1 News for the tz database
3 Release 2022e - 2022-10-11 11:13:02 -0700
6 Jordan and Syria switch from +02/+03 with DST to year-round +03.
8 Changes to future timestamps
10 Jordan and Syria are abandoning the DST regime and are changing to
11 permanent +03, so they will not fall back from +03 to +02 on
12 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.)
14 Changes to past timestamps
16 On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00.
18 Changes to past time zone abbreviations and DST flags
20 The temporary advancement of clocks in central Mexico in summer
21 1931 is now treated as daylight saving time, instead of as two
22 changes to standard time.
25 Release 2022d - 2022-09-23 12:02:57 -0700
28 Palestine transitions are now Saturdays at 02:00.
29 Simplify three Ukraine zones into one.
31 Changes to future timestamps
33 Palestine now springs forward and falls back at 02:00 on the
34 first Saturday on or after March 24 and October 24, respectively.
35 This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00.
36 (Thanks to Heba Hamad.)
38 Changes to past timestamps
40 Simplify three Ukraine zones to one, since the post-1970
41 differences seem to have been imaginary. Move Europe/Uzhgorod and
42 Europe/Zaporozhye to 'backzone'; backward-compatibility links
43 still work, albeit with different timestamps before October 1991.
46 Release 2022c - 2022-08-15 17:47:18 -0700
49 Work around awk bug in FreeBSD, macOS, etc.
50 Improve tzselect on intercontinental Zones.
54 Work around a bug in onetrueawk that broke commands like
55 'make traditional_tarballs' on FreeBSD, macOS, etc.
56 (Problem reported by Deborah Goldsmith.)
58 Add code to tzselect that uses experimental structured comments in
59 zone1970.tab to clarify whether Zones like Africa/Abidjan and
60 Europe/Istanbul cross continent or ocean boundaries.
61 (Inspired by a problem reported by Peter Krefting.)
63 Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
64 directory /a/b already exists.
66 Remove zoneinfo2tdf.pl, as it was unused and triggered false
67 malware alarms on some email servers.
70 Release 2022b - 2022-08-10 15:38:32 -0700
73 Chile's DST is delayed by a week in September 2022.
74 Iran no longer observes DST after 2022.
75 Rename Europe/Kiev to Europe/Kyiv.
77 Vanguard form now uses %z.
78 Finish moving duplicate-since-1970 zones to 'backzone'.
79 New build option PACKRATLIST
80 New tailored_tarballs target, replacing rearguard_tarballs
82 Changes to future timestamps
84 Chile's 2022 DST start is delayed from September 4 to September 11.
85 (Thanks to Juan Correa.)
87 Iran plans to stop observing DST permanently, after it falls back
88 on 2022-09-21. (Thanks to Ali Mirjamali.)
90 Changes to past timestamps
92 Finish moving to 'backzone' the location-based zones whose
93 timestamps since 1970 are duplicates; adjust links accordingly.
94 This change ordinarily affects only pre-1970 timestamps, and with
95 the new PACKRATLIST option it does not affect any timestamps.
96 In this round the affected zones are Antarctica/Vostok,
97 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
98 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
99 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
100 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
101 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
102 Pacific/Wake and Pacific/Wallis, and the affected links are
103 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
104 Pacific/Truk, and Pacific/Yap.
106 From fall 1994 through fall 1995, Shanks wrote that Crimea's
107 DST transitions were at 02:00 standard time, not at 00:00.
108 (Thanks to Michael Deckers.)
110 Iran adopted standard time in 1935, not 1946. In 1977 it observed
111 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
112 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
113 transition was on 05-27, not 03-21.
114 (Thanks to Roozbeh Pournader and Francis Santoni.)
116 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
117 considered DST, not standard time. Santiago and environs had moved
118 their clocks back to rejoin the rest of mainland Chile; put this
119 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
121 Some old, small clock transitions have been removed, as people at
122 the time did not change their clocks. This affects Asia/Hong_Kong
123 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
127 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
128 English now. Spelling of other names in Ukraine has not yet
129 demonstrably changed in common English practice so for now these
130 names retain old spellings, as in other countries (e.g.,
131 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
135 zic has a new option '-R @N' to output explicit transitions < N.
136 (Need suggested by Almaz Mingaleev.)
138 'zic -r @N' no longer outputs bad data when N < first transition.
139 (Problem introduced in 2021d and reported by Peter Krefting.)
141 zic now checks its input for NUL bytes and unterminated lines, and
142 now supports input line lengths up to 2048 (not 512) bytes.
144 gmtime and related code now use the abbreviation "UTC" not "GMT".
145 POSIX is being revised to require this.
147 When tzset and related functions set vestigial static variables
148 like tzname, they now prefer specified timestamps to unspecified ones.
149 (Problem reported by Almaz Mingaleev.)
151 zic no longer complains "can't determine time zone abbreviation to
152 use just after until time" when a transition to a new standard
153 time occurs simultaneously with the first DST fallback transition.
155 Changes to build procedure
157 Source data in vanguard form now uses the %z notation, introduced
158 in release 2015f. For example, for America/Sao_Paulo vanguard
159 form contains the zone continuation line "-3:00 Brazil %z", which
160 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
161 used in main and rearguard forms. The plan is for the main form
162 to use %z eventually; in the meantime maintainers of zi parsers
163 are encouraged to test the parsers on vanguard.zi.
165 The Makefile has a new PACKRATLIST option to select a subset of
166 'backzone'. For example, 'make PACKRATDATA=backzone
167 PACKRATLIST=zone.tab' now generates TZif files identical to those
168 of the global-tz project.
170 The Makefile has a new tailored_tarballs target for generating
171 special-purpose tarballs. It generalizes and replaces the
172 rearguard_tarballs target and related targets and macros, which
175 'make install' now defaults LOCALTIME to Factory not GMT,
176 which means the default abbreviation is now "-00" not "GMT".
178 Remove the posix_packrat target, marked obsolescent in 2016a.
181 Release 2022a - 2022-03-15 23:02:01 -0700
184 Palestine will spring forward on 2022-03-27, not -03-26.
185 zdump -v now outputs better failure indications.
186 Bug fixes for code that reads corrupted TZif data.
188 Changes to future timestamps
190 Palestine will spring forward on 2022-03-27, not 2022-03-26.
191 (Thanks to Heba Hamad.) Predict future transitions for first
192 Sunday >= March 25. Additionally, predict fallbacks to be the first
193 Friday on or after October 23, not October's last Friday, to be more
194 consistent with recent practice. The first differing fallback
195 prediction is on 2025-10-24, not 2025-10-31.
197 Changes to past timestamps
199 From 1992 through spring 1996, Ukraine's DST transitions were at
200 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
202 Chile's Santiago Mean Time and its LMT precursor have been adjusted
203 eastward by 1 second to align with past and present law.
205 Changes to commentary
207 Add several references for Chile's 1946/1947 transitions, some of
208 which only affected portions of the country.
212 Fix bug when mktime gets confused by truncated TZif files with
213 unspecified local time. (Problem reported by Almaz Mingaleev.)
215 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
216 (Problem reported by Christos Zoulas.)
218 When reading a version 2 or later TZif file, the TZif reader now
219 validates the version 1 header and data block only enough to skip
220 over them, as recommended by RFC 8536 section 4. Also, the TZif
221 reader no longer mistakenly attempts to parse a version 1 TZIf
222 file header as a TZ string.
224 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
225 when local time and UT cannot be determined for a timestamp.
227 Changes to build procedure
229 Distribution tarballs now use standard POSIX.1-1988 ustar format
230 instead of GNU format. Although the formats are almost identical
231 for these tarballs, ustar headers' magic fields contain "ustar"
232 instead of "ustar ", and their version fields contain "00" instead
233 of " ". The two formats are planned to diverge more significantly
234 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
235 format becomes obsolete and the tarballs switch to pax format, an
236 extension of ustar. For details about these formats, please see
237 "pax - portable archive interchange", IEEE Std 1003.1-2017,
238 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
241 Release 2021e - 2021-10-21 18:41:00 -0700
243 Changes to future timestamps
245 Palestine will fall back 10-29 (not 10-30) at 01:00.
246 (Thanks to P Chan and Heba Hemad.)
249 Release 2021d - 2021-10-15 13:48:18 -0700
252 Fiji suspends DST for the 2021/2022 season.
253 'zic -r' marks unspecified timestamps with "-00".
255 Changes to future timestamps
257 Fiji will suspend observance of DST for the 2021/2022 season.
258 Assume for now that it will return next year. (Thanks to Jashneel
263 'zic -r' now uses "-00" time zone abbreviations for intervals
264 with UT offsets that are unspecified due to -r truncation.
265 This implements a change in draft Internet RFC 8536bis.
268 Release 2021c - 2021-10-01 14:21:49 -0700
271 Revert most 2021b changes to 'backward'.
272 Fix 'zic -b fat' bug in pre-1970 32-bit data.
273 Fix two Link line typos.
274 Distribute SECURITY file.
276 This release is intended as a bugfix release, to fix compatibility
277 problems and typos reported since 2021b was released.
279 Changes to Link directives
281 Revert almost all of 2021b's changes to the 'backward' file,
282 by moving Link directives back to where they were in 2021a.
283 Although 'zic' doesn't care which source file contains a Link
284 directive, some downstream uses ran into trouble with the move.
285 (Problem reported by Stephen Colebourne for Joda-Time.)
287 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
288 (problem reported by Chris Walton).
290 Fix 'backzone' typo that linked America/Virgin to the wrong
291 location (problem reported by Michael Deckers).
295 Fix a bug in 'zic -b fat' that caused old timestamps to be
296 mishandled in 32-bit-only readers (problem reported by Daniel
299 Changes to documentation
301 Distribute the SECURITY file (problem reported by Andreas Radke).
304 Release 2021b - 2021-09-24 16:23:00 -0700
307 Jordan now starts DST on February's last Thursday.
308 Samoa no longer observes DST.
309 Merge more location-based Zones whose timestamps agree since 1970.
310 Move some backward-compatibility links to 'backward'.
311 Rename Pacific/Enderbury to Pacific/Kanton.
312 Correct many pre-1993 transitions in Malawi, Portugal, etc.
313 zic now creates each output file or link atomically.
314 zic -L no longer omits the POSIX TZ string in its output.
315 zic fixes for truncation and leap second table expiration.
316 zic now follows POSIX for TZ strings using all-year DST.
317 Fix some localtime crashes and bugs in obscure cases.
318 zdump -v now outputs more-useful boundary cases.
319 tzfile.5 better matches a draft successor to RFC 8536.
322 This release is prompted by recent announcements by Jordan and Samoa.
323 It incorporates many other changes that had accumulated since 2021a.
324 However, it omits most proposed changes that merged all Zones
325 agreeing since 1970, as concerns were raised about doing too many of
326 these changes at once. It does keeps some of these changes in the
327 interest of making tzdb more equitable one step at a time; see
328 "Merge more location-based Zones" below.
330 Changes to future timestamps
332 Jordan now starts DST on February's last Thursday.
333 (Thanks to Steffen Thorsen.)
335 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
339 Rename Pacific/Enderbury to Pacific/Kanton. When we added
340 Enderbury in 1993, we did not know that it is uninhabited and that
341 Kanton (population two dozen) is the only inhabited location in
342 that timezone. The old name is now a backward-compatibility link.
344 Changes to past timestamps
346 Correct many pre-1993 transitions, fixing entries originally
347 derived from Shanks, Whitman, and Mundell. The fixes include:
348 - Barbados: standard time was introduced in 1911, not 1932; and
349 DST was observed in 1942-1944
350 - Cook Islands: In 1899 they switched from east to west of GMT,
351 celebrating Christmas for two days. They (and Niue) switched
352 to standard time in 1952, not 1901.
353 - Guyana: corrected LMT for Georgetown; the introduction of
354 standard time in 1911, not 1915; and corrections to 1975 and
356 - Kanton: uninhabited before 1937-08-31
357 - Niue: only observed -11:20 from 1952 through 1964, then went to
358 -11 instead of -11:30
359 - Portugal: DST was observed in 1950
360 - Tonga: corrected LMT; the introduction of standard time in 1945,
361 not 1901; and corrections to the transition from +12:20 to +13
363 Additional fixes to entries in the 'backzone' file include:
364 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
365 - The Gambia: 1933 and 1942 transitions
366 - Malawi: several 1911 through 1925 transitions
367 - Sierra Leone: several 1913 through 1941 transitions, and DST
368 was NOT observed in 1957 through 1962
369 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
372 Merge more location-based Zones whose timestamps agree since 1970,
373 as pre-1970 timestamps are out of scope. This is part of a
374 process that has been ongoing since 2013. This does not affect
375 post-1970 timestamps, and timezone historians who build with 'make
376 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
377 When merging, keep the most-populous location's data, and move
378 data for other locations to 'backzone' with a backward
379 link in 'backward'. For example, move America/Creston data to
380 'backzone' with a link in 'backward' from America/Phoenix because
381 the two timezones' timestamps agree since 1970; this change
382 affects some pre-1968 timestamps in America/Creston because
383 Creston and Phoenix disagreed before 1968. The affected Zones
384 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
385 America/Creston, America/Curacao, America/Nassau,
386 America/Port_of_Spain, Antarctica/DumontDUrville, and
389 Changes to maintenance procedure
391 The new file SECURITY covers how to report security-related bugs.
393 Several backward-compatibility links have been moved to the
394 'backward' file. These links, which range from Africa/Addis_Ababa
395 to Pacific/Saipan, are only for compatibility with now-obsolete
396 guidelines suggesting an entry for every ISO 3166 code.
397 The intercontinental convenience links Asia/Istanbul and
398 Europe/Nicosia have also been moved to 'backward'.
402 zic now creates each output file or link atomically,
403 possibly by creating a temporary file and then renaming it.
404 This avoids races where a TZ setting would temporarily stop
405 working while zic was installing a replacement file or link.
407 zic -L no longer omits the POSIX TZ string in its output.
408 Starting with 2020a, zic -L truncated its output according to the
409 "Expires" directive or "#expires" comment in the leapseconds file.
410 The resulting TZif files omitted daylight saving transitions after
411 the leap second table expired, which led to far less-accurate
412 predictions of times after the expiry. Although future timestamps
413 cannot be converted accurately in the presence of leap seconds, it
414 is more accurate to convert near-future timestamps with a few
415 seconds error than with an hour error, so zic -L no longer
416 truncates output in this way.
418 Instead, when zic -L is given the "Expires" directive, it now
419 outputs the expiration by appending a no-change entry to the leap
420 second table. Although this should work well with most TZif
421 readers, it does not conform to Internet RFC 8536 and some pickier
422 clients (including tzdb 2017c through 2021a) reject it, so
423 "Expires" directives are currently disabled by default. To enable
424 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
425 this new feature it is marked with a new TZif version number 4,
426 a format intended to be documented in a successor to RFC 8536.
428 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
429 that omits leap second information for the range LO..B when LO
430 falls between two leap seconds A and B. Instead, it generates a
431 TZif version 4 file that represents the previously-missing
434 The TZif reader now allows the leap second table to begin with a
435 correction other than -1 or +1, and to contain adjacent
436 transitions with equal corrections. This supports TZif version 4.
438 The TZif reader now lets leap seconds occur less than 28 days
439 apart. This supports possible future TZif extensions.
441 Fix bug that caused 'localtime' etc. to crash when TZ was
442 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
443 not conform to POSIX but does conform to Internet RFC 8536.
445 Fix another bug that caused 'localtime' etc. to crash when TZ was
446 set to a POSIX-conforming but unusual TZ string like
447 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
449 Fix yet another bug that caused 'localtime' etc. to mishandle slim
450 TZif files containing leap seconds after the last explicit
451 transition in the table, or when handling far-future timestamps
452 in slim TZif files lacking leap seconds.
454 Fix localtime misbehavior involving positive leap seconds.
455 This change affects only behavior for "right" system time,
456 which contains leap seconds, and only if the UT offset is
457 not a multiple of 60 seconds when a positive leap second occurs.
458 (No such timezone exists in tzdb, luckily.) Without the fix,
459 the timestamp was ambiguous during a positive leap second.
460 With the fix, any seconds occurring after a positive leap second
461 and within the same localtime minute are counted through 60, not
462 through 59; their UT offset (tm_gmtoff) is the same as before.
463 Here is how the fix affects timestamps in a timezone with UT
464 offset +01:23:45 (5025 seconds) and with a positive leap second at
465 1972-06-30 23:59:60 UTC (78796800):
467 time_t without the fix with the fix
468 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
469 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
471 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
472 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
474 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
475 civil time changes a few seconds before time_t wraps around, when
476 leap seconds are enabled.
478 Fix bug in zic -r; in some cases, the dummy time type after the
479 last time transition disagreed with the TZ string, contrary to
480 Internet RFC 8563 section 3.3.
482 Fix a bug with 'zic -r @X' when X is a negative leap second that
483 has a nonnegative correction. Without the fix, the output file
484 was truncated so that X appeared to be a positive leap second.
485 Fix a similar, even-less-likely bug when truncating at a positive
486 leap second that has a nonpositive correction.
488 zic -r now reports an error if given rolling leap seconds, as this
489 usage has never generally worked and is evidently unused.
491 zic now generates a POSIX-conforming TZ string for TZif files
492 where all-year DST is predicted for the indefinite future.
493 For example, for all-year Eastern Daylight Time, zic now generates
494 "XXX3EDT4,0/0,J365/23" where it previously generated
495 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
496 noting the possibility of POSIX conformance.)
498 zic.c no longer requires sys/wait.h (thanks to spazmodius for
499 noting it wasn't needed).
501 When reading slim TZif files, zdump no longer mishandles leap
502 seconds on the rare platforms where time_t counts leap seconds,
503 fixing a bug introduced in 2014g.
505 zdump -v now outputs timestamps at boundaries of what localtime
506 and gmtime can represent, instead of the less-useful timestamps
507 one day after the minimum and one day before the maximum.
508 (Thanks to Arthur David Olson for prototype code, and to Manuela
509 Friedrich for debugging help.)
511 zdump's -c and -t options are now consistently inclusive for the
512 lower time bound and exclusive for the upper. Formerly they were
513 inconsistent. (Confusion noted by Martin Burnicki.)
515 Changes to build procedure
517 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
518 non-POSIX hosts where malloc doesn't set errno.
519 (Problem reported by Jan Engelhardt.)
521 Changes to documentation
523 tzfile.5 better matches a draft successor to RFC 8536
524 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
527 Release 2021a - 2021-01-24 10:54:57 -0800
529 Changes to future timestamps
531 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
532 (Thanks to Steffen Thorsen.)
535 Release 2020f - 2020-12-29 00:17:46 -0800
537 Change to build procedure
539 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
540 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
543 Release 2020e - 2020-12-22 15:14:34 -0800
546 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
548 Changes to future timestamps
550 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
551 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
553 Changes to past timestamps
555 Correct many pre-1986 transitions, fixing entries originally
556 derived from Shanks. The fixes include:
557 - Australia: several 1917 through 1971 transitions
558 - The Bahamas: several 1941 through 1945 transitions
559 - Bermuda: several 1917 through 1956 transitions
560 - Belize: several 1942 through 1968 transitions
561 - Ghana: several 1915 through 1956 transitions
562 - Israel and Palestine: several 1940 through 1985 transitions
563 - Kenya and adjacent: several 1908 through 1960 transitions
564 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
565 through 1919 transitions
566 - Seychelles: the introduction of standard time in 1907, not 1906
567 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
570 Because of the Australia change, Australia/Currie (King Island) is
571 no longer needed, as it is identical to Australia/Hobart for all
572 timestamps since 1970 and was therefore created by mistake.
573 Australia/Currie has been moved to the 'backward' file and its
574 corrected data moved to the 'backzone' file.
576 Changes to past time zone abbreviations and DST flags
578 To better match legislation in Turks and Caicos, the 2015 shift to
579 year-round observance of -04 is now modeled as AST throughout before
580 returning to Eastern Time with US DST in 2018, rather than as
581 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
583 Changes to documentation
585 The zic man page now documents zic's coalescing of transitions
586 when a zone falls back just before DST springs forward.
589 Release 2020d - 2020-10-21 11:24:13 -0700
592 Palestine ends DST earlier than predicted, on 2020-10-24.
594 Changes to past and future timestamps
596 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
597 as previously predicted (thanks to Sharef Mustafa.) Its
598 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
599 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
600 its spring 2020 transition was on March 28 at 00:00, not March 27
601 (thanks to Pierre Cashon.) This affects Asia/Gaza and
602 Asia/Hebron. Assume future spring and fall transitions will be on
603 the Saturday preceding the last Sunday of March and October,
607 Release 2020c - 2020-10-16 11:15:53 -0700
610 Fiji starts DST later than usual, on 2020-12-20.
612 Changes to future timestamps
614 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
615 previously predicted. DST will still end on 2021-01-17.
