5817 (with thanks!) the latest data updates from Paul Eggert
5820 Release data94e - 1994-06-04 13:13:53 -0400
5825 Release code94g - 1994-05-05 12:14:07 -0400
5827 fix missing "optind.c" and a reference to it in the Makefile
5830 Release code94f - 1994-05-05 13:00:33 -0000
5831 [tzcode94f.tar.gz is missing!]
5833 changes to avoid overflow in difftime, as well as changes to cope
5834 with the 52/53 challenge in strftime
5837 Release code94e - 1994-03-30 23:32:59 -0500
5839 change for the benefit of PCTS
5842 Release 94d - 1994-02-24 15:42:25 -0500
5844 Avoid clashes with POSIX semantics for zones such as GMT+4.
5846 Some other very minor housekeeping is also present.
5849 Release code94c - 1994-02-10 08:52:40 -0500
5851 Fix bug where mkdirs was broken unless you compile with
5852 -fwritable-strings (which is generally losing to do).
5855 Release 94b - 1994-02-07 10:04:33 -0500
5857 work by Paul Eggert who notes:
5859 I found another book of time zone histories by E W Whitman; it's not
5860 as extensive as Shanks but has a few goodies of its own. I used it
5861 to update the tables. I also fixed some more as a result of
5862 correspondence with Adam David and Peter Ilieve, and move some stray
5863 links from 'europe' to 'backward'. I corrected some scanning errors
5866 As far as the code goes, I fixed zic to allow years in the range
5867 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5868 And I cleaned up the zic documentation a little bit.
5871 Release data94a - 1994-02-03 08:58:54 -0500
5873 It simply incorporates the recently announced leap second into the
5877 Release 93g - 1993-11-22 17:28:27 -0500
5879 Paul Eggert has provided a good deal of historic information (based
5880 on Shanks), and there are some code changes to deal with the buglets
5881 that crawled out in dealing with the new information.
5884 Release 93f - 1993-10-15 12:27:46 -0400
5886 Paul Eggert's changes
5889 Release 93e - 1993-09-05 21:21:44 -0400
5891 This has updated data for Israel, England, and Kwajalein. There's
5892 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5893 Thanks to Paul Eggert and Peter Ilieve for the changes.
5896 Release 93d - 1993-06-17 23:34:17 -0400
5898 new fix and new data on Israel
5901 Release 93c - 1993-06-06 19:31:55 -0400
5906 Release 93b - 1993-02-02 14:53:58 -0500
5908 updated "leapseconds" file
5911 Release 93 - 1993-01-08 07:01:06 -0500
5913 At kre's suggestion, the package has been split in two - a code piece
5914 (which also includes documentation) that's only of use to folks who
5915 want to recompile things and a data piece useful to anyone who can
5918 The new version has a few changes to the data files, a few
5919 portability changes, and an off-by-one fix (with thanks to
5920 Tom Karzes at deshaw.com for providing a description and a
5924 Release 92c - 1992-11-21 17:35:36 -0000
5925 [tz92c.tar.Z is missing!]
5927 The fallout from the latest round of DST transitions.
5929 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5930 there's also a change to "zic.c" that makes it portable to more systems.
5933 Release 92 - 1992-04-25 18:17:03 -0000
5934 [tz92.tar.Z is missing!]
5936 By popular demand (well, at any rate, following a request by kre at munnari)
5939 The 1989 update of the time zone package featured:
5941 * POSIXization (including interpretation of POSIX-style TZ environment
5942 variables, provided by Guy Harris),
5943 * ANSIfication (including versions of "mktime" and "difftime"),
5944 * SVIDulation (an "altzone" variable)
5945 * MACHination (the "gtime" function)
5946 * corrections to some time zone data (including corrections to the rules
5947 for Great Britain and New Zealand)
5948 * reference data from the United States Naval Observatory for folks who
5949 want to do additional time zones
5950 * and the 1989 data for Saudi Arabia.
5952 (Since this code will be treated as "part of the implementation" in some
5953 places and as "part of the application" in others, there's no good way to
5954 name functions, such as timegm, that are not part of the proposed ANSI C
5955 standard; such functions have kept their old, underscore-free names in this
5958 And the "dysize" function has disappeared; it was present to allow
5959 compilation of the "date" command on old BSD systems, and a version of "date"
5960 is now provided in the package. The "date" command is not created when you
5961 "make all" since it may lack options provided by the version distributed with
5962 your operating system, or may not interact with the system in the same way
5963 the native version does.
5965 Since POSIX frowns on correct leap second handling, the default behavior of
5966 the "zic" command (in the absence of a "-L" option) has been changed to omit
5967 leap second information from its output files.
5973 This file contains copies of the part of each release announcement
5974 that talks about the changes in that release. The text has been
5975 adapted and reformatted for the purposes of this file.
5977 Traditionally a release R consists of a pair of tarball files,
5978 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5979 code2010a, data2012c) consist of just one or the other tarball, and a
5980 few (e.g., code2012c-data2012d) have tarballs with mixed version
5981 numbers. Recent releases also come in an experimental format
5982 consisting of a single tarball tzdb-R.tar.lz with extra data.
5984 Release timestamps are taken from the release's commit (for newer,
5985 Git-based releases), from the newest file in the tarball (for older
5986 releases, where this info is available) or from the email announcing
5987 the release (if all else fails; these are marked with a time zone
5988 abbreviation of -0000 and an "is missing!" comment).
5990 Earlier versions of the code and data were not announced on the tz
5991 list and are not summarized here.
5993 This file is in the public domain.