1 News for the tz database
3 Release 2021e - 2021-10-21 18:41:00 -0700
5 Changes to future timestamps
7 Palestine will fall back 10-29 (not 10-30) at 01:00.
8 (Thanks to P Chan and Heba Hemad.)
11 Release 2021d - 2021-10-15 13:48:18 -0700
14 Fiji suspends DST for the 2021/2022 season.
15 'zic -r' marks unspecified timestamps with "-00".
17 Changes to future timestamps
19 Fiji will suspend observance of DST for the 2021/2022 season.
20 Assume for now that it will return next year. (Thanks to Jashneel
25 'zic -r' now uses "-00" time zone abbreviations for intervals
26 with UT offsets that are unspecified due to -r truncation.
27 This implements a change in draft Internet RFC 8536bis.
30 Release 2021c - 2021-10-01 14:21:49 -0700
33 Revert most 2021b changes to 'backward'.
34 Fix 'zic -b fat' bug in pre-1970 32-bit data.
35 Fix two Link line typos.
36 Distribute SECURITY file.
38 This release is intended as a bugfix release, to fix compatibility
39 problems and typos reported since 2021b was released.
41 Changes to Link directives
43 Revert almost all of 2021b's changes to the 'backward' file,
44 by moving Link directives back to where they were in 2021a.
45 Although 'zic' doesn't care which source file contains a Link
46 directive, some downstream uses ran into trouble with the move.
47 (Problem reported by Stephen Colebourne for Joda-Time.)
49 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
50 (problem reported by Chris Walton).
52 Fix 'backzone' typo that linked America/Virgin to the wrong
53 location (problem reported by Michael Deckers).
57 Fix a bug in 'zic -b fat' that caused old timestamps to be
58 mishandled in 32-bit-only readers (problem reported by Daniel
61 Changes to documentation
63 Distribute the SECURITY file (problem reported by Andreas Radke).
66 Release 2021b - 2021-09-24 16:23:00 -0700
69 Jordan now starts DST on February's last Thursday.
70 Samoa no longer observes DST.
71 Merge more location-based Zones whose timestamps agree since 1970.
72 Move some backward-compatibility links to 'backward'.
73 Rename Pacific/Enderbury to Pacific/Kanton.
74 Correct many pre-1993 transitions in Malawi, Portugal, etc.
75 zic now creates each output file or link atomically.
76 zic -L no longer omits the POSIX TZ string in its output.
77 zic fixes for truncation and leap second table expiration.
78 zic now follows POSIX for TZ strings using all-year DST.
79 Fix some localtime crashes and bugs in obscure cases.
80 zdump -v now outputs more-useful boundary cases.
81 tzfile.5 better matches a draft successor to RFC 8536.
84 This release is prompted by recent announcements by Jordan and Samoa.
85 It incorporates many other changes that had accumulated since 2021a.
86 However, it omits most proposed changes that merged all Zones
87 agreeing since 1970, as concerns were raised about doing too many of
88 these changes at once. It does keeps some of these changes in the
89 interest of making tzdb more equitable one step at a time; see
90 "Merge more location-based Zones" below.
92 Changes to future timestamps
94 Jordan now starts DST on February's last Thursday.
95 (Thanks to Steffen Thorsen.)
97 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
101 Rename Pacific/Enderbury to Pacific/Kanton. When we added
102 Enderbury in 1993, we did not know that it is uninhabited and that
103 Kanton (population two dozen) is the only inhabited location in
104 that timezone. The old name is now a backward-compatility link.
106 Changes to past timestamps
108 Correct many pre-1993 transitions, fixing entries originally
109 derived from Shanks, Whitman, and Mundell. The fixes include:
110 - Barbados: standard time was introduced in 1911, not 1932; and
111 DST was observed in 1942-1944
112 - Cook Islands: In 1899 they switched from east to west of GMT,
113 celebrating Christmas for two days. They (and Niue) switched
114 to standard time in 1952, not 1901.