616 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
617 the later-than-usual start date is a one-time departure from the
620 Changes to build procedure
622 Rearguard tarballs now contain an empty file pacificnew.
623 Some older downstream software expects this file to exist.
624 (Problem reported by Mike Cullinan.)
627 Release 2020b - 2020-10-06 18:35:04 -0700
630 Revised predictions for Morocco's changes starting in 2023.
631 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
632 Macquarie Island has stayed in sync with Tasmania since 2011.
633 Casey, Antarctica is at +08 in winter and +11 in summer.
634 zic no longer supports -y, nor the TYPE field of Rules.
636 Changes to future timestamps
638 Morocco's spring-forward after Ramadan is now predicted to occur
639 no sooner than two days after Ramadan, instead of one day.
640 (Thanks to Milamber.) The first altered prediction is for 2023,
641 now predicted to spring-forward on April 30 instead of April 23.
643 Changes to past and future timestamps
645 Casey Station, Antarctica has been using +08 in winter and +11 in
646 summer since 2018. The most recent transition from +08 to +11 was
647 2020-10-04 00:01. Also, Macquarie Island has been staying in
648 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
650 Changes to past and future time zone abbreviations and DST flags
652 Canada's Yukon, represented by America/Whitehorse and
653 America/Dawson, changes its time zone rules from -08/-07 to
654 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
655 This change affects only the time zone abbreviation (MST vs PDT)
656 and daylight saving flag for the period between the two dates.
657 (Thanks to Andrew G. Smith.)
659 Changes to past timestamps
661 Correct several transitions for Hungary for 1918/1983.
662 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
663 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
664 time was on 11-01, not 10-01 (thanks to Michael Deckers).
666 The 1891 French transition was on March 16, not March 15. The
667 1911-03-11 French transition was at midnight, not a minute later.
668 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
669 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
673 Support for zic's long-obsolete '-y YEARISTYPE' option has been
674 removed and, with it, so has support for the TYPE field in Rule
675 lines, which is now reserved for compatibility with earlier zic.
676 These features were previously deprecated in release 2015f.
677 (Thanks to Tim Parenti.)
679 zic now defaults to '-b slim' instead of to '-b fat'.
681 zic's new '-l -' and '-p -' options uninstall any existing
682 localtime and posixrules files, respectively.
684 The undocumented and ineffective tzsetwall function has been
687 Changes to build procedure
689 The Makefile now defaults POSIXRULES to '-', so the posixrules
690 feature (obsolete as of 2019b) is no longer installed by default.
692 Changes to documentation and commentary
694 The long-obsolete files pacificnew, systemv, and yearistype.sh have
695 been removed from the distribution. (Thanks to Tim Parenti.)
698 Release 2020a - 2020-04-23 16:03:47 -0700
701 Morocco springs forward on 2020-05-31, not 2020-05-24.
702 Canada's Yukon advanced to -07 year-round on 2020-03-08.
703 America/Nuuk renamed from America/Godthab.
704 zic now supports expiration dates for leap second lists.
706 Changes to future timestamps
708 Morocco's second spring-forward transition in 2020 will be May 31,
709 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
710 Adjust future-year predictions to use the first Sunday after the
711 day after Ramadan, not the first Sunday after Ramadan.
713 Canada's Yukon, represented by America/Whitehorse and
714 America/Dawson, advanced to -07 year-round, beginning with its
715 spring-forward transition on 2020-03-08, and will not fall back on
716 2020-11-01. Although a government press release calls this
717 "permanent Pacific Daylight Saving Time", we prefer MST for
718 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
719 (Thanks to Tim Parenti.)
721 Changes to past timestamps
723 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
725 Changes to timezone identifiers
727 To reflect current usage in English better, America/Godthab has
728 been renamed to America/Nuuk. A backwards-compatibility link
729 remains for the old name.
733 localtime.c no longer mishandles timestamps after the last
734 transition in a TZif file with leap seconds and with daylight
735 saving time transitions projected into the indefinite future.
736 For example, with TZ='America/Los_Angeles' with leap seconds,
737 zdump formerly reported a DST transition on 2038-03-14
738 from 01:59:32.999... to 02:59:33 instead of the correct transition
739 from 01:59:59.999... to 03:00:00.
741 zic -L now supports an Expires line in the leapseconds file, and
742 truncates the TZif output accordingly. This propagates leap
743 second expiration information into the TZif file, and avoids the
744 abovementioned localtime.c bug as well as similar bugs present in
745 many client implementations. If no Expires line is present, zic
746 -L instead truncates the TZif output based on the #expires comment
747 present in leapseconds files distributed by tzdb 2018f and later;
748 however, this usage is obsolescent. For now, the distributed
749 leapseconds file has an Expires line that is commented out, so
750 that the file can be fed to older versions of zic which ignore the
751 commented-out line. Future tzdb distributions are planned to
752 contain a leapseconds file with an Expires line.
754 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
755 set to 1 if the system library supports the feature, and 2 if not.
756 As before, these macros are nonzero if tzcode should support the
757 feature, zero otherwise.
759 The configuration macro ALTZONE now has the same values with the
760 same meaning as HAVE_TZNAME and USG_COMPAT.
762 The code's defense against CRLF in leap-seconds.list is now
763 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
765 Although the undocumented tzsetwall function is not changed in
766 this release, it is now deprecated in preparation for removal in
767 future releases. Due to POSIX requirements, tzsetwall has not
768 worked for some time. Any code that uses it should instead use
769 tzalloc(NULL) or, if portability trumps thread-safety, should
770 unset the TZ environment variable.
772 Changes to commentary
774 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
775 following America/Halifax, and comments about Yukon's "south" and
776 "north" have been corrected to say "east" and "west". (Thanks to
780 Release 2019c - 2019-09-11 08:59:48 -0700
783 Fiji observes DST from 2019-11-10 to 2020-01-12.
784 Norfolk Island starts observing Australian-style DST.
786 Changes to future timestamps
788 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
789 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
790 Adjust future guesses accordingly.
792 Norfolk Island will observe Australian-style DST starting in
793 spring 2019. The first transition is on 2019-10-06. (Thanks to
794 Kyle Czech and Michael Deckers.)
796 Changes to past timestamps
798 Many corrections to time in Turkey from 1940 through 1985.
799 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
801 The Norfolk Island 1975-03-02 transition was at 02:00 standard
802 time, not 02:00 DST. (Thanks to Michael Deckers.)
804 South Korea observed DST from 1948 through 1951. Although this
805 info was supposed to appear in release 2014j, a typo inadvertently
806 suppressed the change. (Thanks to Alois Treindl.)
808 Detroit observed DST in 1967 and 1968 following the US DST rules,
809 except that its 1967 DST began on June 14 at 00:01. (Thanks to
810 Alois Treindl for pointing out that the old data entries were
813 Fix several errors in pre-1970 transitions in Perry County, IN.
814 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
816 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
817 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
818 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
819 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
820 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
821 Königsberg switched to +03 on 04-07 not 01-01.
823 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
824 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
825 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
827 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
828 (Thanks to Michael Deckers.)
830 Changes to past time zone abbreviations and DST flags
832 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
833 is now flagged as DST and is abbreviated HKWT not HKT.
837 leapseconds.awk now relies only on its input data, rather than
838 also relying on its comments. (Inspired by code from Dennis
839 Ferguson and Chris Woodbury.)
841 The code now defends against CRLFs in leap-seconds.list.
842 (Thanks to Brian Inglis and Chris Woodbury.)
844 Changes to documentation and commentary
846 theory.html discusses leap seconds. (Thanks to Steve Summit.)
848 Nashville's newspapers dueled about the time of day in the 1950s.
849 (Thanks to John Seigenthaler.)
851 Liechtenstein observed Swiss DST in 1941/2.
852 (Thanks to Alois Treindl.)
855 Release 2019b - 2019-07-01 00:09:53 -0700
858 Brazil no longer observes DST.
859 'zic -b slim' outputs smaller TZif files; please try it out.
860 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
862 Changes to future timestamps
864 Brazil has canceled DST and will stay on standard time indefinitely.
865 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
868 Predictions for Morocco now go through 2087 instead of 2037, to
869 work around a problem on newlib when using TZif files output by
870 zic 2019a or earlier. (Problem reported by David Gauchard.)
872 Changes to past and future timestamps
874 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
875 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
876 future transitions to be March's last Friday at 00:00.
878 Changes to past timestamps
880 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
881 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
882 not 09-15 at 00:00. In 1946 its spring-forward transition was on
883 04-21 at 00:00, not the previous day at 03:30. From 1946 through
884 1952 its fall-back transitions occurred at 04:30, not at 03:30.
885 In 1947 its fall-back transition was on 11-30, not 12-30.
888 Changes to past time zone abbreviations
890 Italy's 1866 transition to Rome Mean Time was on December 12, not
891 September 22. This affects only the time zone abbreviation for
892 Europe/Rome between those dates. (Thanks to Stephen Trainor and
895 Changes affecting metadata only
897 Add info about the Crimea situation in zone1970.tab and zone.tab.
898 (Problem reported by Serhii Demediuk.)
902 zic's new -b option supports a way to control data bloat and to
903 test for year-2038 bugs in software that reads TZif files.
904 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
905 for example, changing from fat to slim shrinks the Europe/London
906 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
907 files represent the same set of timestamps and use the same TZif
908 format as documented in tzfile(5) and in Internet RFC 8536.
909 Fat format attempts to work around bugs or incompatibilities in
910 older software, notably software that mishandles 64-bit TZif data
911 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
912 Slim format is more efficient and does not work around 64-bit bugs
913 or obsolete TZ strings. Currently zic defaults to fat format
914 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
915 out-of-the-box default is intended to change in future releases
916 as the buggy software often mishandles timestamps anyway.
918 zic no longer treats a set of rules ending in 2037 specially.
919 Previously, zic assumed that such a ruleset meant that future
920 timestamps could not be predicted, and therefore omitted a
921 POSIX-like TZ string in the TZif output. The old behavior is no
922 longer needed for current tzdata, and caused problems with newlib
923 when used with older tzdata (reported by David Gauchard).
925 zic no longer generates some artifact transitions. For example,
926 Europe/London no longer has a no-op transition in January 1996.
928 Changes to build procedure
930 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
933 Changes to documentation and commentary
935 The Makefile now documents the POSIXRULES macro as being obsolete,
936 and similarly, zic's -p POSIXRULES option is now documented as
937 being obsolete. Although the POSIXRULES feature still exists and
938 works as before, in practice it is rarely used for its intended
939 purpose, and it does not work either in the default reference
940 implementation (for timestamps after 2037) or in common
941 implementations such as GNU/Linux (for contemporary timestamps).
942 Since POSIXRULES was designed primarily as a temporary transition
943 facility for System V platforms that died off decades ago, it is
944 being decommissioned rather than institutionalized.
946 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
949 Release 2019a - 2019-03-25 22:01:33 -0700
952 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
953 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
955 Changes to past and future timestamps
957 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
958 previously predicted. Adjust our prediction by guessing that spring
959 transitions will be between 24 and 30 March, which matches recent practice
960 since 2016. (Thanks to Even Scharning and Tim Parenti.)
962 Metlakatla ended its observance of Pacific standard time,
963 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
964 Stanley and Tim Parenti.)
966 Changes to past timestamps
968 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
969 (Thanks to Alois Treindl and Isaac Starkman.)
971 Changes to time zone abbreviations
973 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
974 of being a separate zone that generates the abbreviation "UCT",
975 which nowadays is typically a typo. (Problem reported by Isiah
980 zic now has an -r option to limit the time range of output data.
981 For example, 'zic -r @1000000000' limits the output data to
982 timestamps starting 1000000000 seconds after the Epoch.
983 This helps shrink output size and can be useful for applications
984 not needing the full timestamp history, such as TZDIST truncation;
985 see Internet RFC 8536 section 5.1. (Inspired by a feature request
986 from Christopher Wong, helped along by bug reports from Wong and
989 Changes to documentation
991 Mention Internet RFC 8536 (February 2019), which documents TZif.
993 tz-link.html now cites tzdata-meta
994 <https://tzdata-meta.timtimeonline.com/>.
997 Release 2018i - 2018-12-30 11:05:43 -0800
1000 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
1002 Changes to future timestamps
1004 Due to a change in government, São Tomé and Príncipe switches back
1005 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
1006 Nasardinov and Michael Deckers.)
1009 Release 2018h - 2018-12-23 17:59:32 -0800
1012 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
1013 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
1014 Metlakatla, Alaska observes PST this winter only.
1015 Guess Morocco will continue to adjust clocks around Ramadan.
1016 Add predictions for Iran from 2038 through 2090.
1018 Changes to future timestamps
1020 Guess that Morocco will continue to fall back just before and
1021 spring forward just after Ramadan, the practice since 2012.
1022 (Thanks to Maamar Abdelkader.) This means Morocco will observe
1023 negative DST during Ramadan in main and vanguard formats, and in
1024 rearguard format it stays in the +00 timezone and observes
1025 ordinary DST in all months other than Ramadan. As before, extend
1026 this guesswork to the year 2037. As a consequence, Morocco is
1027 scheduled to observe three DST transitions in some Gregorian years
1028 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
1031 The table of exact transitions for Iranian DST has been extended.
1032 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
1033 It now cuts off before 2091 as there is doubt about how the Persian
1034 calendar will treat 2091. This change predicts DST transitions in
1035 2038-9, 2042-3, and 2046-7 to occur one day later than previously
1036 predicted. As before, post-cutoff transitions are approximated.
1038 Changes to past and future timestamps
1040 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
1041 +05 on 2018-12-21. This is a zone split as Qostanay (aka
1042 Kostanay) did not switch, so create a zone Asia/Qostanay.
1044 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
1045 It did not change clocks that day and remains on -08 this winter.
1046 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
1047 rules next spring, so this change affects only timestamps
1048 from 2018-11-04 through 2019-03-10.
1050 Change to past timestamps
1052 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
1053 not 00:00. I transcribed the time incorrectly from Shanks.
1054 (Thanks to Phake Nick.)
1056 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
1057 (Thanks to Phake Nick.)
1059 Guam observed DST irregularly from 1959 through 1977.
1060 (Thanks to Phake Nick.)
1062 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
1063 10-01 changed standard time to +08:30 (not +08). Its transition
1064 back to +08 after WWII was on 1945-09-15, not the previous day.
1065 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
1066 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1067 its 1952 fallback was on 11-02 (not 10-25).
1069 This release contains many changes to timestamps before 1946 due
1070 to Japanese possession or occupation of Pacific/Chuuk,
1071 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1072 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1073 (Thanks to Phake Nick.)
1075 Assume that the Spanish East Indies was like the Philippines and
1076 observed American time until the end of 1844. This affects
1077 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1079 Changes to past tm_isdst flags
1081 For the recent Morocco change, the tm_isdst flag should be 1 from
1082 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1083 Give a URL to the official decree. (Thanks to Matt Johnson.)
1086 Release 2018g - 2018-10-26 22:22:45 -0700
1089 Morocco switches to permanent +01 on 2018-10-28.
1091 Changes to future timestamps
1093 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1094 so its clocks will not fall back as previously scheduled.
1095 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1099 When generating TZif files with leap seconds, zic no longer uses a
1100 format that trips up older 32-bit clients, fixing a bug introduced
1101 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1102 for QTBUG-53071 now also works for TZif files with leap seconds.
1104 The translator to rearguard format now rewrites the line
1105 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1106 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1107 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1108 and earlier. (Reported by Christos Zoulas.)
1110 Changes to past time zone abbreviations
1112 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1113 This reverts to 2011h, as the abbreviation change in 2011i was
1116 Changes to documentation
1118 tzfile.5 has new sections on interoperability issues.
1121 Release 2018f - 2018-10-18 00:14:18 -0700
1124 Volgograd moves from +03 to +04 on 2018-10-28.
1125 Fiji ends DST 2019-01-13, not 2019-01-20.
1126 Most of Chile changes DST dates, effective 2019-04-06.
1128 Changes to future timestamps
1130 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1131 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1133 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1134 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1137 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1138 time, and resume DST on the first Saturday in September at 24:00 mainland
1139 time. The changes are effective from 2019-04-06, and do not affect the
1140 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1141 and Tim Parenti.) Adjust future predictions accordingly.
1143 Changes to past timestamps
1145 The 2018-05-05 North Korea 30-minute time zone change took place
1146 at 23:30 the previous day, not at 00:00 that day.
1148 China's 1988 spring-forward transition was on April 17, not
1149 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1152 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1153 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1154 temporarily switched to +09/+10 during World War II. Macau
1155 observed DST in 1942/79, not 1961/80, and there were several
1156 errors for transition times and dates. (Thanks to P Chan.)
1158 The 1948-1951 fallback transitions in Japan were at 25:00 on
1159 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1160 zic turns this into 01:00 on the day after September's second
1161 Saturday, which is the best that POSIX or C platforms can do.
1163 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1164 paper by Li Yu, replacing more-questionable data from Shanks.
1166 Changes to time zone abbreviations
1168 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1172 zic now always generates TZif files where time type 0 is used for
1173 timestamps before the first transition. This simplifies the
1174 reading of TZif files and should not affect behavior of existing
1175 TZif readers because the same set of time types is used; only
1176 their internal indexes may have changed. This affects only the
1177 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1178 EET, which previously used nonzero types for these timestamps.
1180 Because of the type 0 change, zic no longer outputs a dummy
1181 transition at time -2**59 (before the Big Bang), as clients should
1182 no longer need this to handle historical timestamps correctly.
1183 This reverts a change introduced in 2013d and shrinks most TZif
1184 files by a few bytes.
1186 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1187 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1188 occurs at 18:00 on the Saturday before the last Sunday in April.
1189 This behavior was documented in 2018a but the code did not
1190 entirely match the documentation.
1192 localtime.c no longer requires at least one time type in TZif
1193 files that lack transitions or have a POSIX-style TZ string. This
1194 future-proofs the code against possible future extensions to the
1195 format that would allow TZif files with POSIX-style TZ strings and
1196 without transitions or time types.
1198 A read-access subscript error in localtime.c has been fixed.
1199 It could occur only in TZif files with timecnt == 0, something that
1200 does not happen in practice now but could happen in future versions.
1202 localtime.c no longer ignores TZif POSIX-style TZ strings that
1203 specify only standard time. Instead, these TZ strings now
1204 override the default time type for timestamps after the last
1205 transition (or for all timestamps if there are no transitions),
1206 just as DST strings specifying DST have always done.
1208 leapseconds.awk now outputs "#updated" and "#expires" comments,
1209 and supports leap seconds at the ends of months other than June
1210 and December. (Inspired by suggestions from Chris Woodbury.)
1212 Changes to documentation
1214 New restrictions: A Rule name must start with a character that
1215 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1216 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1217 The latter restriction makes room for future extensions (a
1218 possibility noted by Tom Lane).
1220 tzfile.5 now documents what time types apply before the first and
1221 after the last transition, if any.
1223 Documentation now uses the spelling "timezone" for a TZ setting
1224 that determines timestamp history, and "time zone" for a
1225 geographic region currently sharing the same standard time.
1227 The name "TZif" is now used for the tz binary data format.
1229 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1230 (Thanks to Aldrin Martoq for the link.)
1232 Changes to build procedure
1234 New 'make' target 'rearguard_tarballs' to build the rearguard
1235 tarball only. This is a convenience on platforms that lack lzip
1236 if you want to build the rearguard tarball. (Problem reported by
1239 tzdata.zi is now more stable from release to release. (Problem
1240 noted by Tom Lane.) It is also a bit shorter.
1242 tzdata.zi now can contain comment lines documenting configuration
1243 information, such as which data format was selected, which input
1244 files were used, and how leap seconds are treated. (Problems
1245 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1246 are used these comment lines are absent, for backward
1247 compatibility. A redistributor intending to alter its copy of the
1248 files should also append "-LABEL" to the 'version' file's first
1249 line, where "LABEL" identifies the redistributor's change.
1252 Release 2018e - 2018-05-01 23:42:51 -0700
1256 North Korea switches back to +09 on 2018-05-05.
1257 The main format uses negative DST again, for Ireland etc.
1258 'make tarballs' now also builds a rearguard tarball.
1259 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1261 Changes to past and future timestamps
1263 North Korea switches back from +0830 to +09 on 2018-05-05.
1264 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1267 Bring back the negative-DST changes of 2018a, except be more
1268 compatible with data parsers that do not support negative DST.
1269 Also, this now affects historical timestamps in Namibia and the
1270 former Czechoslovakia, not just Ireland. The main format now uses
1271 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1272 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1273 does not affect UT offsets, only time zone abbreviations and the
1274 tm_isdst flag. Also, this does not affect rearguard or vanguard
1275 formats; effectively the main format now uses vanguard instead of
1276 rearguard format. Data parsers that do not support negative DST
1277 can still use data from the rearguard tarball described below.
1279 Changes to build procedure
1281 The command 'make tarballs' now also builds the tarball
1282 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1283 except that it uses rearguard format intended for trailing-edge
1286 Changes to data format and to code
1288 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1289 suffix, which specifies whether the adjusted time is standard time
1290 or daylight saving time. If no suffix is given, daylight saving
1291 time is used if and only if the SAVE column is nonzero; this is
1292 the longstanding behavior. Although this new feature is not used
1293 in tzdata, it could be used to specify the legal time in Namibia
1294 1994-2017, as opposed to the popular time (see below).
1296 Changes to past timestamps
1298 From 1994 through 2017 Namibia observed DST in winter, not summer.
1299 That is, it used negative DST, as Ireland still does. This change
1300 does not affect UTC offsets; it affects only the tm_isdst flag and
1301 the abbreviation used during summer, which is now CAT, not WAST.
1302 Although (as noted by Michael Deckers) summer and winter time were
1303 both simply called "standard time" in Namibian law, in common
1304 practice winter time was considered to be DST (as noted by Stephen
1305 Colebourne). The full effect of this change is only in vanguard
1306 and main format; in rearguard format, the tm_isdst flag is still
1307 zero in winter and nonzero in summer.
1309 In 1946/7 Czechoslovakia also observed negative DST in winter.
1310 The full effect of this change is only in vanguard and main
1311 formats; in rearguard format, it is modeled as plain GMT without
1312 daylight saving. Also, the dates of some 1944/5 DST transitions
1313 in Czechoslovakia have been changed.
1316 Release 2018d - 2018-03-22 07:05:46 -0700
1320 Palestine starts DST a week earlier in 2018.
1321 Add support for vanguard and rearguard data consumers.
1322 Add subsecond precision to source data format, though not to data.
1324 Changes to future timestamps
1326 In 2018, Palestine starts DST on March 24, not March 31.
1327 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1329 Changes to past and future timestamps
1331 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1332 at 04:00. (Thanks to Steffen Thorsen.)
1334 Changes to past timestamps
1336 Historical transitions for Uruguay, represented by
1337 America/Montevideo, have been updated per official legal documents,
1338 replacing previous data mainly originating from the inventions of
1339 Shanks & Pottenger. This has resulted in adjustments ranging from
1340 30 to 90 minutes in either direction over at least two dozen
1341 distinct periods ranging from one day to several years in length.
1342 A mere handful of pre-1991 transitions are unaffected; data since
1343 then has come from more reliable contemporaneous reporting. These
1344 changes affect various timestamps in 1920-1923, 1936, 1939,
1345 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1346 Additionally, Uruguay's pre-standard-time UT offset has been
1347 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1348 match the location of the Observatory of the National Meteorological
1349 Institute in Montevideo.
1350 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1352 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1353 (Thanks to Kerry Shetline.)
1355 Fix the 1912-01-01 transition for Portugal and its colonies.
1356 This transition was at 00:00 according to the new UT offset, not
1357 according to the old one. Also assume that Cape Verde switched on
1358 the same date as the rest, not in 1907. This affects
1359 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1360 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1361 (Thanks to Michael Deckers.)
1363 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1366 Changes to past time zone abbreviations
1368 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1369 is no clock change associated with the transition.
1371 Changes to build procedure
1373 The new DATAFORM macro in the Makefile lets the installer choose
1374 among three source data formats. The idea is to lessen downstream
1375 disruption when data formats are improved.
1377 * DATAFORM=vanguard installs from the latest, bleeding-edge
1378 format. DATAFORM=main (the default) installs from the format
1379 used in the 'africa' etc. files. DATAFORM=rearguard installs
1380 from a trailing-edge format. Eventually, elements of today's
1381 vanguard format should move to the main format, and similarly
1382 the main format's features should eventually move to the
1385 * In the current version, the main and rearguard formats are
1386 identical and match that of 2018c, so this change does not
1387 affect default behavior. The vanguard format currently contains
1388 one feature not in the main format: negative SAVE values. This
1389 improves support for Ireland, which uses Irish Standard Time
1390 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1391 supported negative SAVE values for decades, and this feature
1392 should move to the main format soon. However, it will not move
1393 to the rearguard format for quite some time because some
1394 downstream parsers do not support it.
1396 * The build procedure constructs three files vanguard.zi, main.zi,
1397 and rearguard.zi, one for each format. Although the files
1398 represent essentially the same data, they may have minor
1399 discrepancies that users are not likely to notice. The files
1400 are intended for downstream data consumers and are not
1401 installed. Zoneinfo parsers that do not support negative SAVE values
1402 should start using rearguard.zi, so that they will be unaffected
1403 when the negative-DST feature moves from vanguard to main.
1404 Bleeding-edge Zoneinfo parsers that support the new features
1405 already can use vanguard.zi; in this respect, current tzcode is
1408 The Makefile should now be safe for parallelized builds, and 'make
1409 -j to2050new.tzs' is now much faster on a multiprocessor host
1412 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1413 prepends TZDIR/ to file names that do not begin with '/'. This is
1414 not recommended for general use, due to its security implications.
1415 (From a suggestion by Manuela Friedrich.)
1419 zic now accepts subsecond precision in expressions like
1420 00:19:32.13, which is approximately the legal time of the
1421 Netherlands from 1835 to 1937. However, because it is
1422 questionable whether the few recorded uses of non-integer offsets
1423 had subsecond precision in practice, there are no plans for tzdata
1424 to use this feature. (Thanks to Steve Allen for pointing out
1425 the limitations of historical data in this area.)
1427 The code is a bit more portable to MS-Windows. Installers can
1428 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1429 reserve identifiers like 'localtime'. (Thanks to Manuela
1432 Changes to documentation and commentary
1434 theory.html now outlines tzdb's extensions to POSIX's model for
1435 civil time, and has a section "POSIX features no longer needed"
1436 that lists POSIX API components that are now vestigial.
1437 (From suggestions by Steve Summit.) It also better distinguishes
1438 time zones from tz regions. (From a suggestion by Guy Harris.)
1440 Commentary is now more consistent about using the phrase "daylight
1441 saving time", to match the C name tm_isdst. Daylight saving time
1442 need not occur in summer, and need not have a positive offset from
1445 Commentary about historical transitions in Uruguay has been expanded
1446 with links to many relevant legal documents.
1447 (Thanks to Tim Parenti.)
1449 Commentary now uses some non-ASCII characters with Unicode value
1450 less than U+0100, as they can be useful and should work even with
1451 older editors such as XEmacs.
1454 Release 2018c - 2018-01-22 23:00:44 -0800
1457 Revert Irish changes that relied on negative SAVE values.
1461 Revert the 2018a change to Europe/Dublin. As before, this change
1462 does not affect UT offsets or abbreviations; it affects only
1463 whether timestamps are considered to be standard time or
1464 daylight-saving time, as expressed in the tm_isdst flag of C's
1465 struct tm type. This reversion is intended to be a temporary
1466 workaround for problems discovered with downstream uses of
1467 releases 2018a and 2018b, which implemented Irish time by using
1468 negative SAVE values in the Eire rules of the 'europe' file.
1469 Although negative SAVE values have been part of tzcode for many
1470 years and are supported by many platforms, they were not
1471 documented before 2018a and ICU and OpenJDK do not currently
1472 support them. A mechanism to export data to platforms lacking
1473 support for negative DST is planned to be developed before the
1474 change is reapplied. (Problems reported by Deborah Goldsmith and
1475 Stephen Colebourne.)
1477 Changes to past timestamps
1479 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1480 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1482 Changes to build procedure
1484 The build procedure now works around mawk 1.3.3's lack of support
1485 for character class expressions. (Problem reported by Ohyama.)
1488 Release 2018b - 2018-01-17 23:24:48 -0800
1491 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1493 Changes to build procedure
1495 The distribution now contains the file 'pacificnew' again.
1496 This file was inadvertently omitted in the 2018a distribution.
1497 (Problem reported by Matias Fonzo.)
1500 Release 2018a - 2018-01-12 22:29:21 -0800
1503 São Tomé and Príncipe switched from +00 to +01.
1504 Brazil's DST will now start on November's first Sunday.
1505 Ireland's standard time is now in the summer, not the winter.
1506 Use Debian-style installation locations, instead of 4.3BSD-style.
1509 Changes to past and future timestamps
1511 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1512 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1514 Changes to future timestamps
1516 Starting in 2018 southern Brazil will begin DST on November's
1517 first Sunday instead of October's third Sunday. (Thanks to
1520 Changes to past timestamps
1522 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1523 been corrected. The 'backzone' and 'zone.tab' files did not agree
1524 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1527 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1528 BST instead of BOST, to be more consistent with the convention
1529 used for Latvian Summer Time (1918-9) and for British Summer Time.
1533 Change Europe/Dublin so that it observes Irish Standard Time (UT
1534 +01) in summer and GMT (as negative daylight-saving) in winter,
1535 instead of observing standard time (GMT) in winter and Irish
1536 Summer Time (UT +01) in summer. This change does not affect UT
1537 offsets or abbreviations; it affects only whether timestamps are
1538 considered to be standard time or daylight-saving time, as
1539 expressed in the tm_isdst flag of C's struct tm type.
1540 (Discrepancy noted by Derick Rethans.)
1542 Changes to build procedure
1544 The default installation locations have been changed to mostly
1545 match Debian circa 2017, instead of being designed as an add-on to
1546 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1547 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1548 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1549 locations more precisely. (This responds to suggestions from
1550 Brian Inglis and from Steve Summit.)
1552 The default installation procedure no longer creates the
1553 backward-compatibility link US/Pacific-New, which causes
1554 confusion during user setup (e.g., see Debian bug 815200).
1555 Use 'make BACKWARD="backward pacificnew"' to create the link
1556 anyway, for now. Eventually we plan to remove the link entirely.
1558 tzdata.zi now contains a version-number comment.
1559 (Suggested by Tom Lane.)
1561 The Makefile now quotes values like BACKWARD more carefully when
1562 passing them to the shell. (Problem reported by Zefram.)
1564 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1565 that have snprintf and use pre-C99 compilers. (Problem reported
1570 zic has a new option -t FILE that specifies the location of the
1571 file that determines local time when TZ is unset. The default for
1572 this location can be configured via the new TZDEFAULT makefile
1573 macro, which defaults to /etc/localtime.
1575 Diagnostics and commentary now distinguish UT from UTC more
1576 carefully; see theory.html for more information about UT vs UTC.
1578 zic has been ported to GCC 8's -Wstringop-truncation option.
1579 (Problem reported by Martin Sebor.)
1581 Changes to documentation and commentary
1583 The zic man page now documents the longstanding behavior that
1584 times and years can be out of the usual range, with negative times
1585 counting backwards from midnight and with year 0 preceding year 1.
1586 (Problem reported by Michael Deckers.)
1588 The theory.html file now mentions the POSIX limit of six chars
1589 per abbreviation, and lists alphabetic abbreviations used.
1591 The files tz-art.htm and tz-link.htm have been renamed to
1592 tz-art.html and tz-link.html, respectively, for consistency with
1593 other file names and to simplify web server configuration.
1596 Release 2017c - 2017-10-20 14:49:34 -0700
1599 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1600 Fiji ends DST 2018-01-14, not 2018-01-21.
1601 Namibia switches from +01/+02 to +02 on 2018-04-01.
1602 Sudan switches from +03 to +02 on 2017-11-01.
1603 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1604 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1605 A new file tzdata.zi now holds a small text copy of all data.
1606 The zic input format has been regularized slightly.
1608 Changes to future timestamps
1610 Northern Cyprus has decided to resume EU rules starting
1611 2017-10-29, thus reinstituting winter time.
1613 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1614 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1617 Namibia will switch from +01 with DST to +02 all year on
1618 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1619 at 02:00. (Thanks to Steffen Thorsen.)
1621 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1622 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1623 Africa/Juba is no longer a link to Africa/Khartoum.
1625 Tonga has likely ended its experiment with DST, and will not
1626 adjust its clocks on 2017-11-05. Although Tonga has not announced
1627 whether it will continue to observe DST, the IATA is assuming that
1628 it will not. (Thanks to David Wade.)
1630 Turks & Caicos will switch from -04 all year to -05 with US DST on
1631 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1632 at 02:00. (Thanks to Steffen Thorsen.)
1634 Changes to past timestamps
1636 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1637 (Thanks to Arthur David Olson.)
1639 Detroit did not observe DST in 1967.
1641 Use railway time for Asia/Kolkata before 1941, by switching to
1642 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1643 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1645 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1646 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1648 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1649 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1651 Adjust the 1867 transition in Alaska to better reflect the
1652 historical record, by changing it to occur on 1867-10-18 at 15:30
1653 Sitka time rather than at the start of 1867-10-17 local time.
1654 Although strictly speaking this is accurate only for Sitka,
1655 the rest of Alaska's blanks need to be filled in somehow.
1657 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1658 (Thanks to Michael Deckers.)
1660 Add 7 s to the UT offset in Asia/Yangon before 1920.
1662 Changes to zone names
1664 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1665 exceeded the 14-character limit and was an unused misnomer anyway.
1667 Changes to build procedure
1669 To support applications that prefer to read time zone data in text
1670 form, two zic input files tzdata.zi and leapseconds are now
1671 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1672 leapseconds tzdata.zi' can reproduce the tzdata binary files
1673 without and with leap seconds, respectively. To prevent these two
1674 new files from being installed, use 'make TZDATA_TEXT=', and to
1675 suppress leap seconds from the tzdata text installation, use 'make
1676 TZDATA_TEXT=tzdata.zi'.
1678 'make BACKWARD=' now suppresses backward-compatibility names
1679 like 'US/Pacific' that are defined in the 'backward' and
1682 'make check' now works on systems that lack a UTF-8 locale,
1683 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1684 the name of a UTF-8 locale, if you have one.
1686 Y2K runtime checks are no longer enabled by default. Add
1687 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1688 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1689 to disable them. (New name suggested by Brian Inglis.)
1691 The build procedure for zdump now works on AIX 7.1.
1692 (Problem reported by Kees Dekker.)
1696 zic and the reference runtime now reject multiple leap seconds
1697 within 28 days of each other, or leap seconds before the Epoch.
1698 As a result, support for double leap seconds, which was
1699 obsolescent and undocumented, has been removed. Double leap
1700 seconds were an error in the C89 standard; they have never existed
1701 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1702 noticing glitches in the code that uncovered this problem.)
1704 zic now warns about use of the obsolescent and undocumented -y
1705 option, and about use of the obsolescent TYPE field of Rule lines.
1707 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1708 weekdays; formerly it rejected them due to a bug. Conversely, zic
1709 no longer considers non-prefixes to be abbreviations; for example,
1710 it no longer accepts "lF" as an abbreviation for "lastFriday".
1711 Also, zic warns about the undocumented usage with a "last-"
1712 prefix, e.g., "last-Fri".
1714 Similarly, zic now accepts the unambiguous abbreviation "L" for
1715 "Link" in ordinary context and for "Leap" in leap-second context.
1716 Conversely, zic no longer accepts non-prefixes such as "La" as
1717 abbreviations for words like "Leap".
1719 zic no longer accepts leap second lines in ordinary input, or
1720 ordinary lines in leap second input. Formerly, zic sometimes
1721 warned about this undocumented usage and handled it incorrectly.
1723 The new macro HAVE_TZNAME governs whether the tzname external
1724 variable is exported, instead of USG_COMPAT. USG_COMPAT now
1725 governs only the external variables "timezone" and "daylight".
1726 This change is needed because the three variables are not in the
1727 same category: although POSIX requires tzname, it specifies the
1728 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
1729 if not defined, the code attempts to guess it from other macros.
1731 localtime.c and difftime.c no longer require stdio.h, and .c files
1732 other than zic.c no longer require sys/wait.h.
1734 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
1736 Calculation of time_t extrema works around a bug in GCC 4.8.4
1737 (Reported by Stan Shebs and Joseph Myers.)
1739 zic.c no longer mistranslates formats of line numbers in non-English
1740 locales. (Problem reported by Benno Schulenberg.)
1742 Several minor changes have been made to the code to make it a
1743 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
1744 Dekker for reporting the problems.)
1746 Changes to documentation and commentary
1748 The two new files 'theory.html' and 'calendars' contain the
1749 contents of the removed file 'Theory'. The goal is to document
1750 tzdb theory more accessibly.
1752 The zic man page now documents abbreviation rules.
1754 tz-link.htm now covers how to apply tzdata changes to clients.
1755 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
1757 The leap-seconds.list URL has been updated to something that is
1758 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
1760 Release 2017b - 2017-03-17 07:30:38 -0700
1762 Briefly: Haiti has resumed DST.
1764 Changes to past and future timestamps
1766 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
1768 Changes to past timestamps
1770 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1772 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1773 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
1777 The reference localtime implementation now falls back on the
1778 current US daylight-saving transition rules rather than the
1779 1987-2006 rules. This fallback occurs only when (1) the TZ
1780 environment variable has a value like "AST4ADT" that asks
1781 for daylight saving time but does not specify the rules, (2) there
1782 is no file by that name, and (3) the TZDEFRULES file cannot be
1783 loaded. (Thanks to Tom Lane.)
1786 Release 2017a - 2017-02-28 00:05:36 -0800
1788 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1791 Changes to future timestamps
1793 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
1795 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1796 Its clocks diverge from America/Santiago starting 2017-05-13 at
1797 23:00, hiving off a new zone America/Punta_Arenas. Although the
1798 Chilean government says this change expires in May 2019, for now
1799 assume it's permanent. (Thanks to Juan Correa and Deborah
1800 Goldsmith.) This also affects Antarctica/Palmer.
1802 Changes to past timestamps
1804 Fix many entries for historical timestamps for Europe/Madrid
1805 before 1979, to agree with tables compiled by Pere Planesas of the
1806 National Astronomical Observatory of Spain. As a side effect,
1807 this changes some timestamps for Africa/Ceuta before 1929, which
1808 are probably guesswork anyway. (Thanks to Steve Allen and
1809 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1810 correcting the 1901 transition.)
1812 Ecuador observed DST from 1992-11-28 to 1993-02-05.
1813 (Thanks to Alois Treindl.)
1815 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1816 (Thanks to Stepan Golosunov.)
1818 Changes to past and future time zone abbreviations
1820 Switch to numeric time zone abbreviations for South America, as
1821 part of the ongoing project of removing invented abbreviations.
1822 This avoids the need to invent an abbreviation for the new Chilean
1823 new zone. Similarly, switch from invented to numeric time zone
1824 abbreviations for Afghanistan, American Samoa, the Azores,
1825 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1826 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1827 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1828 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1829 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1830 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1831 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1832 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1833 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1834 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1835 for half-hour daylight saving time in Belize before 1944 and in
1836 the Dominican Republic before 1975; and for Canary Islands before
1837 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1838 Indian Summer Time before 1942, for Indonesia before around 1964,
1839 for Kenya before 1960, for Liberia before 1973, for Madeira before
1840 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1841 Pakistan before 1971, for Western Sahara before 1977, and for
1842 Zaporozhye in 1880-1924.
1844 For Alaska time from 1900 through 1967, instead of "CAT" use the
1845 abbreviation "AST", the abbreviation commonly used at the time
1846 (Atlantic Standard Time had not been standardized yet). Use "AWT"
1847 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1849 Use "CST" and "CDT" instead of invented abbreviations for Macau
1850 before 1999 and Taiwan before 1938, and use "JST" instead of the
1851 invented abbreviation "JCST" for Japan and Korea before 1938.
1853 Change to database entry category
1855 Move the Pacific/Johnston link from 'australasia' to 'backward',
1856 since Johnston is now uninhabited.
1860 zic no longer mishandles some transitions in January 2038 when it
1861 attempts to work around Qt bug 53071. This fixes a bug affecting
1862 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
1863 now contains a workaround, useful when loading a file generated by
1864 a buggy zic. (Problem and localtime.c fix reported by Bradley
1867 zdump -i now outputs non-hour numeric time zone abbreviations
1868 without a colon, e.g., "+0530" rather than "+05:30". This agrees
1869 with zic %z and with common practice, and simplifies auditing of
1872 zdump is now buildable again with -DUSE_LTZ=0.
1873 (Problem reported by Joseph Myers.)