115 - Guyana: corrected LMT for Georgetown; the introduction of
116 standard time in 1911, not 1915; and corrections to 1975 and
118 - Kanton: uninhabited before 1937-08-31
119 - Niue: only observed -11:20 from 1952 through 1964, then went to
120 -11 instead of -11:30
121 - Portugal: DST was observed in 1950
122 - Tonga: corrected LMT; the introduction of standard time in 1945,
123 not 1901; and corrections to the transition from +12:20 to +13
125 Additional fixes to entries in the 'backzone' file include:
126 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
127 - The Gambia: 1933 and 1942 transitions
128 - Malawi: several 1911 through 1925 transitions
129 - Sierra Leone: several 1913 through 1941 transitions, and DST
130 was NOT observed in 1957 through 1962
131 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
134 Merge more location-based Zones whose timestamps agree since 1970,
135 as pre-1970 timestamps are out of scope. This is part of a
136 process that has been ongoing since 2013. This does not affect
137 post-1970 timestamps, and timezone historians who build with 'make
138 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
139 When merging, keep the most-populous location's data, and move
140 data for other locations to 'backzone' with a backward
141 link in 'backward'. For example, move America/Creston data to
142 'backzone' with a link in 'backward' from America/Phoenix because
143 the two timezones' timestamps agree since 1970; this change
144 affects some pre-1968 timestamps in America/Creston because
145 Creston and Phoenix disagreed before 1968. The affected Zones
146 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
147 America/Creston, America/Curacao, America/Nassau,
148 America/Port_of_Spain, Antarctica/DumontDUrville, and
151 Changes to maintenance procedure
153 The new file SECURITY covers how to report security-related bugs.
155 Several backward-compatibility links have been moved to the
156 'backward' file. These links, which range from Africa/Addis_Ababa
157 to Pacific/Saipan, are only for compatibility with now-obsolete
158 guidelines suggesting an entry for every ISO 3166 code.
159 The intercontinental convenience links Asia/Istanbul and
160 Europe/Nicosia have also been moved to 'backward'.
164 zic now creates each output file or link atomically,
165 possibly by creating a temporary file and then renaming it.
166 This avoids races where a TZ setting would temporarily stop
167 working while zic was installing a replacement file or link.
169 zic -L no longer omits the POSIX TZ string in its output.
170 Starting with 2020a, zic -L truncated its output according to the
171 "Expires" directive or "#expires" comment in the leapseconds file.
172 The resulting TZif files omitted daylight saving transitions after
173 the leap second table expired, which led to far less-accurate
174 predictions of times after the expiry. Although future timestamps
175 cannot be converted accurately in the presence of leap seconds, it
176 is more accurate to convert near-future timestamps with a few
177 seconds error than with an hour error, so zic -L no longer
178 truncates output in this way.
180 Instead, when zic -L is given the "Expires" directive, it now
181 outputs the expiration by appending a no-change entry to the leap
182 second table. Although this should work well with most TZif
183 readers, it does not conform to Internet RFC 8536 and some pickier
184 clients (including tzdb 2017c through 2021a) reject it, so
185 "Expires" directives are currently disabled by default. To enable
186 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
187 this new feature it is marked with a new TZif version number 4,
188 a format intended to be documented in a successor to RFC 8536.
190 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
191 that omits leap second information for the range LO..B when LO
192 falls between two leap seconds A and B. Instead, it generates a
193 TZif version 4 file that represents the previously-missing
196 The TZif reader now allows the leap second table to begin with a
197 correction other than -1 or +1, and to contain adjacent
198 transitions with equal corrections. This supports TZif version 4.
200 The TZif reader now lets leap seconds occur less than 28 days
201 apart. This supports possible future TZif extensions.
203 Fix bug that caused 'localtime' etc. to crash when TZ was
204 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
205 not conform to POSIX but does conform to Internet RFC 8536.
207 Fix another bug that caused 'localtime' etc. to crash when TZ was
208 set to a POSIX-conforming but unusual TZ string like
209 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
211 Fix yet another bug that caused 'localtime' etc. to mishandle slim
212 TZif files containing leap seconds after the last explicit
213 transition in the table, or when handling far-future timestamps
214 in slim TZif files lacking leap seconds.
216 Fix localtime misbehavior involving positive leap seconds.
217 This change affects only behavior for "right" system time,
218 which contains leap seconds, and only if the UT offset is
219 not a multiple of 60 seconds when a positive leap second occurs.
220 (No such timezone exists in tzdb, luckily.) Without the fix,
221 the timestamp was ambiguous during a positive leap second.
222 With the fix, any seconds occurring after a positive leap second
223 and within the same localtime minute are counted through 60, not
224 through 59; their UT offset (tm_gmtoff) is the same as before.
225 Here is how the fix affects timestamps in a timezone with UT
226 offset +01:23:45 (5025 seconds) and with a positive leap second at
227 1972-06-30 23:59:60 UTC (78796800):
229 time_t without the fix with the fix
230 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
231 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
233 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
234 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
236 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
237 civil time changes a few seconds before time_t wraps around, when
238 leap seconds are enabled.
240 Fix bug in zic -r; in some cases, the dummy time type after the
241 last time transition disagreed with the TZ string, contrary to
242 Internet RFC 8563 section 3.3.
244 Fix a bug with 'zic -r @X' when X is a negative leap second that
245 has a nonnegative correction. Without the fix, the output file
246 was truncated so that X appeared to be a positive leap second.
247 Fix a similar, even-less-likely bug when truncating at a positive
248 leap second that has a nonpositive correction.
250 zic -r now reports an error if given rolling leap seconds, as this
251 usage has never generally worked and is evidently unused.
253 zic now generates a POSIX-conforming TZ string for TZif files
254 where all-year DST is predicted for the indefinite future.
255 For example, for all-year Eastern Daylight Time, zic now generates
256 "XXX3EDT4,0/0,J365/23" where it previously generated
257 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
258 noting the possibility of POSIX conformance.)
260 zic.c no longer requires sys/wait.h (thanks to spazmodius for
261 noting it wasn't needed).
263 When reading slim TZif files, zdump no longer mishandles leap
264 seconds on the rare platforms where time_t counts leap seconds,
265 fixing a bug introduced in 2014g.
267 zdump -v now outputs timestamps at boundaries of what localtime
268 and gmtime can represent, instead of the less-useful timestamps
269 one day after the minimum and one day before the maximum.
270 (Thanks to Arthur David Olson for prototype code, and to Manuela
271 Friedrich for debugging help.)
273 zdump's -c and -t options are now consistently inclusive for the
274 lower time bound and exclusive for the upper. Formerly they were
275 inconsistent. (Confusion noted by Martin Burnicki.)
277 Changes to build procedure
279 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
280 non-POSIX hosts where malloc doesn't set errno.
281 (Problem reported by Jan Engelhardt.)
283 Changes to documentation
285 tzfile.5 better matches a draft successor to RFC 8536
286 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
289 Release 2021a - 2021-01-24 10:54:57 -0800
291 Changes to future timestamps
293 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
294 (Thanks to Steffen Thorsen.)
297 Release 2020f - 2020-12-29 00:17:46 -0800
299 Change to build procedure
301 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
302 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
305 Release 2020e - 2020-12-22 15:14:34 -0800
308 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
310 Changes to future timestamps
312 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
313 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
315 Changes to past timestamps
317 Correct many pre-1986 transitions, fixing entries originally
318 derived from Shanks. The fixes include:
319 - Australia: several 1917 through 1971 transitions
320 - The Bahamas: several 1941 through 1945 transitions
321 - Bermuda: several 1917 through 1956 transitions
322 - Belize: several 1942 through 1968 transitions
323 - Ghana: several 1915 through 1956 transitions
324 - Israel and Palestine: several 1940 through 1985 transitions
325 - Kenya and adjacent: several 1908 through 1960 transitions
326 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
327 through 1919 transitions
328 - Seychelles: the introduction of standard time in 1907, not 1906
329 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
332 Because of the Australia change, Australia/Currie (King Island) is
333 no longer needed, as it is identical to Australia/Hobart for all
334 timestamps since 1970 and was therefore created by mistake.
335 Australia/Currie has been moved to the 'backward' file and its
336 corrected data moved to the 'backzone' file.
338 Changes to past time zone abbreviations and DST flags
340 To better match legislation in Turks and Caicos, the 2015 shift to
341 year-round observance of -04 is now modeled as AST throughout before
342 returning to Eastern Time with US DST in 2018, rather than as
343 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
345 Changes to documentation
347 The zic man page now documents zic's coalescing of transitions
348 when a zone falls back just before DST springs forward.
351 Release 2020d - 2020-10-21 11:24:13 -0700
354 Palestine ends DST earlier than predicted, on 2020-10-24.
356 Changes to past and future timestamps
358 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
359 as previously predicted (thanks to Sharef Mustafa.) Its
360 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
361 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
362 its spring 2020 transition was on March 28 at 00:00, not March 27
363 (thanks to Pierre Cashon.) This affects Asia/Gaza and
364 Asia/Hebron. Assume future spring and fall transitions will be on
365 the Saturday preceding the last Sunday of March and October,
369 Release 2020c - 2020-10-16 11:15:53 -0700
372 Fiji starts DST later than usual, on 2020-12-20.
374 Changes to future timestamps
376 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
377 previously predicted. DST will still end on 2021-01-17.
378 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
379 the later-than-usual start date is a one-time departure from the
382 Changes to build procedure
384 Rearguard tarballs now contain an empty file pacificnew.
385 Some older downstream software expects this file to exist.
386 (Problem reported by Mike Cullinan.)
389 Release 2020b - 2020-10-06 18:35:04 -0700
392 Revised predictions for Morocco's changes starting in 2023.
393 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
394 Macquarie Island has stayed in sync with Tasmania since 2011.
395 Casey, Antarctica is at +08 in winter and +11 in summer.
396 zic no longer supports -y, nor the TYPE field of Rules.
398 Changes to future timestamps
400 Morocco's spring-forward after Ramadan is now predicted to occur
401 no sooner than two days after Ramadan, instead of one day.
402 (Thanks to Milamber.) The first altered prediction is for 2023,
403 now predicted to spring-forward on April 30 instead of April 23.
405 Changes to past and future timestamps
407 Casey Station, Antarctica has been using +08 in winter and +11 in
408 summer since 2018. The most recent transition from +08 to +11 was
409 2020-10-04 00:01. Also, Macquarie Island has been staying in
410 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
412 Changes to past and future time zone abbreviations and DST flags
414 Canada's Yukon, represented by America/Whitehorse and
415 America/Dawson, changes its time zone rules from -08/-07 to
416 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
417 This change affects only the time zone abbreviation (MST vs PDT)
418 and daylight saving flag for the period between the two dates.
419 (Thanks to Andrew G. Smith.)
421 Changes to past timestamps
423 Correct several transitions for Hungary for 1918/1983.
424 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
425 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
426 time was on 11-01, not 10-01 (thanks to Michael Deckers).