1875 zdump.c now always includes private.h, to avoid code duplication
1876 with private.h. (Problem reported by Kees Dekker.)
1878 localtime.c no longer mishandles early or late timestamps
1879 when TZ is set to a POSIX-style string that specifies DST.
1880 (Problem reported by Kees Dekker.)
1882 date and strftime now cause %z to generate "-0000" instead of
1883 "+0000" when the UT offset is zero and the time zone abbreviation
1886 Changes to documentation and commentary
1888 The 'Theory' file now better documents choice of historical time
1889 zone abbreviations. (Problems reported by Michael Deckers.)
1891 tz-link.htm now covers leap smearing, which is popular in clouds.
1894 Release 2016j - 2016-11-22 23:17:13 -0800
1896 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1898 Changes to future timestamps
1900 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
1901 This hives off a new zone Europe/Saratov from Europe/Volgograd.
1902 (Thanks to Yuri Konotopov and Stepan Golosunov.)
1904 Changes to past timestamps
1906 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
1907 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1908 1999, not fall 1994. (Thanks to Stepan Golosunov.)
1910 Changes to past time zone abbreviations
1912 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
1913 summer time before 1948. The old use of "EET" was a typo.
1917 zic no longer mishandles file systems that lack hard links, fixing
1918 bugs introduced in 2016g. (Problems reported by Tom Lane.)
1919 Also, when the destination already contains symbolic links, zic
1920 should now work better on systems where the 'link' system call
1921 does not follow symbolic links.
1923 Changes to documentation and commentary
1925 tz-link.htm now documents the relationship between release version
1926 numbers and development-repository commit tags. (Suggested by
1929 The 'Theory' file now documents UT.
1931 iso3166.tab now accents "Curaçao", and commentary now mentions
1932 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
1935 Release 2016i - 2016-11-01 23:19:52 -0700
1937 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
1938 reintroduces DST on 2016-11-06.
1940 Changes to future timestamps
1942 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
1943 2017-01-15 at 03:00. Assume future observances in Tonga will be
1944 from the first Sunday in November through the third Sunday in
1945 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
1946 time zone abbreviations for this zone.
1948 Changes to past and future timestamps
1950 Northern Cyprus is now +03 year round, causing a split in Cyprus
1951 time zones starting 2016-10-30 at 04:00. This creates a zone
1952 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
1954 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
1955 (Thanks to Steffen Thorsen.)
1957 Changes to past timestamps
1959 Several corrections were made for pre-1975 timestamps in Italy.
1960 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
1963 First, the 1893-11-01 00:00 transition in Italy used the new UT
1964 offset (+01), not the old (+00:49:56). (Thanks to Michael
1967 Second, rules for daylight saving in Italy were changed to agree
1968 with Italy's National Institute of Metrological Research (INRiM)
1969 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
1970 Inglis, and Michael Deckers):
1972 The 1916-06-03 transition was at 24:00, not 00:00.
1974 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
1977 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
1980 The 1944-09-17 transition was at 03:00, not 01:00. This
1981 particular change is taken from Italian law as INRiM's table,
1982 (which says 02:00) appears to have a typo here. Also, keep the
1983 1944-04-03 transition for Europe/Rome, as Rome was controlled by
1986 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
1991 The code should now be buildable on AmigaOS merely by setting the
1992 appropriate Makefile variables. (From a patch by Carsten Larsen.)
1995 Release 2016h - 2016-10-19 23:17:57 -0700
1997 Changes to future timestamps
1999 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2000 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
2001 future fall transitions will be on the last Saturday of October
2002 at 01:00, which is consistent with predicted spring transitions
2003 on the last Saturday of March. (Thanks to Tim Parenti.)
2005 Changes to past timestamps
2007 In Turkey, transitions in 1986-1990 were at 01:00 standard time
2008 not at 02:00, and the spring 1994 transition was on March 20, not
2009 March 27. (Thanks to Kıvanç Yazan.)
2011 Changes to past and future time zone abbreviations
2013 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
2014 instead of alphabetic ones like "IST" and "LKT". Various
2015 English-language sources use "IST", "LKT" and "SLST", with no
2016 working consensus. (Usage of "SLST" mentioned by Sadika
2021 zic no longer mishandles relativizing file names when creating
2022 symbolic links like /etc/localtime, when these symbolic links
2023 are outside the usual directory hierarchy. This fixes a bug
2024 introduced in 2016g. (Problem reported by Andreas Stieger.)
2026 Changes to build procedure
2028 New rules 'traditional_tarballs' and 'traditional_signatures' for
2029 building just the traditional-format distribution. (Requested by
2032 The file 'version' is now put into the tzdata tarball too.
2033 (Requested by Howard Hinnant.)
2035 Changes to documentation and commentary
2037 The 'Theory' file now has a section on interface stability.
2038 (Requested by Paul Koning.) It also mentions features like
2039 tm_zone and localtime_rz that have long been supported by the
2042 tz-link.htm has improved coverage of time zone boundaries suitable
2043 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
2046 The US commentary now mentions Allen and the "day of two noons".
2048 The Fiji commentary mentions the government's 2016-10-03 press
2049 release. (Thanks to Raymond Kumar.)
2052 Release 2016g - 2016-09-13 08:56:38 -0700
2054 Changes to future timestamps
2056 Turkey switched from EET/EEST (+02/+03) to permanent +03,
2057 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
2058 than an invented abbreviation for the new time.
2060 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
2061 (Thanks to Tim Parenti.)
2063 Changes to past timestamps
2065 For America/Los_Angeles, spring-forward transition times have been
2066 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2069 For zones using Soviet time on 1919-07-01, transitions to UT-based
2070 time were at 00:00 UT, not at 02:00 local time. The affected
2071 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2072 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2074 Changes to past and future time zone abbreviations
2076 The Factory zone now uses the time zone abbreviation -00 instead
2077 of a long English-language string, as -00 is now the normal way to
2078 represent an undefined time zone.
2080 Several zones in Antarctica and the former Soviet Union, along
2081 with zones intended for ships at sea that cannot use POSIX TZ
2082 strings, now use numeric time zone abbreviations instead of
2083 invented or obsolete alphanumeric abbreviations. The affected
2084 zones are Antarctica/Casey, Antarctica/Davis,
2085 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2086 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2087 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2088 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2089 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2090 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2091 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2092 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2093 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2094 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2095 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2096 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2097 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2098 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2099 was replaced by +05, whereas MSK and MSD were kept as they are not
2100 our invention and are widely used.
2102 Changes to zone names
2104 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2105 (Thanks to David Massoud.)
2109 zic no longer generates binary files containing POSIX TZ-like
2110 strings that disagree with the local time type after the last
2111 explicit transition in the data. This fixes a bug with
2112 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2113 on the reference platform. (Thanks to Alexander Belopolsky for
2114 reporting the bug and suggesting a way forward.)
2116 If the installed localtime and/or posixrules files are symbolic
2117 links, zic now keeps them symbolic links when updating them, for
2118 compatibility with platforms like OpenSUSE where other programs
2119 configure these files as symlinks.
2121 zic now avoids hard linking to symbolic links, avoids some
2122 unnecessary mkdir and stat system calls, and uses shorter file
2125 zdump has a new -i option to generate transitions in a
2126 more-compact but still human-readable format. This option is
2127 experimental, and the output format may change in future versions.
2128 (Thanks to Jon Skeet for suggesting that an option was needed,
2129 and thanks to Tim Parenti and Chris Rovick for further comments.)
2131 Changes to build procedure
2133 An experimental distribution format is available, in addition
2134 to the traditional format which will continue to be distributed.
2135 The new format is a tarball tzdb-VERSION.tar.lz with signature
2136 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2137 tzdb-VERSION containing the code and data of the traditional
2138 two-tarball format, along with extra data that may be useful.
2139 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2140 for comments about the experimental format.)
2142 The release version number is now more accurate in the usual case
2143 where releases are built from a Git repository. For example, if
2144 23 commits and some working-file changes have been made since
2145 release 2016g, the version number is now something like
2146 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2147 Tagged releases use the same version number format as before,
2148 e.g., '2016g'. To support the more-accurate version number, its
2149 specification has moved from a line in the Makefile to a new
2150 source file 'version'.
2152 The experimental distribution contains a file to2050.tzs that
2153 contains what should be the output of 'zdump -i -c 2050' on
2154 primary zones. If this file is available, 'make check' now checks
2155 that zdump generates this output.
2157 'make check_web' now works on Fedora-like distributions.
2159 Changes to documentation and commentary
2161 tzfile.5 now documents the new restriction on POSIX TZ-like
2162 strings that is now implemented by zic.
2164 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2165 (Thanks to Alexander Belopolsky.)
2167 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2168 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2169 description of Java 8 has been brought up to date (thanks to
2170 Stephen Colebourne). Its description of local time on Mars has
2171 been updated to match current practice, and URLs have been updated
2172 and some obsolete ones removed.
2175 Release 2016f - 2016-07-05 16:26:51 +0200
2177 Changes affecting future timestamps
2179 The Egyptian government changed its mind on short notice, and
2180 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2181 (Thanks to Mina Samuel.)
2183 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2184 (Thanks to Stepan Golosunov.)
2186 Changes to past and future timestamps
2188 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2189 abbreviations instead of invented ones.
2191 Changes affecting past timestamps
2193 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2194 (Thanks to Stepan Golosunov.)
2197 Release 2016e - 2016-06-14 08:46:16 -0700
2199 Changes affecting future timestamps
2201 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2202 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2203 For future years, guess April's last Thursday to October's last
2204 Thursday except for Ramadan.
2206 Changes affecting past timestamps
2208 Locations while uninhabited now use '-00', not 'zzz', as a
2209 placeholder time zone abbreviation. This is inspired by Internet
2210 RFC 3339 and is more consistent with numeric time zone
2211 abbreviations already used elsewhere. The change affects several
2212 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2213 1920 and Antarctica/Troll before 2005.
2215 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2216 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2220 zic now outputs a dummy transition at time 2**31 - 1 in zones
2221 whose POSIX-style TZ strings contain a '<'. This mostly works
2222 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2223 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2225 Changes affecting documentation and commentary
2227 tz-link.htm says why governments should give plenty of notice for
2228 time zone or DST changes, and refers to Matt Johnson's blog post.
2230 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2233 Release 2016d - 2016-04-17 22:50:29 -0700
2235 Changes affecting future timestamps
2237 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2238 (Thanks to Alexander Krivenyshev for the heads-up.)
2240 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2241 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2243 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2244 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2245 at 02:00. (Thanks to Stepan Golosunov.)
2247 Changes affecting past timestamps
2249 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2250 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2251 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2252 the same change. (Thanks to Stepan Golosunov.)
2254 Russia and nearby locations had daylight-saving transitions on
2255 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2256 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2259 Many corrections to historical time in Kazakhstan from 1991
2260 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2261 invented time zone abbreviations with numeric abbreviations.
2263 Changes to commentary
2265 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2268 Release 2016c - 2016-03-23 00:51:27 -0700
2270 Changes affecting future timestamps
2272 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2274 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2275 Correa for the heads-up, and to Tim Parenti for corrections.)
2276 Guess that future transitions are August's and May's second
2277 Saturdays at 24:00 mainland time. Also, call the period from
2278 2014-09-07 through 2016-05-14 daylight saving time instead of
2279 standard time, as that seems more appropriate now.
2281 Changes affecting past timestamps
2283 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2284 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2285 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2286 (Thanks to Stepan Golosunov.)
2288 Changes to commentary
2290 Several updates and URLs for historical and proposed Russian changes.
2291 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2294 Release 2016b - 2016-03-12 17:30:14 -0800
2298 Starting with release 2016b, some data entries cause zic implementations
2299 derived from tz releases 2005j through 2015e to issue warnings like
2300 "time zone abbreviation differs from POSIX standard (+03)".
2301 These warnings should not otherwise affect zic's output and can safely be
2302 ignored on today's platforms, as the warnings refer to a restriction in
2303 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2304 warnings is to upgrade to zic derived from tz releases 2015f and later.
2306 Changes affecting future timestamps
2308 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2309 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2310 2016-03-27 at 02:00 local time. They need distinct zones since their
2311 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2312 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2313 and local time. The Astrakhan change is already official; the others have
2314 passed the first reading in the State Duma and are extremely likely.
2315 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2316 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2317 and Stepan Golosunov for followup.)
2319 As a trial of a new system that needs less information to be made up,
2320 the new zones use numeric time zone abbreviations like "+04"
2321 instead of invented abbreviations like "ASTT".
2323 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2326 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2327 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2328 Saturday at 01:00, not March's last Friday at 24:00.
2330 Changes affecting past timestamps
2332 Europe/Chisinau observed DST during 1990, and switched from +04 to
2333 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2334 (Thanks to Stepan Golosunov.)
2336 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2337 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2341 tzselect's diagnostics and checking, and checktab.awk's checking,
2342 have been improved. (Thanks to J William Piggott.)
2344 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2346 tzselect now tests Julian-date TZ settings more accurately.
2347 (Thanks to J William Piggott.)
2349 Changes to commentary
2351 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2353 tzselect again limits its menu comments so that menus fit on a
2354 24×80 alphanumeric display.
2356 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2358 In the Theory file, the description of possible time zone abbreviations in
2359 tzdata has been cleaned up, as the old description was unclear and
2360 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2363 Release 2016a - 2016-01-26 23:28:02 -0800
2365 Changes affecting future timestamps
2367 America/Cayman will not observe daylight saving this year after all.
2368 Revert our guess that it would. (Thanks to Matt Johnson.)
2370 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2371 (Thanks to Alexander Krivenyshev.)
2373 Asia/Tehran now has DST predictions for the year 2038 and later,
2374 to be March 21 00:00 to September 21 00:00. This is likely better
2375 than predicting no DST, albeit off by a day every now and then.
2377 Changes affecting past and future timestamps
2379 America/Metlakatla switched from PST all year to AKST/AKDT on
2380 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2382 America/Santa_Isabel has been removed, and replaced with a
2383 backward compatibility link to America/Tijuana. Its contents were
2384 apparently based on a misreading of Mexican legislation.
2386 Changes affecting past timestamps
2388 Asia/Karachi's two transition times in 2002 were off by a minute.
2389 (Thanks to Matt Johnson.)
2391 Changes affecting build procedure
2393 An installer can now combine leap seconds with use of the backzone file,
2394 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2395 The old 'make posix_packrat' rule is now marked as obsolescent.
2396 (Thanks to Ian Abbott for an initial implementation.)
2398 Changes affecting documentation and commentary
2400 A new file LICENSE makes it easier to see that the code and data
2401 are mostly public-domain. (Thanks to James Knight.) The three
2402 non-public-domain files now use the current (3-clause) BSD license
2403 instead of older versions of that license.
2405 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2406 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2407 on editing tz source files (with a mention of Sublime zoneinfo,
2408 thanks to Gilmore Davidson).
2410 The Theory and asia files now mention the 2015 book "The Global
2411 Transformation of Time, 1870-1950", and cite a couple of reviews.
2413 The America/Chicago entry now documents the informal use of US
2414 central time in Fort Pierre, South Dakota. (Thanks to Rick
2415 McDermid, Matt Johnson, and Steve Jones.)
2418 Release 2015g - 2015-10-01 00:39:51 -0700
2420 Changes affecting future timestamps
2422 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2425 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2426 (Thanks to Alexander Krivenyshev.)
2428 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2429 (Thanks to Ken Rylander.)
2431 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2432 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2433 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2435 Changes affecting past timestamps
2437 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2439 Changes affecting code
2441 localtime no longer mishandles America/Anchorage after 2037.
2442 (Thanks to Bradley White for reporting the bug.)
2444 On hosts with signed 32-bit time_t, localtime no longer mishandles
2445 Pacific/Fiji after 2038-01-16 14:00 UTC.
2447 The localtime module allows the variables 'timezone', 'daylight',
2448 and 'altzone' to be in common storage shared with other modules,
2449 and declares them in case the system <time.h> does not.
2450 (Problems reported by Kees Dekker.)
2452 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2453 This simplifies the code and is consistent with zdump.c.
2454 (Problem reported by Christos Zoulas.)
2456 Changes affecting documentation
2458 The tzfile man page now documents that transition times denote the
2459 starts (not the ends) of the corresponding time periods.
2460 (Ambiguity reported by Bill Seymour.)
2463 Release 2015f - 2015-08-10 18:06:56 -0700
2465 Changes affecting future timestamps
2467 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2468 The abbreviation remains "KST". (Thanks to Robert Elz.)
2470 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2473 Changes affecting past and future timestamps
2475 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2476 (Thanks to Roman Tudos.)
2478 Changes affecting data format and code
2480 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2481 field of a Rule line should now be '-'; the old values 'even',
2482 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2483 Although the implementation has not changed, these features do not
2484 work in the default installation, they are not used in the data,
2485 and they are now considered obsolescent.
2487 zic now checks that two rules don't take effect at the same time.
2488 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2489 simultaneity are now documented.
2491 The two characters '%z' in a zone format now stand for the UT
2492 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2493 five hours and thirty minutes ahead. This better supports time
2494 zone abbreviations conforming to POSIX.1-2001 and later.
2496 Changes affecting installed data files
2498 Comments for America/Halifax and America/Glace_Bay have been improved.
2499 (Thanks to Brian Inglis.)
2501 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2502 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2503 installed data files for Europe/Simferopol and Europe/Tallinn.
2504 It does not affect timestamps. (Thanks to Howard Hinnant.)
2506 Changes affecting code
2508 zdump and zic no longer warn about valid time zone abbreviations
2511 Some Visual Studio 2013 warnings have been suppressed.
2512 (Thanks to Kees Dekker.)
2514 'date' no longer sets the time of day and its -a, -d, -n and -t
2515 options have been removed. Long obsolescent, the implementation
2516 of these features had porting problems. Builders no longer need
2517 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2518 (Thanks to Kees Dekker for pointing out the problem.)
2520 Changes affecting documentation
2522 The Theory file mentions naming issues earlier, as these seem to be
2523 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2525 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2527 Mention that Herbert Samuel introduced the term "Summer Time".
2530 Release 2015e - 2015-06-13 10:56:02 -0700
2532 Changes affecting future timestamps
2534 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2535 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2537 Assume Cayman Islands will observe DST starting next year, using US rules.
2538 Although it isn't guaranteed, it is the most likely.
2540 Changes affecting data format
2542 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2543 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2545 Changes affecting code
2547 When displaying data, tzselect converts it to the current locale's
2548 encoding if the iconv command works. (Problem reported by random832.)
2550 tzselect no longer mishandles Dominica, fixing a bug introduced
2551 in Release 2014f. (Problem reported by Owen Leibman.)
2553 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2554 This fixes a bug introduced in Release 2014f.
2555 (Problem reported by Leonardo Chiquitto.)
2558 Release 2015d - 2015-04-24 08:09:46 -0700
2560 Changes affecting future timestamps
2562 Egypt will not observe DST in 2015 and will consider canceling it
2563 permanently. For now, assume no DST indefinitely.
2564 (Thanks to Ahmed Nazmy and Tim Parenti.)
2566 Changes affecting past timestamps
2568 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2569 1966-07-01. Also, Yukon's time zone history is documented better.
2570 (Thanks to Brian Inglis and Dennis Ferguson.)
2572 Change affecting past and future time zone abbreviations
2574 The abbreviations for Hawaii-Aleutian standard and daylight times
2575 have been changed from HAST/HADT to HST/HDT, as per US Government
2576 Printing Office style. This affects only America/Adak since 1983,
2577 as America/Honolulu was already using the new style.
2579 Changes affecting code
2581 zic has some minor performance improvements.
2584 Release 2015c - 2015-04-11 08:55:55 -0700
2586 Changes affecting future timestamps
2588 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2589 not 00:00 on April's last Friday. 2015's transition will therefore be on
2590 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2591 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2593 Changes affecting past timestamps
2595 The following changes affect some pre-1991 Chile-related timestamps
2596 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2598 The 1910 transition was January 10, not January 1.
2600 The 1918 transition was September 10, not September 1.
2602 The UT -04 time observed from 1932 to 1942 is now considered to
2603 be standard time, not year-round DST.
2605 Santiago observed DST (UT -03) from 1946-07-15 through
2606 1946-08-31, then reverted to standard time, then switched to -05
2609 Assume transitions before 1968 were at 00:00, since we have no data
2612 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2613 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2615 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2616 and omit all transitions on Pacific/Easter from 1942 through 1946
2617 since we have no data suggesting that they existed.
2619 One more zone has been turned into a link, as it differed
2620 from an existing zone only for older timestamps. As usual,
2621 this change affects UT offsets in pre-1970 timestamps only.