428 The 1891 French transition was on March 16, not March 15. The
429 1911-03-11 French transition was at midnight, not a minute later.
430 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
431 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
435 Support for zic's long-obsolete '-y YEARISTYPE' option has been
436 removed and, with it, so has support for the TYPE field in Rule
437 lines, which is now reserved for compatibility with earlier zic.
438 These features were previously deprecated in release 2015f.
439 (Thanks to Tim Parenti.)
441 zic now defaults to '-b slim' instead of to '-b fat'.
443 zic's new '-l -' and '-p -' options uninstall any existing
444 localtime and posixrules files, respectively.
446 The undocumented and ineffective tzsetwall function has been
449 Changes to build procedure
451 The Makefile now defaults POSIXRULES to '-', so the posixrules
452 feature (obsolete as of 2019b) is no longer installed by default.
454 Changes to documentation and commentary
456 The long-obsolete files pacificnew, systemv, and yearistype.sh have
457 been removed from the distribution. (Thanks to Tim Parenti.)
460 Release 2020a - 2020-04-23 16:03:47 -0700
463 Morocco springs forward on 2020-05-31, not 2020-05-24.
464 Canada's Yukon advanced to -07 year-round on 2020-03-08.
465 America/Nuuk renamed from America/Godthab.
466 zic now supports expiration dates for leap second lists.
468 Changes to future timestamps
470 Morocco's second spring-forward transition in 2020 will be May 31,
471 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
472 Adjust future-year predictions to use the first Sunday after the
473 day after Ramadan, not the first Sunday after Ramadan.
475 Canada's Yukon, represented by America/Whitehorse and
476 America/Dawson, advanced to -07 year-round, beginning with its
477 spring-forward transition on 2020-03-08, and will not fall back on
478 2020-11-01. Although a government press release calls this
479 "permanent Pacific Daylight Saving Time", we prefer MST for
480 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
481 (Thanks to Tim Parenti.)
483 Changes to past timestamps
485 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
487 Changes to timezone identifiers
489 To reflect current usage in English better, America/Godthab has
490 been renamed to America/Nuuk. A backwards-compatibility link
491 remains for the old name.
495 localtime.c no longer mishandles timestamps after the last
496 transition in a TZif file with leap seconds and with daylight
497 saving time transitions projected into the indefinite future.
498 For example, with TZ='America/Los_Angeles' with leap seconds,
499 zdump formerly reported a DST transition on 2038-03-14
500 from 01:59:32.999... to 02:59:33 instead of the correct transition
501 from 01:59:59.999... to 03:00:00.
503 zic -L now supports an Expires line in the leapseconds file, and
504 truncates the TZif output accordingly. This propagates leap
505 second expiration information into the TZif file, and avoids the
506 abovementioned localtime.c bug as well as similar bugs present in
507 many client implementations. If no Expires line is present, zic
508 -L instead truncates the TZif output based on the #expires comment
509 present in leapseconds files distributed by tzdb 2018f and later;
510 however, this usage is obsolescent. For now, the distributed
511 leapseconds file has an Expires line that is commented out, so
512 that the file can be fed to older versions of zic which ignore the
513 commented-out line. Future tzdb distributions are planned to
514 contain a leapseconds file with an Expires line.
516 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
517 set to 1 if the system library supports the feature, and 2 if not.
518 As before, these macros are nonzero if tzcode should support the
519 feature, zero otherwise.
521 The configuration macro ALTZONE now has the same values with the
522 same meaning as HAVE_TZNAME and USG_COMPAT.
524 The code's defense against CRLF in leap-seconds.list is now
525 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
527 Although the undocumented tzsetwall function is not changed in
528 this release, it is now deprecated in preparation for removal in
529 future releases. Due to POSIX requirements, tzsetwall has not
530 worked for some time. Any code that uses it should instead use
531 tzalloc(NULL) or, if portability trumps thread-safety, should
532 unset the TZ environment variable.
534 Changes to commentary
536 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
537 following America/Halifax, and comments about Yukon's "south" and
538 "north" have been corrected to say "east" and "west". (Thanks to
542 Release 2019c - 2019-09-11 08:59:48 -0700
545 Fiji observes DST from 2019-11-10 to 2020-01-12.
546 Norfolk Island starts observing Australian-style DST.
548 Changes to future timestamps
550 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
551 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
552 Adjust future guesses accordingly.
554 Norfolk Island will observe Australian-style DST starting in
555 spring 2019. The first transition is on 2019-10-06. (Thanks to
556 Kyle Czech and Michael Deckers.)
558 Changes to past timestamps
560 Many corrections to time in Turkey from 1940 through 1985.
561 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
563 The Norfolk Island 1975-03-02 transition was at 02:00 standard
564 time, not 02:00 DST. (Thanks to Michael Deckers.)
566 South Korea observed DST from 1948 through 1951. Although this
567 info was supposed to appear in release 2014j, a typo inadvertently
568 suppressed the change. (Thanks to Alois Treindl.)
570 Detroit observed DST in 1967 and 1968 following the US DST rules,
571 except that its 1967 DST began on June 14 at 00:01. (Thanks to
572 Alois Treindl for pointing out that the old data entries were
575 Fix several errors in pre-1970 transitions in Perry County, IN.
576 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
578 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
579 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
580 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
581 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
582 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
583 Königsberg switched to +03 on 04-07 not 01-01.
585 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
586 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
587 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
589 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
590 (Thanks to Michael Deckers.)
592 Changes to past time zone abbreviations and DST flags
594 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
595 is now flagged as DST and is abbreviated HKWT not HKT.
599 leapseconds.awk now relies only on its input data, rather than
600 also relying on its comments. (Inspired by code from Dennis
601 Ferguson and Chris Woodbury.)
603 The code now defends against CRLFs in leap-seconds.list.
604 (Thanks to Brian Inglis and Chris Woodbury.)
606 Changes to documentation and commentary
608 theory.html discusses leap seconds. (Thanks to Steve Summit.)
610 Nashville's newspapers dueled about the time of day in the 1950s.
611 (Thanks to John Seigenthaler.)
613 Liechtenstein observed Swiss DST in 1941/2.
614 (Thanks to Alois Treindl.)
617 Release 2019b - 2019-07-01 00:09:53 -0700
620 Brazil no longer observes DST.
621 'zic -b slim' outputs smaller TZif files; please try it out.
622 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
624 Changes to future timestamps
626 Brazil has canceled DST and will stay on standard time indefinitely.
627 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
630 Predictions for Morocco now go through 2087 instead of 2037, to
631 work around a problem on newlib when using TZif files output by
632 zic 2019a or earlier. (Problem reported by David Gauchard.)
634 Changes to past and future timestamps
636 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
637 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
638 future transitions to be March's last Friday at 00:00.
640 Changes to past timestamps
642 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
643 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
644 not 09-15 at 00:00. In 1946 its spring-forward transition was on
645 04-21 at 00:00, not the previous day at 03:30. From 1946 through
646 1952 its fall-back transitions occurred at 04:30, not at 03:30.
647 In 1947 its fall-back transition was on 11-30, not 12-30.
650 Changes to past time zone abbreviations
652 Italy's 1866 transition to Rome Mean Time was on December 12, not
653 September 22. This affects only the time zone abbreviation for
654 Europe/Rome between those dates. (Thanks to Stephen Trainor and
657 Changes affecting metadata only
659 Add info about the Crimea situation in zone1970.tab and zone.tab.
660 (Problem reported by Serhii Demediuk.)
664 zic's new -b option supports a way to control data bloat and to
665 test for year-2038 bugs in software that reads TZif files.
666 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
667 for example, changing from fat to slim shrinks the Europe/London
668 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
669 files represent the same set of timestamps and use the same TZif
670 format as documented in tzfile(5) and in Internet RFC 8536.
671 Fat format attempts to work around bugs or incompatibilities in
672 older software, notably software that mishandles 64-bit TZif data
673 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
674 Slim format is more efficient and does not work around 64-bit bugs
675 or obsolete TZ strings. Currently zic defaults to fat format
676 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
677 out-of-the-box default is intended to change in future releases
678 as the buggy software often mishandles timestamps anyway.
680 zic no longer treats a set of rules ending in 2037 specially.
681 Previously, zic assumed that such a ruleset meant that future
682 timestamps could not be predicted, and therefore omitted a
683 POSIX-like TZ string in the TZif output. The old behavior is no
684 longer needed for current tzdata, and caused problems with newlib
685 when used with older tzdata (reported by David Gauchard).
687 zic no longer generates some artifact transitions. For example,
688 Europe/London no longer has a no-op transition in January 1996.
690 Changes to build procedure
692 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
695 Changes to documentation and commentary
697 The Makefile now documents the POSIXRULES macro as being obsolete,
698 and similarly, zic's -p POSIXRULES option is now documented as
699 being obsolete. Although the POSIXRULES feature still exists and
700 works as before, in practice it is rarely used for its intended
701 purpose, and it does not work either in the default reference
702 implementation (for timestamps after 2037) or in common
703 implementations such as GNU/Linux (for contemporary timestamps).
704 Since POSIXRULES was designed primarily as a temporary transition
705 facility for System V platforms that died off decades ago, it is
706 being decommissioned rather than institutionalized.
708 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
711 Release 2019a - 2019-03-25 22:01:33 -0700
714 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
715 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
717 Changes to past and future timestamps
719 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
720 previously predicted. Adjust our prediction by guessing that spring
721 transitions will be between 24 and 30 March, which matches recent practice
722 since 2016. (Thanks to Even Scharning and Tim Parenti.)
724 Metlakatla ended its observance of Pacific standard time,
725 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
726 Stanley and Tim Parenti.)
728 Changes to past timestamps
730 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
731 (Thanks to Alois Treindl and Isaac Starkman.)
733 Changes to time zone abbreviations
735 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
736 of being a separate zone that generates the abbreviation "UCT",
737 which nowadays is typically a typo. (Problem reported by Isiah
742 zic now has an -r option to limit the time range of output data.