2622 The zone's old contents have been moved to the 'backzone' file.
2623 The affected zone is America/Montreal.
2625 Changes affecting commentary
2627 Mention the TZUpdater tool.
2629 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2632 Release 2015b - 2015-03-19 23:28:11 -0700
2634 Changes affecting future timestamps
2636 Mongolia will start observing DST again this year, from the last
2637 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2638 (Thanks to Ganbold Tsagaankhuu.)
2640 Palestine will start DST on March 28, not March 27. Also,
2641 correct the fall 2014 transition from September 26 to October 24.
2642 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2644 Changes affecting past timestamps
2646 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2647 regression. (Thanks to Stuart Bishop for reporting the problem.)
2649 Some more zones have been turned into links, when they differed
2650 from existing zones only for older timestamps. As usual,
2651 these changes affect UT offsets in pre-1970 timestamps only.
2652 Their old contents have been moved to the 'backzone' file.
2653 The affected zones are: America/Antigua, America/Cayman,
2654 Pacific/Midway, and Pacific/Saipan.
2656 Changes affecting time zone abbreviations
2658 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2661 Changes affecting code
2663 Fix integer overflow bug in reference 'mktime' implementation.
2664 (Problem reported by Jörg Richter.)
2666 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2667 to be used in the same executable as standard-library time_t functions.
2668 (Problems reported by Bradley White.)
2670 Changes affecting commentary
2672 Cite the recent Mexican decree changing Quintana Roo's time zone.
2673 (Thanks to Carlos Raúl Perasso.)
2675 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2677 Update info about Mars time.
2680 Release 2015a - 2015-01-29 22:35:20 -0800
2682 Changes affecting future timestamps
2684 The Mexican state of Quintana Roo, represented by America/Cancun,
2685 will shift from Central Time with DST to Eastern Time without DST
2686 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2688 Chile will not change clocks in April or thereafter; its new standard time
2689 will be its old daylight saving time. This affects America/Santiago,
2690 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2692 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2693 (Thanks to Tim Parenti.)
2695 Changes affecting past timestamps
2697 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2698 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2699 Shanks about time in Iceland between 1837 and 1908.
2701 Some more zones have been turned into links, when they differed
2702 from existing zones only for older timestamps. As usual,
2703 these changes affect UT offsets in pre-1970 timestamps only.
2704 Their old contents have been moved to the 'backzone' file.
2705 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2708 Changes affecting code
2710 tzalloc now scrubs time zone abbreviations compatibly with the way
2711 that tzset always has, by replacing invalid bytes with '_' and by
2712 shortening too-long abbreviations.
2714 tzselect ports to POSIX awk implementations, no longer mishandles
2715 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2716 settings to the user. (Thanks to Stefan Kuhn.)
2718 Changes affecting build procedure
2720 'make check' now checks for links to links in the data.
2721 One such link (for Africa/Asmera) has been fixed.
2722 (Thanks to Stephen Colebourne for pointing out the problem.)
2724 Changes affecting commentary
2726 The leapseconds file commentary now mentions the expiration date.
2727 (Problem reported by Martin Burnicki.)
2729 Update Mexican Library of Congress URL.
2732 Release 2014j - 2014-11-10 17:37:11 -0800
2734 Changes affecting current and future timestamps
2736 Turks & Caicos' switch from US eastern time to UT -04 year-round
2737 did not occur on 2014-11-02 at 02:00. It's currently scheduled
2738 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
2740 Changes affecting past timestamps
2742 Many pre-1989 timestamps have been corrected for Asia/Seoul and
2743 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2744 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
2745 longer guess that Pyongyang mimicked Seoul time after World War II,
2746 as this is politically implausible.
2748 Some more zones have been turned into links, when they differed
2749 from existing zones only for older timestamps. As usual,
2750 these changes affect UT offsets in pre-1970 timestamps only.
2751 Their old contents have been moved to the 'backzone' file.
2752 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2753 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2754 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2757 Changes affecting commentary
2759 The commentary is less enthusiastic about Shanks as a source,
2760 and is more careful to distinguish UT from UTC.
2763 Release 2014i - 2014-10-21 22:04:57 -0700
2765 Changes affecting future timestamps
2767 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2768 (Thanks to Ken Rylander for the heads-up.) Guess that future
2769 years will use a similar pattern.
2771 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2772 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2773 (Thanks to Kiley Walbom for the heads-up.)
2775 Changes affecting time zone abbreviations
2777 Since Belarus is not changing its clocks even though Moscow is,
2778 the time zone abbreviation in Europe/Minsk is changing from FET
2779 to its more-traditional value MSK on 2014-10-26 at 01:00.
2780 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2782 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2783 Indochina, to distinguish it better from ICT (+07).
2785 Changes affecting past timestamps
2787 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2788 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2789 authoritative book). Asia/Ho_Chi_Minh has been added to
2790 zone1970.tab, to give tzselect users in Vietnam two choices,
2791 since north and south Vietnam disagreed after our 1970 cutoff.
2793 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2794 they differed from existing zones only for older timestamps. As
2795 usual, these changes affect pre-1970 timestamps only. Their old
2796 contents have been moved to the 'backzone' file.
2798 Changes affecting code
2800 The time-related library functions now set errno on failure, and
2801 some crashes in the new tzalloc-related library functions have
2802 been fixed. (Thanks to Christos Zoulas for reporting most of
2803 these problems and for suggesting fixes.)
2805 If USG_COMPAT is defined and the requested timestamp is standard time,
2806 the tz library's localtime and mktime functions now set the extern
2807 variable timezone to a value appropriate for that timestamp; and
2808 similarly for ALTZONE, daylight saving time, and the altzone variable.
2809 This change is a companion to the tzname change in 2014h, and is
2810 designed to make timezone and altzone more compatible with tzname.
2812 The tz library's functions now set errno to EOVERFLOW if they fail
2813 because the result cannot be represented. ctime and ctime_r now
2814 return NULL and set errno when a timestamp is out of range, rather
2815 than having undefined behavior.
2817 Some bugs associated with the new 2014g functions have been fixed.
2818 This includes a bug that largely incapacitated the new functions
2819 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
2820 It also includes some uses of uninitialized variables after tzalloc.
2821 The new code uses the standard type 'ssize_t', which the Makefile
2822 now gives porting advice about.
2824 Changes affecting commentary
2826 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2829 Release 2014h - 2014-09-25 18:59:03 -0700
2831 Changes affecting past timestamps
2833 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2835 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2836 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
2838 Some more zones have been turned into links, when they differed
2839 from existing zones only for older timestamps. As usual,
2840 these changes affect UT offsets in pre-1970 timestamps only.
2841 Their old contents have been moved to the 'backzone' file.
2842 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2843 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2844 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2846 Changes affecting code
2848 zdump -V and -v now output gmtoff= values on all platforms,
2849 not merely on platforms defining TM_GMTOFF.
2851 The tz library's localtime and mktime functions now set tzname to a value
2852 appropriate for the requested timestamp, and zdump now uses this
2853 on platforms not defining TM_ZONE, fixing a 2014g regression.
2854 (Thanks to Tim Parenti for reporting the problem.)
2856 The tz library no longer sets tzname if localtime or mktime fails.
2858 zdump -c no longer mishandles transitions near year boundaries.
2859 (Thanks to Tim Parenti for reporting the problem.)
2861 An access to uninitialized data has been fixed.
2862 (Thanks to Jörg Richter for reporting the problem.)
2864 When THREAD_SAFE is defined, the code ports to the C11 memory model.
2865 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2866 and two threads race to initialize data used by gmtime-like functions.
2867 (Thanks to Andy Heninger for reporting the problems.)
2869 Changes affecting build procedure
2871 'make check' now checks better for properly-sorted data.
2873 Changes affecting documentation and commentary
2875 zdump's gmtoff=N output is now documented, and its isdst=D output
2876 is now documented to possibly output D values other than 0 or 1.
2878 zdump -c's treatment of years is now documented to use the
2879 Gregorian calendar and Universal Time without leap seconds,
2880 and its behavior at cutoff boundaries is now documented better.
2881 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2883 Programs are now documented to use the proleptic Gregorian calendar.
2884 (Thanks to Alan Barrett for the suggestion.)
2886 Fractional-second GMT offsets have been documented for civil time
2887 in 19th-century Chennai, Jakarta, and New York.
2890 Release 2014g - 2014-08-28 12:31:23 -0700
2892 Changes affecting future timestamps
2894 Turks & Caicos is switching from US eastern time to UT -04
2895 year-round, modeled as a switch on 2014-11-02 at 02:00.
2896 [As noted in 2014j, this switch was later delayed.]
2898 Changes affecting past timestamps
2900 Time in Russia or the USSR before 1926 or so has been corrected by
2901 a few seconds in the following zones: Asia/Irkutsk,
2902 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
2903 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
2904 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
2905 Vladimir Karpinsky.)
2907 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
2908 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
2909 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
2910 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
2911 (Thanks to Stephen Colebourne for pointing to the decree.)
2913 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
2915 A new file 'backzone' contains data which may appeal to
2916 connoisseurs of old timestamps, although it is out of scope for
2917 the tz database, is often poorly sourced, and contains some data
2918 that is known to be incorrect. The new file is not recommended
2919 for ordinary use and its entries are not installed by default.
2920 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
2921 Isle of Man entries.)
2923 Some more zones have been turned into links, when they differed
2924 from existing zones only for older timestamps. As usual,
2925 these changes affect UT offsets in pre-1970 timestamps only.
2926 Their old contents have been moved to the 'backzone' file.
2927 The affected zones are: Africa/Bangui, Africa/Brazzaville,
2928 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
2929 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
2931 Changes affecting code
2933 Unless NETBSD_INSPIRED is defined to 0, the tz library now
2934 supplies functions for creating and using objects that represent
2935 timezones. The new functions are tzalloc, tzfree, localtime_rz,
2936 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
2937 time2posix_z. They are intended for performance: for example,
2938 localtime_rz (unlike localtime_r) is trivially thread-safe without
2939 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
2940 functions, and to Alan Barrett and Jonathan Lennox for helping to
2943 zdump now builds with the tz library unless USE_LTZ is defined to 0,
2944 This lets zdump use tz features even if the system library lacks them.
2945 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
2946 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
2948 zdump now uses localtime_rz if available, as it's significantly faster,
2949 and it can help zdump better diagnose invalid timezone names.
2950 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
2951 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
2952 not available, zdump now uses localtime_r and tzset if available,
2953 as this is a bit cleaner and faster than plain localtime. Compile
2954 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
2955 lacks these two functions.
2957 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
2958 Although not needed for tz's own applications, which are single-threaded,
2959 this supports POSIX better if the tz library is used in multithreaded apps.
2961 Some crashes have been fixed when zdump or the tz library is given
2962 invalid or outlandish input.
2964 The tz library no longer mishandles leap seconds on platforms with
2965 unsigned time_t in timezones that lack ordinary transitions after 1970.
2967 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
2968 already defined, to make it easier to configure on common platforms.
2969 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
2971 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
2972 assumes that reading uninitialized memory yields garbage values
2973 but does not cause other problems such as traps.
2975 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
2976 more likely to guess right for ambiguous timestamps near
2977 transitions where tm_isdst does not change.
2979 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
2980 strftime_l for compatibility with recent versions of POSIX.
2981 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
2982 to 1 on recent POSIX versions, and to 0 otherwise.
2984 tzselect -c now uses a hybrid distance measure that works better
2985 in Africa. (Thanks to Alan Barrett for noting the problem.)
2987 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
2988 or when time_tz is defined.
2990 When HAVE_UTMPX_H is set the 'date' command now builds on systems
2991 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
2992 the date it updates the wtmpx file if _PATH_WTMPX is defined.
2993 This affects GNU/Linux and similar systems.
2995 For easier maintenance later, some C code has been simplified,
2996 some lint has been removed, and the code has been tweaked so that
2997 plain 'make' is more likely to work.
2999 The C type 'bool' is now used for boolean values, instead of 'int'.
3001 The long-obsolete LOCALE_HOME code has been removed.
3003 The long-obsolete 'gtime' function has been removed.
3005 Changes affecting build procedure
3007 'zdump' no longer links in ialloc.o, as it's not needed.
3009 'make check_time_t_alternatives' no longer assumes GNU diff.
3011 Changes affecting distribution tarballs
3013 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
3014 the tzdata tarball instead of the tzcode tarball, since they help
3015 maintain the data. The NEWS and Theory files are now also
3016 distributed in the tzdata tarball, as they're relevant for data.
3017 (Thanks to Alan Barrett for pointing this out.) Also, the
3018 leapseconds.awk file is no longer distributed in the tzcode
3019 tarball, since it belongs in the tzdata tarball (where 2014f
3020 inadvertently also distributed it).
3022 Changes affecting documentation and commentary
3024 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
3025 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
3028 The man pages have been updated to use function prototypes,
3029 to document thread-safe variants like localtime_r, and to document
3030 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
3033 The fields in Link lines have been renamed to be more descriptive
3034 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
3035 and LINK-TO has become LINK-NAME.
3037 tz-link.htm mentions the IETF's tzdist working group; Windows
3038 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
3040 Some broken URLs have been fixed in the commentary. (Thanks to
3043 Commentary about Philippines DST has been updated, and commentary
3044 on pre-1970 time in India has been added.
3047 Release 2014f - 2014-08-05 17:42:36 -0700
3049 Changes affecting future timestamps
3051 Russia will subtract an hour from most of its time zones on 2014-10-26
3052 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
3053 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
3054 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
3055 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
3056 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
3057 (Europe/Samara) are not changing their clocks. The changed zones are
3058 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
3059 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
3060 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
3061 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
3062 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
3063 but not its UTC offset. Two zones are added: Asia/Chita (split
3064 from Asia/Yakutsk, and also with two hours subtracted) and
3065 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
3066 subtracted). (Thanks to Tim Parenti for much of the above.)
3068 Changes affecting time zone abbreviations
3070 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3071 and similarly for the other Australian zones. That is, for eastern
3072 standard and daylight saving time the abbreviations are AEST and AEDT
3073 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3074 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3075 This change does not affect UT offsets, only time zone abbreviations.
3076 (Thanks to Rich Tibbett and many others.)
3078 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3079 effective 2014-10-26 at 02:00 local time.
3081 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3082 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3084 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3085 Similarly, prefer EET/EEST for eastern European time in Russia.
3087 Change time zone abbreviations in (western) Samoa to use "ST" and
3088 "DT" suffixes, as this is more likely to match common practice.
3089 Prefix "W" to (western) Samoa time when its standard-time offset
3090 disagrees with that of American Samoa.
3092 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3094 Time zone abbreviations have been updated for Japan's two time
3095 zones used 1896-1937. JWST now stands for Western Standard
3096 Time, and JCST for Central Standard Time (formerly this was CJT).
3097 These abbreviations are now used for time in Korea, Taiwan,
3098 and Sakhalin while controlled by Japan.
3100 Changes affecting past timestamps
3102 China's five zones have been simplified to two, since the post-1970
3103 differences in the other three seem to have been imaginary. The
3104 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3105 removed; backwards-compatibility links still work, albeit with
3106 different behaviors for timestamps before May 1980. Asia/Urumqi's
3107 1980 transition to UT +08 has been removed, so that it is now at
3108 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3109 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3111 Some zones have been turned into links, when they differed from existing
3112 zones only for older UT offsets where data entries were likely invented.
3113 These changes affect UT offsets in pre-1970 timestamps only. This is
3114 similar to the change in release 2013e, except this time for western
3115 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3116 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3117 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3118 Atlantic/St_Helena. This also affects the backwards-compatibility
3119 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3120 Tim Parenti, and David Patte for reporting problems in earlier
3121 versions of this change.)
3123 Asia/Shanghai's pre-standard-time UT offset has been changed from
3124 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3125 transition to standard time has been changed from 1928 to 1901.
3127 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3128 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3129 In 1946 it observed DST from 05-15 through 09-30; in 1947
3130 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3131 (Thanks to Yu-Cheng Chuang.)
3133 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3135 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3136 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3138 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3139 period from 1911 to 1950.
3141 Pacific/Chatham has been changed to New Zealand standard time plus
3142 45 minutes for the period before 1957, reflecting a 1956 remark in
3143 the New Zealand parliament.
3145 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3146 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3147 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3148 not 04-06 at 02:00; and there was no DST in 1920.
3150 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3152 Time in Russia before 1927 or so has been corrected by a few seconds in
3153 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3154 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3155 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3156 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3158 Changes affecting data format
3160 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3161 The new file's extended format allows multiple country codes per zone.
3162 The older file is still installed but is deprecated; its format is
3163 not changing and it will still be distributed for a while, but new
3164 applications should use the new file.
3166 The new file format simplifies maintenance of obscure locations.
3167 To test this, it adds coverage for the Crozet Islands and the
3168 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3170 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3171 It is still ASCII now, but commentary about the switch has been added.
3172 The new file 'zone1970.tab' already uses UTF-8.
3174 Changes affecting code
3176 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3177 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3179 'zic' no longer mishandles input when ignoring case in locales that
3180 are not compatible with English, e.g., unibyte Turkish locales when
3181 compiled with HAVE_GETTEXT.
3183 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3184 they no longer use ASCII '-' as if it were a dash.
3186 'zic' now rejects output file names that contain '.' or '..' components.
3187 (Thanks to Tim Parenti for reporting the problem.)
3189 'zic -v' now warns about output file names that do not follow
3190 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3191 David Olson for starting the ball rolling on this.)
3193 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3195 Changes affecting build procedure
3197 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3198 (Thanks to John Cochran.)
3200 Changes affecting documentation and commentary
3202 The 'Theory' file documents legacy names, the longstanding
3203 exceptions to the POSIX-inspired file name rules.
3205 The 'zic' documentation clarifies the role of time types when
3206 interpreting dates. (Thanks to Arthur David Olson.)
3208 Documentation and commentary now prefer UTF-8 to US-ASCII,
3209 allowing the use of proper accents in foreign words and names.
3210 Code and data have not changed because of this. (Thanks to
3211 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3214 Non-HTML documentation and commentary now use plain-text URLs instead of
3215 HTML insertions, and are more consistent about bracketing URLs when they
3216 are not already surrounded by white space. (Thanks to suggestions by
3219 There is new commentary about Xujiahui Observatory, the five time-zone
3220 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3221 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3222 warlord Jin Shuren in the data.
3224 Commentary about the coverage of each Russian zone has been standardized.
3225 (Thanks to Tim Parenti.)
3227 There is new commentary about contemporary timekeeping in Ethiopia.
3229 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3231 There is new commentary about time in Poland in 1919.
3233 Proper credit has been given to DST inventor George Vernon Hudson.
3235 Commentary about time in Metlakatla, AK and Resolute, NU has been
3236 improved, with a new source for the former.
3238 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3241 Commentary about permanent Antarctic bases has been updated.
3243 Several typos have been corrected. (Thanks to Tim Parenti for
3244 contributing some of these fixes.)
3246 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3247 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3248 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3249 (Thanks to a heads-up from Dirkjan Ochtman.)
3251 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3252 have been removed. These obsolescent US Naval Observatory entries were no
3253 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3256 Release 2014e - 2014-06-12 21:53:52 -0700
3258 Changes affecting near-future timestamps
3260 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3261 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3262 switch to standard time at 24:00 the last Thursday before Ramadan, and
3263 back to DST at 00:00 the first Friday after Ramadan.
3265 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3266 to Milamber Space Network.) Guess that from 2015 on Morocco will
3267 temporarily switch to standard time at 03:00 the last Saturday before
3268 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3270 Changes affecting past timestamps
3272 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3273 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3274 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3275 in 1991. (Thanks to Hank W. for reporting the problems.)
3277 Changes affecting commentary
3279 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3280 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3281 removes stale pointers to World Time Explorer and WORLDTIME.
3284 Release 2014d - 2014-05-27 21:34:40 -0700
3286 Changes affecting code
3288 zic no longer generates files containing timestamps before the Big Bang.
3289 This works around GNOME glib bug 878
3290 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3291 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3292 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3294 Changes affecting documentation
3296 tz-link.htm now mentions GNOME.
3299 Release 2014c - 2014-05-13 07:44:13 -0700
3301 Changes affecting near-future timestamps
3303 Egypt observes DST starting 2014-05-15 at 24:00.
3304 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3305 Details have not been announced, except that DST will not be observed
3306 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3307 Morocco, and that Egypt's future spring and fall transitions will be the
3308 same as 2010 when it last observed DST, namely April's last Friday at
3309 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3310 that Ramadan transitions will be at 00:00 standard time.