743 For example, 'zic -r @1000000000' limits the output data to
744 timestamps starting 1000000000 seconds after the Epoch.
745 This helps shrink output size and can be useful for applications
746 not needing the full timestamp history, such as TZDIST truncation;
747 see Internet RFC 8536 section 5.1. (Inspired by a feature request
748 from Christopher Wong, helped along by bug reports from Wong and
751 Changes to documentation
753 Mention Internet RFC 8536 (February 2019), which documents TZif.
755 tz-link.html now cites tzdata-meta
756 <https://tzdata-meta.timtimeonline.com/>.
759 Release 2018i - 2018-12-30 11:05:43 -0800
762 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
764 Changes to future timestamps
766 Due to a change in government, São Tomé and Príncipe switches back
767 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
768 Nasardinov and Michael Deckers.)
771 Release 2018h - 2018-12-23 17:59:32 -0800
774 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
775 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
776 Metlakatla, Alaska observes PST this winter only.
777 Guess Morocco will continue to adjust clocks around Ramadan.
778 Add predictions for Iran from 2038 through 2090.
780 Changes to future timestamps
782 Guess that Morocco will continue to fall back just before and
783 spring forward just after Ramadan, the practice since 2012.
784 (Thanks to Maamar Abdelkader.) This means Morocco will observe
785 negative DST during Ramadan in main and vanguard formats, and in
786 rearguard format it stays in the +00 timezone and observes
787 ordinary DST in all months other than Ramadan. As before, extend
788 this guesswork to the year 2037. As a consequence, Morocco is
789 scheduled to observe three DST transitions in some Gregorian years
790 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
793 The table of exact transitions for Iranian DST has been extended.
794 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
795 It now cuts off before 2091 as there is doubt about how the Persian
796 calendar will treat 2091. This change predicts DST transitions in
797 2038-9, 2042-3, and 2046-7 to occur one day later than previously
798 predicted. As before, post-cutoff transitions are approximated.
800 Changes to past and future timestamps
802 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
803 +05 on 2018-12-21. This is a zone split as Qostanay (aka
804 Kostanay) did not switch, so create a zone Asia/Qostanay.
806 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
807 It did not change clocks that day and remains on -08 this winter.
808 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
809 rules next spring, so this change affects only timestamps
810 from 2018-11-04 through 2019-03-10.
812 Change to past timestamps
814 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
815 not 00:00. I transcribed the time incorrectly from Shanks.
816 (Thanks to Phake Nick.)
818 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
819 (Thanks to Phake Nick.)
821 Guam observed DST irregularly from 1959 through 1977.
822 (Thanks to Phake Nick.)
824 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
825 10-01 changed standard time to +08:30 (not +08). Its transition
826 back to +08 after WWII was on 1945-09-15, not the previous day.
827 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
828 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
829 its 1952 fallback was on 11-02 (not 10-25).
831 This release contains many changes to timestamps before 1946 due
832 to Japanese possession or occupation of Pacific/Chuuk,
833 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
834 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
835 (Thanks to Phake Nick.)
837 Assume that the Spanish East Indies was like the Philippines and
838 observed American time until the end of 1844. This affects
839 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
841 Changes to past tm_isdst flags
843 For the recent Morocco change, the tm_isdst flag should be 1 from
844 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
845 Give a URL to the official decree. (Thanks to Matt Johnson.)
848 Release 2018g - 2018-10-26 22:22:45 -0700
851 Morocco switches to permanent +01 on 2018-10-28.
853 Changes to future timestamps
855 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
856 so its clocks will not fall back as previously scheduled.
857 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
861 When generating TZif files with leap seconds, zic no longer uses a
862 format that trips up older 32-bit clients, fixing a bug introduced
863 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
864 for QTBUG-53071 now also works for TZif files with leap seconds.
866 The translator to rearguard format now rewrites the line
867 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
868 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
869 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
870 and earlier. (Reported by Christos Zoulas.)
872 Changes to past time zone abbreviations
874 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
875 This reverts to 2011h, as the abbreviation change in 2011i was
878 Changes to documentation
880 tzfile.5 has new sections on interoperability issues.
883 Release 2018f - 2018-10-18 00:14:18 -0700
886 Volgograd moves from +03 to +04 on 2018-10-28.
887 Fiji ends DST 2019-01-13, not 2019-01-20.
888 Most of Chile changes DST dates, effective 2019-04-06.
890 Changes to future timestamps
892 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
893 (Thanks to Alexander Fetisov and Stepan Golosunov.)
895 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
896 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
899 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
900 time, and resume DST on the first Saturday in September at 24:00 mainland
901 time. The changes are effective from 2019-04-06, and do not affect the
902 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
903 and Tim Parenti.) Adjust future predictions accordingly.
905 Changes to past timestamps
907 The 2018-05-05 North Korea 30-minute time zone change took place
908 at 23:30 the previous day, not at 00:00 that day.
910 China's 1988 spring-forward transition was on April 17, not
911 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
914 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
915 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
916 temporarily switched to +09/+10 during World War II. Macau
917 observed DST in 1942/79, not 1961/80, and there were several
918 errors for transition times and dates. (Thanks to P Chan.)
920 The 1948-1951 fallback transitions in Japan were at 25:00 on
921 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
922 zic turns this into 01:00 on the day after September's second
923 Saturday, which is the best that POSIX or C platforms can do.
925 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
926 paper by Li Yu, replacing more-questionable data from Shanks.
928 Changes to time zone abbreviations
930 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
934 zic now always generates TZif files where time type 0 is used for
935 timestamps before the first transition. This simplifies the
936 reading of TZif files and should not affect behavior of existing
937 TZif readers because the same set of time types is used; only
938 their internal indexes may have changed. This affects only the
939 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
940 EET, which previously used nonzero types for these timestamps.
942 Because of the type 0 change, zic no longer outputs a dummy
943 transition at time -2**59 (before the Big Bang), as clients should
944 no longer need this to handle historical timestamps correctly.
945 This reverts a change introduced in 2013d and shrinks most TZif
946 files by a few bytes.
948 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
949 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
950 occurs at 18:00 on the Saturday before the last Sunday in April.
951 This behavior was documented in 2018a but the code did not
952 entirely match the documentation.
954 localtime.c no longer requires at least one time type in TZif
955 files that lack transitions or have a POSIX-style TZ string. This
956 future-proofs the code against possible future extensions to the
957 format that would allow TZif files with POSIX-style TZ strings and
958 without transitions or time types.
960 A read-access subscript error in localtime.c has been fixed.
961 It could occur only in TZif files with timecnt == 0, something that
962 does not happen in practice now but could happen in future versions.
964 localtime.c no longer ignores TZif POSIX-style TZ strings that
965 specify only standard time. Instead, these TZ strings now
966 override the default time type for timestamps after the last
967 transition (or for all timestamps if there are no transitions),
968 just as DST strings specifying DST have always done.
970 leapseconds.awk now outputs "#updated" and "#expires" comments,
971 and supports leap seconds at the ends of months other than June
972 and December. (Inspired by suggestions from Chris Woodbury.)
974 Changes to documentation
976 New restrictions: A Rule name must start with a character that
977 is neither an ASCII digit nor "-" nor "+", and an unquoted name
978 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
979 The latter restriction makes room for future extensions (a
980 possibility noted by Tom Lane).
982 tzfile.5 now documents what time types apply before the first and
983 after the last transition, if any.
985 Documentation now uses the spelling "timezone" for a TZ setting
986 that determines timestamp history, and "time zone" for a
987 geographic region currently sharing the same standard time.
989 The name "TZif" is now used for the tz binary data format.
991 tz-link.htm now mentions the A0 TimeZone Migration utilities.
992 (Thanks to Aldrin Martoq for the link.)
994 Changes to build procedure
996 New 'make' target 'rearguard_tarballs' to build the rearguard
997 tarball only. This is a convenience on platforms that lack lzip
998 if you want to build the rearguard tarball. (Problem reported by
1001 tzdata.zi is now more stable from release to release. (Problem
1002 noted by Tom Lane.) It is also a bit shorter.
1004 tzdata.zi now can contain comment lines documenting configuration
1005 information, such as which data format was selected, which input
1006 files were used, and how leap seconds are treated. (Problems
1007 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1008 are used these comment lines are absent, for backward
1009 compatibility. A redistributor intending to alter its copy of the
1010 files should also append "-LABEL" to the 'version' file's first
1011 line, where "LABEL" identifies the redistributor's change.
1014 Release 2018e - 2018-05-01 23:42:51 -0700
1018 North Korea switches back to +09 on 2018-05-05.
1019 The main format uses negative DST again, for Ireland etc.
1020 'make tarballs' now also builds a rearguard tarball.
1021 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1023 Changes to past and future timestamps
1025 North Korea switches back from +0830 to +09 on 2018-05-05.
1026 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1029 Bring back the negative-DST changes of 2018a, except be more
1030 compatible with data parsers that do not support negative DST.
1031 Also, this now affects historical timestamps in Namibia and the
1032 former Czechoslovakia, not just Ireland. The main format now uses
1033 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1034 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1035 does not affect UT offsets, only time zone abbreviations and the
1036 tm_isdst flag. Also, this does not affect rearguard or vanguard
1037 formats; effectively the main format now uses vanguard instead of
1038 rearguard format. Data parsers that do not support negative DST
1039 can still use data from the rearguard tarball described below.
1041 Changes to build procedure
1043 The command 'make tarballs' now also builds the tarball
1044 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1045 except that it uses rearguard format intended for trailing-edge
1048 Changes to data format and to code
1050 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1051 suffix, which specifies whether the adjusted time is standard time
1052 or daylight saving time. If no suffix is given, daylight saving
1053 time is used if and only if the SAVE column is nonzero; this is
1054 the longstanding behavior. Although this new feature is not used
1055 in tzdata, it could be used to specify the legal time in Namibia
1056 1994-2017, as opposed to the popular time (see below).