3312 Changes affecting code
3314 zic now generates transitions for minimum time values, eliminating guesswork
3315 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3317 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3319 Changes affecting commentary and documentation
3321 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3324 Release 2014b - 2014-03-24 21:28:50 -0700
3326 Changes affecting near-future timestamps
3328 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3329 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3331 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3332 Bengt-Inge Larsson.) This is currently an approximation; a better version
3333 will require the zic and localtime fixes mentioned below, and the plan is
3334 to wait for a while until at least the zic fixes propagate.
3336 Changes affecting code
3338 'zic' and 'localtime' no longer reject locations needing four transitions
3339 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3340 Also, 'zic' avoids some unlikely failures due to integer overflow.
3342 Changes affecting build procedure
3344 'make check' now detects Rule lines defined but never used.
3345 The NZAQ rules, an instance of this problem, have been removed.
3347 Changes affecting commentary and documentation
3349 Fix Tuesday/Thursday typo in description of time in Israel.
3350 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3352 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3353 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3354 library supports them.
3356 Add comments about Johnston Island time in the 1960s.
3357 (Thanks to Lyle McElhaney.)
3359 Morocco's 2014 DST start will be as predicted.
3360 (Thanks to Sebastien Willemijns.)
3363 Release 2014a - 2014-03-07 23:30:29 -0800
3365 Changes affecting near-future timestamps
3367 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3368 the heads-up, and to Tim Parenti for simplifying the update.)
3370 Changes affecting past timestamps
3372 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
3373 (Thanks to Steffen Thorsen.)
3375 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3376 (not 1992-01-01), and observed DST during the entire next winter.
3377 (Thanks to Vladimir in Moscow via Alois Treindl.)
3379 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3380 (Thanks to Avigdor Finkelstein.)
3382 Changes affecting code
3384 A uninitialized-storage bug in 'localtime' has been fixed.
3385 (Thanks to Logan Chien.)
3387 Changes affecting the build procedure
3389 The settings for 'make check_web' now default to Ubuntu 13.10.
3391 Changes affecting commentary and documentation
3393 The boundary of the US Pacific time zone is given more accurately.
3394 (Thanks to Alan Mintz.)
3396 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3398 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3400 Better descriptions of countries with same time zone history as
3401 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3403 Several changes affect tz-link.htm, the main web page.
3405 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3408 Mention xCal (Internet RFC 6321) and jCal.
3410 Microsoft has some support for tz database names.
3412 CLDR data formats include both XML and JSON.
3414 Mention Maggiolo's map of solar vs standard time.
3415 (Thanks to Arthur David Olson.)
3417 Mention TZ4Net. (Thanks to Matt Johnson.)
3419 Mention the timezone-olson Haskell package.
3421 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3423 Remove moribund links to daylight-savings-time.info and to
3424 Simple Timer + Clocks.
3426 Update two links. (Thanks to Oscar van Vlijmen.)
3428 Fix some formatting glitches, e.g., remove random newlines from
3429 abbr elements' title attributes.
3432 Release 2013i - 2013-12-17 07:25:23 -0800
3434 Changes affecting near-future timestamps:
3436 Jordan switches back to standard time at 00:00 on December 20, 2013.
3437 The 2006-2011 transition schedule is planned to resume in 2014.
3438 (Thanks to Steffen Thorsen.)
3440 Changes affecting past timestamps:
3442 In 2004, Cuba began DST on March 28, not April 4.
3443 (Thanks to Steffen Thorsen.)
3445 Changes affecting code
3447 The compile-time flag NOSOLAR has been removed, as nowadays the
3448 benefit of slightly shrinking runtime table size is outweighed by the
3449 cost of disallowing potential future updates that exceed old limits.
3451 Changes affecting documentation and commentary
3453 The files solar87, solar88, and solar89 are no longer distributed.
3454 They were a negative experiment - that is, a demonstration that
3455 tz data can represent solar time only with some difficulty and error.
3456 Their presence in the distribution caused confusion, as Riyadh
3457 civil time was generally not solar time in those years.
3459 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3462 Release 2013h - 2013-10-25 15:32:32 -0700
3464 Changes affecting current and future timestamps:
3466 Libya has switched its UT offset back to +02 without DST, instead
3467 of +01 with DST. (Thanks to Even Scharning.)
3469 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3470 (Thanks to Gwillim Law.)
3472 Changes affecting future timestamps:
3474 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3475 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3476 (Thanks to Steffen Thorsen.)
3478 Add entries for DST transitions in Morocco in the year 2038.
3479 This avoids some year-2038 glitches introduced in 2013g.
3480 (Thanks to Yoshito Umaoka for reporting the problem.)
3482 Changes affecting API
3484 The 'tzselect' command no longer requires the 'select' command,
3485 and should now work with /bin/sh on more platforms. It also works
3486 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3487 Patrick 'P. J.' McDermott and Alan Barrett.)
3489 Changes affecting code
3491 Fix localtime overflow bugs with 32-bit unsigned time_t.
3493 zdump no longer assumes sscanf returns maximal values on overflow.
3495 Changes affecting the build procedure
3497 The builder can specify which programs to use, if any, instead of
3498 'ar' and 'ranlib', and libtz.a is now built locally before being
3499 installed. (Thanks to Michael Forney.)
3501 A dependency typo in the 'zdump' rule has been fixed.
3502 (Thanks to Andrew Paprocki.)
3504 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3505 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3507 'make clean' no longer removes 'leapseconds', since it's
3508 host-independent and is part of the distribution.
3510 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3512 Changes affecting documentation and commentary
3514 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3515 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3517 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3518 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3519 longer maintained) and for old advisories. SOFA now does C.
3521 Release 2013g - 2013-09-30 21:08:26 -0700
3523 Changes affecting current and near-future timestamps
3525 Morocco now observes DST from the last Sunday in March to the last
3526 Sunday in October, not April to September respectively. (Thanks
3527 to Steffen Thorsen.)
3529 Changes affecting 'zic'
3531 'zic' now runs on platforms that lack both hard links and symlinks.
3532 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3533 Also, fix some bugs on platforms that lack hard links but have symlinks.
3535 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3536 to predict the far future, fixing a bug introduced in 2013e.
3538 Changes affecting the build procedure
3540 The 'leapseconds' file is again put into the tzdata tarball.
3541 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3542 Matt Burgess and Ian Abbott.) The timestamps of these and other
3543 dependent files in tarballs are adjusted more consistently.
3545 Changes affecting documentation and commentary
3547 The README file is now part of the data tarball as well as the code.
3548 It now states that files are public domain unless otherwise specified.
3549 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3550 Its details about the 1989 release moved to a place of honor near
3554 Release 2013f - 2013-09-24 23:37:36 -0700
3556 Changes affecting near-future timestamps
3558 Tocantins will very likely not observe DST starting this spring.
3559 (Thanks to Steffen Thorsen.)
3561 Jordan will likely stay at UT +03 indefinitely, and will not fall
3564 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3566 Changes affecting API
3568 The types of the global variables 'timezone' and 'altzone' (if present)
3569 have been changed back to 'long'. This is required for 'timezone'
3570 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3571 These variables were originally 'long' in the tz code, but were
3572 mistakenly changed to 'time_t' in 1987; nobody reported the
3573 incompatibility until now. The difference matters on x32, where
3574 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3576 Changes affecting the build procedure
3578 Avoid long strings in leapseconds.awk to work around a mawk bug.
3579 (Thanks to Cyril Baurand.)
3581 Changes affecting documentation and commentary
3583 New file 'NEWS' that contains release notes like this one.
3585 Paraguay's law does not specify DST transition time; 00:00 is customary.
3586 (Thanks to Waldemar Villamayor-Venialbo.)
3588 Minor capitalization fixes.
3590 Changes affecting version-control only
3592 The experimental GitHub repository now contains annotated and
3593 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3594 Releases are tagged starting with 2012e; earlier releases were
3595 done differently, and tags would either not have a simple name or
3596 not exactly match what was released.
3598 'make set-timestamps' is now simpler and a bit more portable.
3601 Release 2013e - 2013-09-19 23:50:04 -0700
3603 Changes affecting near-future timestamps
3605 This year Fiji will start DST on October 27, not October 20.
3606 (Thanks to David Wheeler for the heads-up.) For now, guess that
3607 Fiji will continue to spring forward the Sunday before the fourth
3610 Changes affecting current and future time zone abbreviations
3612 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3613 time zone abbreviations since 1932. (Thanks to George Ziegler,
3614 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3615 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3616 Asia/Makassar, and Asia/Pontianak.
3618 Use ART (UT -03, standard time), rather than WARST (also -03, but
3619 daylight saving time) for San Luis, Argentina since 2009.
3621 Changes affecting Godthåb timestamps after 2037 if version mismatch
3623 Allow POSIX-like TZ strings where the transition time's hour can
3624 range from -167 through 167, instead of the POSIX-required 0
3625 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3626 new Fiji rules. This is a more-compact way to represent
3627 far-future timestamps for America/Godthab, America/Santiago,
3628 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3629 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3630 this change. (Derived from a suggestion by Arthur David Olson.)
3632 Allow POSIX-like TZ strings where daylight saving time is in
3633 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3634 Argentina Summer Time all year. This supports a more-compact way
3635 to represent the 2013d data for America/Argentina/San_Luis.
3636 Because of the change for San Luis noted above this change does not
3637 affect the current data. (Thanks to Andrew Main (Zefram) for
3638 suggestions that improved this change.)
3640 Where these two TZ changes take effect, there is a minor extension
3641 to the tz file format in that it allows new values for the
3642 embedded TZ-format string, and the tz file format version number
3643 has therefore been increased from 2 to 3 as a precaution.
3644 Version-2-based client code should continue to work as before for
3645 all timestamps before 2038. Existing version-2-based client code
3646 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3647 files, and typically works in practice even for timestamps after
3648 2037; the only known exception is America/Godthab.
3650 Changes affecting timestamps before 1970
3652 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3653 some errors before 1947.
3655 Some zones have been turned into links, when they differ from existing
3656 zones only in older data entries that were likely invented or that
3657 differ only in LMT or transitions from LMT. These changes affect
3658 only timestamps before 1943. The affected zones are:
3659 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3660 America/Grenada, America/Guadeloupe, America/Marigot,
3661 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3662 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3663 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3664 confirming that the old Europe/Vaduz zone was wrong and the new
3665 link is better for WWII-era times.)
3667 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3668 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3671 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3672 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3675 Change the date of the circa-1850 Zurich transition from 1849-09-12
3676 to 1853-07-16, overriding Shanks with data from Messerli about
3677 postal and telegraph time in Switzerland.
3679 Changes affecting time zone abbreviations before 1970
3681 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3682 as Jakarta was called Batavia back then.
3684 Changes affecting API
3686 The 'zic' command now outputs a dummy transition when far-future
3687 data can't be summarized using a TZ string, and uses a 402-year
3688 window rather than a 400-year window. For the current data, this
3689 affects only the Asia/Tehran file. It does not affect any of the
3690 timestamps that this file represents, so zdump outputs the same
3691 information as before. (Thanks to Andrew Main (Zefram).)
3693 The 'date' command has a new '-r' option, which lets you specify
3694 the integer time to display, a la FreeBSD.
3696 The 'tzselect' command has two new options '-c' and '-n', which lets you
3697 select a zone based on latitude and longitude.
3699 The 'zic' command's '-v' option now warns about constructs that
3700 require the new version-3 binary file format. (Thanks to Arthur
3701 David Olson for the suggestion.)
3703 Support for floating-point time_t has been removed.
3704 It was always dicey, and POSIX no longer requires it.
3705 (Thanks to Eric Blake for suggesting to the POSIX committee to
3706 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3707 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3708 bugs and elucidating some of the corners of the old floating-point
3711 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3712 changed back to the old practice of using 'long' to represent UT
3713 offsets. This had been inadvertently and mistakenly changed to
3714 'int_fast32_t'. (Thanks to Christos Zoulas.)
3716 The code avoids undefined behavior on integer overflow in some
3717 more places, including gmtime, localtime, mktime and zdump.
3719 Changes affecting the zdump utility
3721 zdump now outputs "UT" when referring to Universal Time, not "UTC".
3722 "UTC" does not make sense for timestamps that predate the introduction
3723 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
3724 for clarifying UT vs UTC.)
3726 Data changes affecting behavior of tzselect and similar programs
3728 Country code BQ is now called the more-common name "Caribbean Netherlands"
3729 rather than the more-official "Bonaire, St Eustatius & Saba".
3731 Remove from zone.tab the names America/Montreal, America/Shiprock,
3732 and Antarctica/South_Pole, as they are equivalent to existing
3733 same-country-code zones for post-1970 timestamps. The data entries for
3734 these names are unchanged, so the names continue to work as before.
3736 Changes affecting code internals
3738 zic -c now runs way faster on 64-bit hosts when given large numbers.
3740 zic now uses vfprintf to avoid allocating and freeing some memory.
3742 tzselect now computes the list of continents from the data,
3743 rather than have it hard-coded.
3745 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3747 Changes affecting the build procedure
3749 The 'leapseconds' file is now generated automatically from a
3750 new file 'leap-seconds.list', which is a copy of
3751 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3752 A new source file 'leapseconds.awk' implements this.
3753 The goal is simplification of the future maintenance of 'leapseconds'.
3755 When building the 'posix' or 'right' subdirectories, if the
3756 subdirectory would be a copy of the default subdirectory, it is
3757 now made a symbolic link if that is supported. This saves about
3758 2 MB of file system space.
3760 The links America/Shiprock and Antarctica/South_Pole have been
3761 moved to the 'backward' file. This affects only nondefault builds
3762 that omit 'backward'.
3764 Changes affecting version-control only
3766 .gitignore now ignores 'date'.
3768 Changes affecting documentation and commentary
3770 Changes to the 'tzfile' man page
3772 It now mentions that the binary file format may be extended in
3773 future versions by appending data.
3775 It now refers to the 'zdump' and 'zic' man pages.
3777 Changes to the 'zic' man page
3779 It lists conditions that elicit a warning with '-v'.
3781 It says that the behavior is unspecified when duplicate names
3782 are given, or if the source of one link is the target of another.
3784 Its examples are updated to match the latest data.
3786 The definition of white space has been clarified slightly.
3787 (Thanks to Michael Deckers.)
3789 Changes to the 'Theory' file
3791 There is a new section about the accuracy of the tz database,
3792 describing the many ways that errors can creep in, and
3793 explaining why so many of the pre-1970 timestamps are wrong or
3794 misleading (thanks to Steve Allen, Lester Caine, and Garrett
3795 Wollman for discussions that contributed to this).
3797 The 'Theory' file describes LMT better (this follows a
3798 suggestion by Guy Harris).
3800 It refers to the 2013 edition of POSIX rather than the 2004 edition.
3802 It's mentioned that excluding 'backward' should not affect the
3803 other data, and it suggests at least one zone.tab name per
3804 inhabited country (thanks to Stephen Colebourne).
3806 Some longstanding restrictions on names are documented, e.g.,
3807 'America/New_York' precludes 'America/New_York/Bronx'.
3809 It gives more reasons for the 1970 cutoff.
3811 It now mentions which time_t variants are supported, such as
3812 signed integer time_t. (Thanks to Paul Goyette for reporting
3813 typos in an experimental version of this change.)
3815 (Thanks to Philip Newton for correcting typos in these changes.)
3817 Documentation and commentary is more careful to distinguish UT in
3818 general from UTC in particular. (Thanks to Steve Allen.)
3820 Add a better source for the Zurich 1894 transition.
3821 (Thanks to Pierre-Yves Berger.)
3823 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
3826 Release 2013d - 2013-07-05 07:38:01 -0700
3828 Changes affecting future timestamps:
3830 Morocco's midsummer transitions this year are July 7 and August 10,
3831 not July 9 and August 8. (Thanks to Andrew Paprocki.)
3833 Israel now falls back on the last Sunday of October.
3834 (Thanks to Ephraim Silverberg.)
3836 Changes affecting past timestamps:
3838 Specify Jerusalem's location more precisely; this changes the pre-1880
3841 Changing affecting metadata only:
3843 Fix typos in the entries for country codes BQ and SX.
3845 Changes affecting code:
3847 Rework the code to fix a bug with handling Australia/Macquarie on
3848 32-bit hosts (thanks to Arthur David Olson).
3850 Port to platforms like NetBSD, where time_t can be wider than long.
3852 Add support for testing time_t types other than the system's.
3853 Run 'make check_time_t_alternatives' to try this out.
3854 Currently, the tests fail for unsigned time_t;
3855 this should get fixed at some point.
3857 Changes affecting documentation and commentary:
3859 Deemphasize the significance of national borders.
3861 Update the zdump man page.
3863 Remove obsolete NOID comment (thanks to Denis Excoffier).
3865 Update several URLs and comments in the web pages.
3867 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3869 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3872 Release 2013c - 2013-04-19 16:17:40 -0700
3874 Changes affecting current and future timestamps:
3876 Palestine observed DST starting March 29, 2013. (Thanks to
3877 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
3878 with the predicted rules being the last Thursday in March at 24:00
3879 to the first Friday on or after September 21 at 01:00.
3881 Assume that the recent change to Paraguay's DST rules is permanent,
3882 by moving the end of DST to the 4th Sunday in March every year.
3883 (Thanks to Carlos Raúl Perasso.)
3885 Changes affecting past timestamps:
3887 Fix some historical data for Palestine to agree with that of
3888 timeanddate.com, as follows:
3890 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3893 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3896 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3898 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
3900 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
3902 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
3904 Fix times of habitation for Macquarie to agree with the Tasmania
3905 Parks & Wildlife Service history, which indicates that permanent
3906 habitation was 1899-1919 and 1948 on.
3908 Changing affecting metadata only:
3910 Macquarie Island is politically part of Australia, not Antarctica.
3911 (Thanks to Tobias Conradi.)
3913 Sort Macquarie more-consistently with other parts of Australia.
3914 (Thanks to Tim Parenti.)
3917 Release 2013b - 2013-03-10 22:33:40 -0700
3919 Changes affecting current and future timestamps:
3921 Haiti uses US daylight-saving rules this year, and presumably future years.
3922 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
3924 Paraguay will end DST on March 24 this year.
3925 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
3927 Morocco does not observe DST during Ramadan;
3928 try to predict Ramadan in Morocco as best we can.
3929 (Thanks to Erik Homoet for the heads-up.)
3931 Changes affecting commentary:
3933 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
3934 Update URL for Solaris. Mention Internet RFC 6557.
3935 Update Internet RFCs 2445->5545, 2822->5322.
3936 Switch from FTP to HTTP for Internet RFCs.
3939 Release 2013a - 2013-02-27 09:20:35 -0800
3941 Change affecting binary data format:
3943 The zone offset at the end of version-2-format zone files is now
3944 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
3946 Changes affecting current and future timestamps:
3948 Chile's 2013 rules, and we guess rules for 2014 and later, will be
3949 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
3950 (Thanks to Steffen Thorsen and Robert Elz.)
3952 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
3953 (Thanks to Tobias Conradi and Arthur David Olson.)
3955 Many changes affect historical timestamps before 1940.
3956 These were deduced from: Milne J. Civil time. Geogr J. 1899
3957 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
3959 Changes affecting the code:
3961 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
3962 the data). (Thanks to Arthur David Olson.)
3964 Fix localtime bug when time_t is unsigned and data files were generated
3965 by a signed time_t system. (Thanks to Doug Bailey for reporting and
3966 to Arthur David Olson for fixing.)
3968 Allow the email address for bug reports to be set by the packager.
3969 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
3971 Update HTML checking to be compatible with Ubuntu 12.10.
3973 Check that files are a safe subset of ASCII. At some point we may
3974 relax this requirement to a safe subset of UTF-8. Without the
3975 check, some non-UTF-8 encodings were leaking into the distribution.
3979 Restore a comment about copyright notices that was inadvertently deleted.
3980 (Thanks to Arthur David Olson.)
3982 Improve the commentary about which districts observe what times
3983 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
3985 Add web page links to tz.js.
3987 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
3990 Release 2012j - 2012-11-12 18:34:49 -0800
3992 Libya moved to CET this weekend, but with DST planned next year.
3993 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3995 Signatures now have the extension .asc, not .sign, as that's more
3996 standard. (Thanks to Phil Pennock.)
3998 The output of 'zdump --version', and of 'zic --version', now
3999 uses a format that is more typical for --version.
4000 (Thanks to Joseph S. Myers.)
4002 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
4003 now uses tz@iana.org rather than the old elsie address.
4005 zic -v now complains about abbreviations that are less than 3
4006 or more than 6 characters, as per Posix. Formerly, it checked
4007 for abbreviations that were more than 3.
4009 'make public' no longer puts its temporary directory under /tmp,
4010 and uses the just-built zic rather than the system zic.
4012 Various fixes to documentation and commentary.
4015 Release 2012i - 2012-11-03 12:57:09 -0700
4017 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
4019 Linker flags can now be specified via LDFLAGS.
4020 AWK now defaults to 'awk', not 'nawk'.
4021 The shell in tzselect now defaults to /bin/bash, but this can
4022 be overridden by specifying KSHELL.
4023 The main web page now mentions the unofficial GitHub repository.
4024 (Thanks to Mike Frysinger.)
4026 Tarball signatures can now be built by running 'make signatures'.
4027 There are also new makefile rules 'tarballs', 'check_public', and
4028 separate makefile rules for each tarball and signature file.
4029 A few makefile rules are now more portable to strict POSIX.
4031 The main web page now lists the canonical IANA URL.
4034 Release 2012h - 2012-10-26 22:49:10 -0700
4036 Bahia no longer has DST. (Thanks to Kelley Cook.)
4038 Tocantins has DST. (Thanks to Rodrigo Severo.)
4040 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
4042 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
4046 More C modernization, except that at Arthur David Olson's suggestion
4047 the instances of 'register' were kept.
4050 Release 2012g - 2012-10-17 20:59:45 -0700
4052 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
4054 Palestine fall 2012. (Thanks to Steffen Thorsen.)
4058 To attack the version-number problem, this release ships the file
4059 'Makefile' (which contains the release number) in both the tzcode and
4060 the tzdata tarballs. The two Makefiles are identical, and should be
4061 identical in any matching pair of tarballs, so it shouldn't matter
4062 which order you extract the tarballs. Perhaps we can come up with a
4063 better version-number scheme at some point; this scheme does have the
4064 virtue of not adding more files.
4067 Release 2012f - 2012-09-12 23:17:03 -0700
4069 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4070 20 this year. (Thanks to Steffen Thorsen.)
4073 Release 2012e - 2012-08-02 20:44:55 -0700
4075 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4076 (Thanks to Steffen Thorsen.)
4078 * Use a single version number for both code and data.
4080 * .gitignore: New file.
4082 * Remove trailing white space.
4085 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4087 Changes for Morocco's timestamps, which take effect in a couple of
4088 hours, along with infrastructure changes to accommodate how the tz
4089 code and data are released on IANA.
4092 Release data2012c - 2012-03-27 12:17:25 -0400
4095 Summer time changes for Morocco (to start late April 2012)
4098 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4101 Haiti following US/Canada rules for 2012 (and we're assuming,
4102 for now anyway, for the future).
4105 Release 2012b - 2012-03-02 12:29:15 +0700
4107 There is just one change to tzcode2012b (compared with 2012a):
4108 the Makefile that was accidentally included with 2012a has been
4109 replaced with the version that should have been there, which is
4110 identical with the previous version (from tzcode2011i).
4112 There are just two changes in tzdata2012b compared with 2012a.
4114 Most significantly, summer time in Cuba has been delayed 3 weeks
4115 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4116 date, as listed in 2012a) is just a little over a week away, this
4119 Less importantly, an excess tab in one of the changes in zone.tab
4120 in 2012a has been removed.
4123 Release 2012a - 2012-03-01 18:28:10 +0700
4125 The changes in tzcode2012a (compared to the previous version, 2011i)
4126 are entirely to the README and tz-art.htm and tz-link.htm files, if
4127 none of those concern you, you can ignore the code update. The changes
4128 reflect the changed addresses for the mailing list and the code and
4129 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4130 has been added to tz-link.htm).
4132 In tzdata2012a (compared to the previous release, which was 2011n)
4133 the major changes are:
4134 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4135 Falkland Islands onto permanent summer time (we're assuming for the
4136 foreseeable future, though 2012 is all we're fairly certain of.)
4137 Armenia has abolished Summer Time.
4138 Tokelau jumped the International Date Line back last December
4139 (just the same as their near neighbour, Samoa).
4140 America/Creston is a new zone for a small area of British Columbia
4141 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4143 Other minor changes are:
4144 Corrections to 1918 Canadian summer time end dates.
4145 Updated URL for UK time zone history (in comments)
4146 A few typos in Le Corre's list of free French place names (comments)
4149 Release data2011n - 2011-10-30 14:57:54 +0700
4151 There are three changes of note - most urgently, Cuba (America/Havana)
4152 has extended summer time by two weeks, now to end on Nov 13, rather than
4153 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4154 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4155 all, and consequently that zone has been removed (again) and reinstated
4156 in the "backward" file as a link to Europe/Chisinau. And third, the
4157 end date for Fiji's summer time this summer was moved forward from the
4158 earlier planned Feb 26, to Jan 22.
4160 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4161 (and the incorrect syntax that was in the 2011m version of that file
4162 is so fixed - it would have been fixed in a different way had this
4163 change not happened - that's the "missing" sccs version id).
4166 Release data2011m - 2011-10-24 21:42:16 +0700
4168 In particular, the typos in comments in the data (2011-11-17 should have
4169 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4170 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4171 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
4172 Tim Parenti, and also Denys Gavrysh)
4174 In addition, I added Europe/Tiraspol to zone.tab.
4176 This time, all the files have new version numbers... (including the files
4177 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4178 version numbers there...)
4181 Release data2011l - 2011-10-10 11:15:43 +0700
4183 There are just 2 changes that cause different generated tzdata files from
4184 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4185 is included, but commented out. Compared with the diff I sent out last week,
4186 this version also includes attributions for the sources for the changes
4187 (in much the same format as ado used, but the html tags have not been
4188 checked, verified, or used in any way at all, so if there are errors there,
4189 please let me know.)
4192 Release data2011k - 2011-09-20 17:54:03 -0400
4197 Release data2011j - 2011-09-12 09:22:49 -0400
4199 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4200 Tanzania); there are also two spelling corrections to comments in
4201 the australasia file (with thanks to Christos Zoulas).
4204 Release 2011i - 2011-08-29 05:56:32 -0400
4209 Release data2011h - 2011-06-15 18:41:48 -0400
4211 Russia and Curaçao changes
4214 Release 2011g - 2011-04-25 09:07:22 -0400
4216 update the rules for Egypt to reflect its abandonment of DST this year
4219 Release 2011f - 2011-04-06 17:14:53 -0400
4224 Release 2011e - 2011-03-31 16:04:38 -0400
4226 Morocco, Chile, and tz-link changes
4229 Release 2011d - 2011-03-14 09:18:01 -0400
4231 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4234 Release 2011c - 2011-03-07 09:30:09 -0500
4236 These do affect current timestamps in Chile and Annette Island, Canada.
4239 Release 2011b - 2011-02-07 08:44:50 -0500
4244 Release 2011a - 2011-01-24 10:30:16 -0500
4249 Release data2010o - 2010-11-01 09:18:23 -0400
4251 change to the end of DST in Fiji in 2011
4254 Release 2010n - 2010-10-25 08:19:17 -0400
4259 Release 2010m - 2010-09-27 09:24:48 -0400
4261 Hong Kong, Vostok, and zic.c changes
4264 Release 2010l - 2010-08-16 06:57:25 -0400
4269 Release 2010k - 2010-07-26 10:42:27 -0400
4274 Release 2010j - 2010-05-10 09:07:48 -0400
4276 changes for Bahía de Banderas and for version naming
4279 Release data2010i - 2010-04-16 18:50:45 -0400
4281 the end of DST in Morocco on 2010-08-08
4284 Release data2010h - 2010-04-05 09:58:56 -0400
4289 Release data2010g - 2010-03-24 11:14:53 -0400
4294 Release 2010f - 2010-03-22 09:45:46 -0400
4299 Release data2010e - 2010-03-08 14:24:27 -0500
4301 corrects the Dhaka bug found by Danvin Ruangchan
4304 Release data2010d - 2010-03-06 07:26:01 -0500
4309 Release 2010c - 2010-03-01 09:20:58 -0500
4311 changes including KRE's suggestion for earlier initialization of
4312 "goahead" and "goback" structure elements
4315 Release code2010a - 2010-02-16 10:40:04 -0500
4320 Release data2010b - 2010-01-20 12:37:01 -0500
4325 Release data2010a - 2010-01-18 08:30:04 -0500
4330 Release data2009u - 2009-12-26 08:32:28 -0500
4332 changes to DST in Bangladesh
4335 Release 2009t - 2009-12-21 13:24:27 -0500
4340 Release data2009s - 2009-11-14 10:26:32 -0500
4342 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4345 Release 2009r - 2009-11-09 10:10:31 -0500
4347 "antarctica" and "tz-link.htm" changes
4350 Release 2009q - 2009-11-02 09:12:40 -0500
4352 with two corrections as reported by Eric Muller and Philip Newton
4355 Release data2009p - 2009-10-23 15:05:27 -0400
4357 Argentina (including San Luis) changes (with the correction from
4361 Release data2009o - 2009-10-14 16:49:38 -0400
4363 Samoa (commentary only), Pakistan, and Bangladesh changes
4366 Release data2009n - 2009-09-22 15:13:38 -0400
4368 added commentary for Argentina and a change to the end of DST in
4372 Release data2009m - 2009-09-03 10:23:43 -0400
4374 Samoa and Palestine changes
4377 Release data2009l - 2009-08-14 09:13:07 -0400
4379 Samoa (comments only) and Egypt
4382 Release 2009k - 2009-07-20 09:46:08 -0400
4387 Release data2009j - 2009-06-15 06:43:59 -0400
4389 Bangladesh change (with a short turnaround since the DST change is
4393 Release 2009i - 2009-06-08 09:21:22 -0400
4395 updating for DST in Bangladesh this year
4398 Release 2009h - 2009-05-26 09:19:14 -0400
4403 Release data2009g - 2009-04-20 16:34:07 -0400
4408 Release data2009f - 2009-04-10 11:00:52 -0400
4410 correct DST in Pakistan
4413 Release 2009e - 2009-04-06 09:08:11 -0400
4418 Release 2009d - 2009-03-23 09:38:12 -0400
4420 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4423 Release data2009c - 2009-03-16 09:47:51 -0400
4425 change to the start of Cuban DST
4428 Release 2009b - 2009-02-09 11:15:22 -0500
4433 Release 2009a - 2009-01-21 10:09:39 -0500
4438 Release data2008i - 2008-10-21 12:10:25 -0400
4440 southamerica and zone.tab files, with Argentina DST rule changes and
4441 United States zone reordering and recommenting
4444 Release 2008h - 2008-10-13 07:33:56 -0400
4449 Release 2008g - 2008-10-06 09:03:18 -0400
4451 Fix a broken HTML anchor and update Brazil's DST transitions;
4452 there's also a slight reordering of information in tz-art.htm.
4455 Release data2008f - 2008-09-09 22:33:26 -0400
4460 Release 2008e - 2008-07-28 14:11:17 -0400
4462 changes by Arthur David Olson and Jesper Nørgaard Welen
4465 Release data2008d - 2008-07-07 09:51:38 -0400
4467 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4470 Release data2008c - 2008-05-19 17:48:03 -0400
4472 Pakistan, Morocco, and Mongolia
4475 Release data2008b - 2008-03-24 08:30:59 -0400
4477 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4481 Release 2008a - 2008-03-08 05:42:16 -0500
4486 Release 2007k - 2007-12-31 10:25:22 -0500
4488 most importantly, changes to the "southamerica" file based on
4489 Argentina's readoption of daylight saving time
4492 Release 2007j - 2007-12-03 09:51:01 -0500
4494 1. eliminate the "P" (parameter) macro;
4496 2. the "noncontroversial" changes circulated on the time zone
4497 mailing list (less the changes to "logwtmp.c");
4499 3. eliminate "too many transition" errors when "min" is used in time
4502 4. changes by Paul Eggert (including updated information for Venezuela).
4505 Release data2007i - 2007-10-30 10:28:11 -0400
4507 changes for Cuba and Syria
4510 Release 2007h - 2007-10-01 10:05:51 -0400
4512 changes by Paul Eggert, as well as an updated link to the ICU
4513 project in tz-link.htm
4516 Release 2007g - 2007-08-20 10:47:59 -0400
4518 changes by Paul Eggert
4520 The "leapseconds" file has been updated to incorporate the most
4521 recent International Earth Rotation and Reference Systems Service
4524 There's an addition to tz-art.htm regarding the television show "Medium".
4527 Release 2007f - 2007-05-07 10:46:46 -0400
4529 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4532 changes to zic.c to allow hour values greater than 24 (along with
4533 Paul's improved time value overflow checking)
4536 Release 2007e - 2007-04-02 10:11:52 -0400
4538 Syria and Honduras changes by Paul Eggert
4540 zic.c variable renaming changes by Arthur David Olson
4543 Release 2007d - 2007-03-20 08:48:30 -0400
4545 changes by Paul Eggert
4547 the elimination of white space at the ends of lines
4550 Release 2007c - 2007-02-26 09:09:37 -0500
4552 changes by Paul Eggert
4555 Release 2007b - 2007-02-12 09:34:20 -0500
4557 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4559 changes to the commentary in "leapseconds" reflecting the IERS
4560 announcement that there is to be no positive leap second at the end
4564 Release 2007a - 2007-01-08 12:28:29 -0500
4566 changes by Paul Eggert
4568 Derick Rethans's Asmara change
4570 Oscar van Vlijmen's Easter Island local mean time change
4572 symbolic link changes
4575 Release 2006p - 2006-11-27 08:54:27 -0500
4577 changes by Paul Eggert
4580 Release 2006o - 2006-11-06 09:18:07 -0500
4582 changes by Paul Eggert
4585 Release 2006n - 2006-10-10 11:32:06 -0400
4587 changes by Paul Eggert
4590 Release 2006m - 2006-10-02 15:32:35 -0400
4592 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4594 (minimalist) changes to zic.8 to clarify "until" information
4597 Release data2006l - 2006-09-18 12:58:11 -0400
4599 Paul's best-effort work on this coming weekend's Egypt time change
4602 Release 2006k - 2006-08-28 12:19:09 -0400
4604 changes by Paul Eggert
4607 Release 2006j - 2006-08-21 09:56:32 -0400
4609 changes by Paul Eggert
4612 Release code2006i - 2006-08-07 12:30:55 -0400
4616 Ken Pizzini's conversion script
4619 Release code2006h - 2006-07-24 09:19:37 -0400
4621 adds public domain notices to four files
4623 includes a fix for transition times being off by a second
4625 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4628 Release 2006g - 2006-05-08 17:18:09 -0400
4630 northamerica changes by Paul Eggert
4633 Release 2006f - 2006-05-01 11:46:00 -0400
4635 a missing version number problem is fixed (with thanks to Bradley
4636 White for catching the problem)
4639 Release 2006d - 2006-04-17 14:33:43 -0400
4641 changes by Paul Eggert
4643 added new items to tz-arts.htm that were found by Paul
4646 Release 2006c - 2006-04-03 10:09:32 -0400
4648 two sets of data changes by Paul Eggert
4650 a fencepost error fix in zic.c
4652 changes to zic.c and the "europe" file to minimize differences
4653 between output produced by the old 32-bit zic and the new 64-bit
4657 Release 2006b - 2006-02-20 10:08:18 -0500
4658 [tz32code2006b + tz64code2006b + tzdata2006b]
4662 All SCCS IDs were bumped to "8.1" for this release.
4665 Release 2006a - 2006-01-30 08:59:31 -0500
4667 changes by Paul Eggert (in particular, Indiana time zone moves)
4669 an addition to the zic manual page to describe how special-case
4670 transitions are handled
4673 Release 2005r - 2005-12-27 09:27:13 -0500
4675 Canadian changes by Paul Eggert
4677 They also add "<pre>" directives to time zone data files and reflect
4678 changes to warning message logic in "zdump.c" (but with calls to
4679 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4682 Release 2005q - 2005-12-13 09:17:09 -0500
4684 Nothing earth-shaking here:
4685 1. Electronic mail addresses have been removed.
4686 2. Casts of the return value of exit have been removed.
4687 3. Casts of the argument of is.* macros have been added.
4688 4. Indentation in one section of zic.c has been fixed.
4689 5. References to dead URLs in the data files have been dealt with.
4692 Release 2005p - 2005-12-05 10:30:53 -0500
4694 "systemv", "tz-link.htm", and "zdump.c" changes
4695 (less the casts of arguments to the is* macros)
4698 Release 2005o - 2005-11-28 10:55:26 -0500
4700 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4702 zdump.c lint fixes by Arthur David Olson
4705 Release 2005n - 2005-10-03 09:44:09 -0400
4707 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4711 Release 2005m - 2005-08-29 12:15:40 -0400
4713 changes by Paul Eggert (with a small tweak to the tz-art change)
4715 a declaration of an unused variable has been removed from zdump.c
4718 Release 2005l - 2005-08-22 12:06:39 -0400
4720 changes by Paul Eggert
4722 overflow/underflow checks by Arthur David Olson, minus changes to
4723 the "Theory" file about the pending addition of 64-bit data (I grow
4724 less confident of the changes being accepted with each passing day,
4725 and the changes no longer increase the data files nine-fold--there's
4726 less than a doubling in size by my local Sun's reckoning)
4729 Release 2005k - 2005-07-14 14:14:24 -0400
4731 The "leapseconds" file has been edited to reflect the recently
4732 announced leap second at the end of 2005.
4734 I've also deleted electronic mail addresses from the files as an
4738 Release 2005j - 2005-06-13 14:34:13 -0400
4740 These reflect changes to limit the length of time zone abbreviations
4741 and the characters used in those abbreviations.
4743 There are also changes to handle POSIX-style "quoted" timezone
4744 environment variables.
4746 The changes were circulated on the time zone mailing list; the only
4747 change since then was the removal of a couple of minimum-length of
4748 abbreviation checks.
4751 Release data2005i - 2005-04-21 15:04:16 -0400
4753 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4756 Release 2005h - 2005-04-04 11:24:47 -0400
4758 changes by Paul Eggert
4760 minor changes to Makefile and zdump.c to produce more useful output
4761 when doing a "make typecheck"
4764 Release 2005g - 2005-03-14 10:11:21 -0500
4766 changes by Paul Eggert (a change to current DST rules in Uruguay and
4767 an update to a link to time zone software)
4770 Release 2005f - 2005-03-01 08:45:32 -0500
4772 data and documentation changes by Paul Eggert
4775 Release 2005e - 2005-02-10 15:59:44 -0500
4780 Release code2005d - 2005-01-31 09:21:47 -0500
4782 make zic complain about links to links if the -v flag is used
4784 have "make public" do more code checking
4786 add an include to "localtime.c" for the benefit of gcc systems
4789 Release 2005c - 2005-01-17 18:36:29 -0500
4791 get better results when mktime runs on a system where time_t is double
4793 changes to the data files (most importantly to Paraguay)
4796 Release 2005b - 2005-01-10 09:19:54 -0500
4798 Get localtime and gmtime working on systems with exotic time_t types.
4800 Update the leap second commentary in the "leapseconds" file.
4803 Release 2005a - 2005-01-01 13:13:44 -0500
4808 Release code2004i - 2004-12-14 13:42:58 -0500
4810 Deal with systems where time_t is unsigned.
4813 Release code2004h - 2004-12-07 11:40:18 -0500
4815 64-bit-time_t changes
4818 Release 2004g - 2004-11-02 09:06:01 -0500
4820 update to Cuba (taking effect this weekend)
4822 other changes by Paul Eggert
4824 correction of the spelling of Oslo
4826 changed versions of difftime.c and private.h
4829 Release code2004f - 2004-10-21 10:25:22 -0400
4831 Cope with wide-ranging tm_year values.
4834 Release 2004e - 2004-10-11 14:47:21 -0400
4836 Brazil/Argentina/Israel changes by Paul Eggert
4838 changes to tz-link.htm by Paul
4840 one small fix to Makefile
4843 Release 2004d - 2004-09-22 08:27:29 -0400
4845 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4848 Release 2004c - 2004-08-11 12:06:26 -0400
4850 asctime-related changes
4852 (variants of) some of the documentation changes suggested by Paul Eggert
4855 Release 2004b - 2004-07-19 14:33:35 -0400
4857 data changes by Paul Eggert - most importantly, updates for Argentina
4860 Release 2004a - 2004-05-27 12:00:47 -0400
4862 changes by Paul Eggert
4864 Handle DST transitions that occur at the end of a month in some
4865 years but at the start of the following month in other years.
4867 Add a copy of the correspondence that's the basis for claims about
4868 DST in the Navajo Nation.
4871 Release 2003e - 2003-12-15 09:36:47 -0500
4873 changes by Arthur David Olson (primarily code changes)
4875 changes by Paul Eggert (primarily data changes)
4877 minor changes to "Makefile" and "northamerica" (in the latter case,
4878 optimization of the "Toronto" rules)
4881 Release 2003d - 2003-10-06 09:34:44 -0400
4883 changes by Paul Eggert
4886 Release 2003c - 2003-09-16 10:47:05 -0400
4888 Fix bad returns in zic.c's inleap function.
4889 Thanks to Bradley White for catching the problem!
4892 Release 2003b - 2003-09-16 07:13:44 -0400
4894 Add a "--version" option (and documentation) to the zic and zdump commands.
4896 changes to overflow/underflow checking in zic
4898 a localtime typo fix.
4900 Update the leapseconds and tz-art.htm files.
4903 Release 2003a - 2003-03-24 09:30:54 -0500
4905 changes by Paul Eggert
4907 a few additions and modifications to the tz-art.htm file
4910 Release 2002d - 2002-10-15 13:12:42 -0400
4912 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
4914 There's also a new time zone quote in "tz-art.htm".
4917 Release 2002c - 2002-04-04 11:55:20 -0500
4919 changes by Paul Eggert
4921 Change zic.c to avoid creating symlinks to files that don't exist.
4924 Release 2002b - 2002-01-28 12:56:03 -0500
4926 [These change notes are for Release 2002a, which was corrupted.
4927 2002b was a corrected version of 2002a.]
4929 changes by Paul Eggert
4931 Update the "leapseconds" file to note that there'll be no leap
4932 second at the end of June, 2002.
4934 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
4936 Change to "difftime.c" to avoid sizeof problems.
4939 Release 2001d - 2001-10-09 13:31:32 -0400
4941 changes by Paul Eggert
4944 Release 2001c - 2001-06-05 13:59:55 -0400
4946 changes by Paul Eggert and Andrew Brown
4949 Release 2001b - 2001-04-05 16:44:38 -0400
4951 changes by Paul Eggert (modulo jnorgard's typo fix)
4953 tz-art.htm has been HTMLified.
4956 Release 2001a - 2001-03-13 12:57:44 -0500
4958 changes by Paul Eggert
4960 An addition to the "leapseconds" file: comments with the text of the
4961 latest IERS leap second notice.
4963 Trailing white space has been removed from data file lines, and
4964 repeated spaces in "Rule Jordan" lines in the "asia" file have been
4968 Release 2000h - 2000-12-14 15:33:38 -0500
4970 changes by Paul Eggert
4972 one typo fix in the "art" file
4974 With providence, this is the last update of the millennium.
4977 Release 2000g - 2000-10-10 11:35:22 -0400
4979 changes by Paul Eggert
4981 correction of John Mackin's name submitted by Robert Elz
4983 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
4984 Emmy Awards broadcast.
4987 Release 2000f - 2000-08-10 09:31:58 -0400
4989 changes by Paul Eggert
4991 Added information in "tz-art.htm" on a Seinfeld reference to DST.
4993 Error checking and messages in the "yearistype" script have been
4997 Release 2000e - 2000-07-31 09:27:54 -0400
4999 data changes by Paul Eggert
5001 a change to the default value of the defined constant HAVE_STRERROR
5003 the addition of a Dave Barry quote on DST to the tz-arts file
5006 Release 2000d - 2000-04-20 15:43:04 -0400
5008 changes to the documentation and code of strftime for C99 conformance
5010 a bug fix for date.c
5012 These are based on (though modified from) changes by Paul Eggert.
5015 Release 2000c - 2000-03-04 10:31:43 -0500
5017 changes by Paul Eggert
5020 Release 2000b - 2000-02-21 12:16:29 -0500
5022 changes by Paul Eggert and Joseph Myers
5024 modest tweaks to the tz-art.htm and tz-link.htm files
5027 Release 2000a - 2000-01-18 09:21:26 -0500
5029 changes by Paul Eggert
5031 The two hypertext documents have also been renamed.
5034 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
5036 Paul Eggert's changes
5038 additions to the "zic" manual page and the "Arts.htm" file
5041 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
5046 Release data1999h - 1999-10-07 03:50:29 -0400
5048 changes by Paul Eggert to "europe" (most importantly, fixing
5049 Lithuania and Estonia)
5052 Release 1999g - 1999-09-28 11:06:18 -0400
5054 data changes by Paul Eggert (most importantly, the change for
5055 Lebanon that buys correctness for this coming Sunday)
5057 The "code" file contains changes to "Makefile" and "checktab.awk" to
5058 allow better checking of time zone files before they are published.
5061 Release 1999f - 1999-09-23 09:48:14 -0400
5063 changes by Arthur David Olson and Paul Eggert
5066 Release 1999e - 1999-08-17 15:20:54 -0400
5068 changes circulated by Paul Eggert, although the change to handling
5069 of DST-specifying timezone names has been commented out for now
5070 (search for "XXX" in "localtime.c" for details). These files also
5071 do not make any changes to the start of DST in Brazil.
5073 In addition to Paul's changes, there are updates to "Arts.htm" and
5077 Release 1999d - 1999-03-30 11:31:07 -0500
5079 changes by Paul Eggert
5081 The Makefile's "make public" rule has also been changed to do a test
5082 compile of each individual time zone data file (which should help
5083 avoid problems such as the one we had with Nicosia).
5086 Release 1999c - 1999-03-25 09:47:47 -0500
5088 changes by Paul Eggert, most importantly the change for Chile.
5091 Release 1999b - 1999-02-01 17:51:44 -0500
5093 changes by Paul Eggert
5095 code changes (suggested by Mani Varadarajan, mani at be.com) for
5096 correct handling of symbolic links when building using a relative directory
5098 code changes to generate correct messages for failed links
5100 updates to the URLs in Arts.htm
5103 Release 1999a - 1999-01-19 16:20:29 -0500
5105 error message internationalizations and corrections in zic.c and
5106 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5110 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5112 changes for Brazil, Chile, and Germany
5114 support for use of "24:00" in the input files for the time zone compiler
5117 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5119 changes by Paul Eggert
5121 correction to a define in the "private.h" file
5124 Release data1998g - 1998-08-11 03:28:35 -0000
5125 [tzdata1998g.tar.gz is missing!]
5127 Lithuanian change provided by mgedmin at pub.osf.it
5129 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5130 "backward") to ensure that the GMT file is created even where folks
5131 don't want the "backward" links (as suggested by Paul Eggert).
5134 Release data1998f - 1998-07-20 13:50:00 -0000
5135 [tzdata1998f.tar.gz is missing!]
5137 Update the "leapseconds" file to include the newly-announced
5138 insertion at the end of 1998.
5141 Release code1998f - 1998-06-01 10:18:31 -0400
5143 addition to localtime.c by Guy Harris
5146 Release 1998e - 1998-05-28 09:56:26 -0400
5148 The Makefile is changed to produce zoneinfo-posix rather than
5149 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5152 data changes by Paul Eggert
5154 changes from Guy Harris to provide asctime_r and ctime_r
5156 A usno1998 file (substantially identical to usno1997) has been added.
5159 Release 1998d - 1998-05-14 11:58:34 -0400
5161 changes to comments (in particular, elimination of references to CIA maps).
5162 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5163 where changes occur.
5166 Release 1998c - 1998-02-28 12:32:26 -0500
5168 changes by Paul Eggert (save the "French correction," on which I'll
5169 wait for the dust to settle)
5173 changes and additions to Arts.htm
5176 Release 1998b - 1998-01-17 14:31:51 -0500
5178 URL cleanups and additions
5181 Release 1998a - 1998-01-13 12:37:35 -0500
5183 changes by Paul Eggert
5186 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5188 changes by Paul Eggert, with minor modifications from Arthur David
5189 Olson to make the files more browser friendly
5192 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5194 minor changes to put "TZif" at the start of each timezone information file
5196 a rule has also been added to the Makefile so you can
5198 to just recompile the zone information files (rather than doing a
5199 full "make install" with its other effects).
5202 Release data1997i - 1997-10-07 08:45:38 -0400
5204 changes to Africa by Paul Eggert
5207 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5209 corrections for Uruguay (and other locations)
5211 Arthur David Olson's simple-minded fix allowing mktime to both
5212 correctly handle leap seconds and correctly handle tm_sec values
5213 upon which arithmetic has been performed.
5216 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5218 Paul Eggert's updates
5220 a small change to a function prototype;
5222 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5223 include information on Around the World in Eighty Days.
5226 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5228 fixes to zic's error handling
5230 changes inspired by the item circulated on Slovenia
5232 The description of Web resources has been HTMLified for browsing
5235 A new piece of tz-related music has been added to the "Music" file.
5238 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5240 Paul Eggert's latest suggestions
5243 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5245 changes to "zic.c" to correct performance of the "-s" option
5247 a new file "usno1997"
5250 Release data1997c - 1997-03-04 09:58:18 -0500
5255 Release 1997b - 1997-02-27 18:34:19 -0500
5257 The data file incorporates the 1997 leap second.
5259 The code file incorporates Arthur David Olson's take on the
5260 zic/multiprocessor/directory-creation situation.
5263 Release 1997a - 1997-01-21 09:11:10 -0500
5265 Paul Eggert's Antarctica (and other changes)
5267 Arthur David Olson finessed the "getopt" issue by checking against
5268 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5269 is returned while SunOS 5.5's manual says EOF is returned).
5272 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5274 Paul Eggert's latest changes
5277 Release code1996n - 1996-12-16 09:42:02 -0500
5279 link snapping fix from Bruce Evans (via Garrett Wollman)
5282 Release data1996m - 1996-11-24 02:37:34 -0000
5283 [tzdata1996m.tar.gz is missing!]
5285 Paul Eggert's batch of changes
5288 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5290 No functional changes here; the files have simply been changed to
5291 make more use of ISO style dates in comments. The names of the above
5292 files now include the year in full.
5295 Release code96l - 1996-09-08 17:12:20 -0400
5297 tzcode96k was missing a couple of pieces.
5300 Release 96k - 1996-09-08 16:06:22 -0400
5302 the latest round of changes from Paul Eggert
5304 the recent Year 2000 material
5307 Release code96j - 1996-07-30 13:18:53 -0400
5309 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5312 Release code96i - 1996-07-27 20:11:35 -0400
5314 Paul's suggested patch for strftime %V week numbers
5317 Release data96i - 1996-07-01 18:13:04 -0400
5319 "northamerica" and "europe" changes by Paul Eggert
5322 Release code96h - 1996-06-05 08:02:21 -0400
5324 fix for handling transitions specified in Universal Time
5326 Some "public domain" notices have also been added.
5329 Release code96g - 1996-05-16 14:00:26 -0400
5331 fix for the simultaneous-DST-and-zone-change challenge
5334 Release data96h - 1996-05-09 17:40:51 -0400
5336 changes by Paul Eggert
5339 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5340 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5342 The changes get us some of the way to fixing the problems noted in Paul
5343 Eggert's letter yesterday (in addition to a few others). The approach
5344 has been to make zic a bit smarter about figuring out what time zone
5345 abbreviations apply just after the time specified in the "UNTIL" part
5346 of a zone line. Putting the smarts in zic means avoiding having
5347 transition times show up in both "Zone" lines and "Rule" lines, which
5348 in turn avoids multiple transition time entries in time zone files.
5349 (This also makes the zic input files such as "europe" a bit shorter and
5350 should ease maintenance.)
5353 Release data96f - 1996-04-19 19:20:03 -0000
5354 [tzdata96f.tar.gz is missing!]
5356 The only changes are to the "northamerica" file; the time zone
5357 abbreviation for Denver is corrected to MST (and MDT), and the
5358 comments for Mexico have been updated.
5361 Release data96e - 1996-03-19 17:37:26 -0500
5363 Proposals by Paul Eggert, in particular the Portugal change that
5364 comes into play at the end of this month.
5367 Release data96d - 1996-03-18 20:49:39 -0500
5372 Release code96e - 1996-02-29 15:43:27 -0000
5373 [tzcode96e.tar.gz is missing!]
5375 internationalization changes and the fix to the documentation for strftime
5378 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5380 The "code" file simply updates Bob Kridle's electronic address.
5382 The "data" file updates rules for Mexico.
5385 Release data96b - 1996-01-27 15:44:42 -0500
5390 Release code96c - 1996-01-16 16:58:15 -0500
5392 leap-year streamlining and binary-search changes
5397 Release code96b - 1996-01-10 20:42:39 -0500
5399 fixes and enhancements from Paul Eggert, including code that
5400 emulates the behavior of recent versions of the SunOS "date"
5404 Release 96a - 1996-01-06 09:08:24 -0500
5408 fixes to strftime.c for correct ISO 8601 week number generation,
5409 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5410 numbers (which are not necessarily the same as calendar year numbers)
5413 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5415 The latest revisions from Paul Eggert are included, the usno1995
5416 file has been updated, and a new file ("WWW") covering useful URLs
5420 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5422 A simplification of a macro definition, a change to data for Sudan,
5423 and (for last minute shoppers) notes in the "Music" file on the CD
5427 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5429 (slightly reformatted) 8-bit-clean proposed patch
5431 minor patch: US/Eastern -> America/New_York
5433 snapshot of the USNO's latest data ("usno1995")
5435 some other minor cleanups
5438 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5439 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5443 support for 64-bit time_t's
5445 optimization in localtime.c
5448 Release code95e - 1995-10-13 13:23:57 -0400
5450 the mktime change to scan from future to past when trying to find time zone
5454 Release data95i - 1995-09-26 10:43:26 -0400
5456 For Canada/Central, guess that the Sun customer's "one week too
5457 early" was just a approximation, and the true error is one month
5458 too early. This is consistent with the rest of Canada.
5461 Release data95h - 1995-09-21 11:26:48 -0400
5463 latest changes from Paul Eggert
5466 Release code95d - 1995-09-14 11:14:45 -0400
5468 the addition of a "Music" file, which documents four recorded
5469 versions of the tune "Save That Time".
5472 Release data95g - 1995-09-01 17:21:36 -0400
5474 "yearistype" correction
5477 Release data95f - 1995-08-28 20:46:56 -0400
5479 Paul Eggert's change to the australasia file
5482 Release data95e - 1995-07-08 18:02:34 -0400
5484 The only change is a leap second at the end of this year.
5485 Thanks to Bradley White for forwarding news on the leap second.
5488 Release data95d - 1995-07-03 13:26:22 -0400
5490 Paul Eggert's changes
5493 Release data95c - 1995-07-02 19:19:28 -0400
5495 changes to "asia", "backward", "europe", and "southamerica"
5496 (read: northamericacentrics need not apply)
5499 Release code95c - 1995-03-13 14:00:46 -0500
5501 one-line fix for sign extension problems in detzcode
5504 Release 95b - 1995-03-04 11:22:38 -0500
5506 Minor changes in both:
5508 The "code" file contains a workaround for the lack of "unistd.h" in
5509 Microsoft C++ version 7.
5511 The "data" file contains a fixed "Link" for America/Shiprock.
5514 Release 94h - 1994-12-10 12:51:14 -0500
5518 * incorporate the changes to "zdump" and "date" to make changes to
5519 the "TZ" environment variable permanent;
5521 * incorporate the table changes by Paul Eggert;
5523 * include (and document) support for universal time specifications in
5524 data files - but do not (yet) include use of this feature in the
5527 Think of this as "TZ Classic" - the software has been set up not to break if
5528 universal time shows up in its input, and data entries have been
5529 left as is so as not to break existing implementations.
5532 Release data94f - 1994-08-20 12:56:09 -0400
5534 (with thanks!) the latest data updates from Paul Eggert
5537 Release data94e - 1994-06-04 13:13:53 -0400
5542 Release code94g - 1994-05-05 12:14:07 -0400
5544 fix missing "optind.c" and a reference to it in the Makefile
5547 Release code94f - 1994-05-05 13:00:33 -0000
5548 [tzcode94f.tar.gz is missing!]
5550 changes to avoid overflow in difftime, as well as changes to cope
5551 with the 52/53 challenge in strftime
5554 Release code94e - 1994-03-30 23:32:59 -0500
5556 change for the benefit of PCTS
5559 Release 94d - 1994-02-24 15:42:25 -0500
5561 Avoid clashes with POSIX semantics for zones such as GMT+4.
5563 Some other very minor housekeeping is also present.
5566 Release code94c - 1994-02-10 08:52:40 -0500
5568 Fix bug where mkdirs was broken unless you compile with
5569 -fwritable-strings (which is generally losing to do).
5572 Release 94b - 1994-02-07 10:04:33 -0500
5574 work by Paul Eggert who notes:
5576 I found another book of time zone histories by E W Whitman; it's not
5577 as extensive as Shanks but has a few goodies of its own. I used it
5578 to update the tables. I also fixed some more as a result of
5579 correspondence with Adam David and Peter Ilieve, and move some stray
5580 links from 'europe' to 'backward'. I corrected some scanning errors
5583 As far as the code goes, I fixed zic to allow years in the range
5584 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5585 And I cleaned up the zic documentation a little bit.
5588 Release data94a - 1994-02-03 08:58:54 -0500
5590 It simply incorporates the recently announced leap second into the
5594 Release 93g - 1993-11-22 17:28:27 -0500
5596 Paul Eggert has provided a good deal of historic information (based
5597 on Shanks), and there are some code changes to deal with the buglets
5598 that crawled out in dealing with the new information.
5601 Release 93f - 1993-10-15 12:27:46 -0400
5603 Paul Eggert's changes
5606 Release 93e - 1993-09-05 21:21:44 -0400
5608 This has updated data for Israel, England, and Kwajalein. There's
5609 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5610 Thanks to Paul Eggert and Peter Ilieve for the changes.
5613 Release 93d - 1993-06-17 23:34:17 -0400
5615 new fix and new data on Israel
5618 Release 93c - 1993-06-06 19:31:55 -0400
5623 Release 93b - 1993-02-02 14:53:58 -0500
5625 updated "leapseconds" file
5628 Release 93 - 1993-01-08 07:01:06 -0500
5630 At kre's suggestion, the package has been split in two - a code piece
5631 (which also includes documentation) that's only of use to folks who
5632 want to recompile things and a data piece useful to anyone who can
5635 The new version has a few changes to the data files, a few
5636 portability changes, and an off-by-one fix (with thanks to
5637 Tom Karzes at deshaw.com for providing a description and a
5641 Release 92c - 1992-11-21 17:35:36 -0000
5642 [tz92c.tar.Z is missing!]
5644 The fallout from the latest round of DST transitions.
5646 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5647 there's also a change to "zic.c" that makes it portable to more systems.
5650 Release 92 - 1992-04-25 18:17:03 -0000
5651 [tz92.tar.Z is missing!]
5653 By popular demand (well, at any rate, following a request by kre at munnari)
5656 The 1989 update of the time zone package featured:
5658 * POSIXization (including interpretation of POSIX-style TZ environment
5659 variables, provided by Guy Harris),
5660 * ANSIfication (including versions of "mktime" and "difftime"),
5661 * SVIDulation (an "altzone" variable)
5662 * MACHination (the "gtime" function)
5663 * corrections to some time zone data (including corrections to the rules
5664 for Great Britain and New Zealand)
5665 * reference data from the United States Naval Observatory for folks who
5666 want to do additional time zones
5667 * and the 1989 data for Saudi Arabia.
5669 (Since this code will be treated as "part of the implementation" in some
5670 places and as "part of the application" in others, there's no good way to
5671 name functions, such as timegm, that are not part of the proposed ANSI C
5672 standard; such functions have kept their old, underscore-free names in this
5675 And the "dysize" function has disappeared; it was present to allow
5676 compilation of the "date" command on old BSD systems, and a version of "date"
5677 is now provided in the package. The "date" command is not created when you
5678 "make all" since it may lack options provided by the version distributed with
5679 your operating system, or may not interact with the system in the same way
5680 the native version does.
5682 Since POSIX frowns on correct leap second handling, the default behavior of
5683 the "zic" command (in the absence of a "-L" option) has been changed to omit
5684 leap second information from its output files.
5690 This file contains copies of the part of each release announcement
5691 that talks about the changes in that release. The text has been
5692 adapted and reformatted for the purposes of this file.
5694 Traditionally a release R consists of a pair of tarball files,
5695 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5696 code2010a, data2012c) consist of just one or the other tarball, and a
5697 few (e.g., code2012c-data2012d) have tarballs with mixed version
5698 numbers. Recent releases also come in an experimental format
5699 consisting of a single tarball tzdb-R.tar.lz with extra data.
5701 Release timestamps are taken from the release's commit (for newer,
5702 Git-based releases), from the newest file in the tarball (for older
5703 releases, where this info is available) or from the email announcing
5704 the release (if all else fails; these are marked with a time zone
5705 abbreviation of -0000 and an "is missing!" comment).
5707 Earlier versions of the code and data were not announced on the tz
5708 list and are not summarized here.
5710 This file is in the public domain.