1058 Changes to past timestamps
1060 From 1994 through 2017 Namibia observed DST in winter, not summer.
1061 That is, it used negative DST, as Ireland still does. This change
1062 does not affect UTC offsets; it affects only the tm_isdst flag and
1063 the abbreviation used during summer, which is now CAT, not WAST.
1064 Although (as noted by Michael Deckers) summer and winter time were
1065 both simply called "standard time" in Namibian law, in common
1066 practice winter time was considered to be DST (as noted by Stephen
1067 Colebourne). The full effect of this change is only in vanguard
1068 and main format; in rearguard format, the tm_isdst flag is still
1069 zero in winter and nonzero in summer.
1071 In 1946/7 Czechoslovakia also observed negative DST in winter.
1072 The full effect of this change is only in vanguard and main
1073 formats; in rearguard format, it is modeled as plain GMT without
1074 daylight saving. Also, the dates of some 1944/5 DST transitions
1075 in Czechoslovakia have been changed.
1078 Release 2018d - 2018-03-22 07:05:46 -0700
1082 Palestine starts DST a week earlier in 2018.
1083 Add support for vanguard and rearguard data consumers.
1084 Add subsecond precision to source data format, though not to data.
1086 Changes to future timestamps
1088 In 2018, Palestine starts DST on March 24, not March 31.
1089 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1091 Changes to past and future timestamps
1093 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1094 at 04:00. (Thanks to Steffen Thorsen.)
1096 Changes to past timestamps
1098 Historical transitions for Uruguay, represented by
1099 America/Montevideo, have been updated per official legal documents,
1100 replacing previous data mainly originating from the inventions of
1101 Shanks & Pottenger. This has resulted in adjustments ranging from
1102 30 to 90 minutes in either direction over at least two dozen
1103 distinct periods ranging from one day to several years in length.
1104 A mere handful of pre-1991 transitions are unaffected; data since
1105 then has come from more reliable contemporaneous reporting. These
1106 changes affect various timestamps in 1920-1923, 1936, 1939,
1107 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1108 Additionally, Uruguay's pre-standard-time UT offset has been
1109 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1110 match the location of the Observatory of the National Meteorological
1111 Institute in Montevideo.
1112 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1114 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1115 (Thanks to Kerry Shetline.)
1117 Fix the 1912-01-01 transition for Portugal and its colonies.
1118 This transition was at 00:00 according to the new UT offset, not
1119 according to the old one. Also assume that Cape Verde switched on
1120 the same date as the rest, not in 1907. This affects
1121 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1122 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1123 (Thanks to Michael Deckers.)
1125 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1128 Changes to past time zone abbreviations
1130 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1131 is no clock change associated with the transition.
1133 Changes to build procedure
1135 The new DATAFORM macro in the Makefile lets the installer choose
1136 among three source data formats. The idea is to lessen downstream
1137 disruption when data formats are improved.
1139 * DATAFORM=vanguard installs from the latest, bleeding-edge
1140 format. DATAFORM=main (the default) installs from the format
1141 used in the 'africa' etc. files. DATAFORM=rearguard installs
1142 from a trailing-edge format. Eventually, elements of today's
1143 vanguard format should move to the main format, and similarly
1144 the main format's features should eventually move to the
1147 * In the current version, the main and rearguard formats are
1148 identical and match that of 2018c, so this change does not
1149 affect default behavior. The vanguard format currently contains
1150 one feature not in the main format: negative SAVE values. This
1151 improves support for Ireland, which uses Irish Standard Time
1152 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1153 supported negative SAVE values for decades, and this feature
1154 should move to the main format soon. However, it will not move
1155 to the rearguard format for quite some time because some
1156 downstream parsers do not support it.
1158 * The build procedure constructs three files vanguard.zi, main.zi,
1159 and rearguard.zi, one for each format. Although the files
1160 represent essentially the same data, they may have minor
1161 discrepancies that users are not likely to notice. The files
1162 are intended for downstream data consumers and are not
1163 installed. Zoneinfo parsers that do not support negative SAVE values
1164 should start using rearguard.zi, so that they will be unaffected
1165 when the negative-DST feature moves from vanguard to main.
1166 Bleeding-edge Zoneinfo parsers that support the new features
1167 already can use vanguard.zi; in this respect, current tzcode is
1170 The Makefile should now be safe for parallelized builds, and 'make
1171 -j to2050new.tzs' is now much faster on a multiprocessor host
1174 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1175 prepends TZDIR/ to file names that do not begin with '/'. This is
1176 not recommended for general use, due to its security implications.
1177 (From a suggestion by Manuela Friedrich.)
1181 zic now accepts subsecond precision in expressions like
1182 00:19:32.13, which is approximately the legal time of the
1183 Netherlands from 1835 to 1937. However, because it is
1184 questionable whether the few recorded uses of non-integer offsets
1185 had subsecond precision in practice, there are no plans for tzdata
1186 to use this feature. (Thanks to Steve Allen for pointing out
1187 the limitations of historical data in this area.)
1189 The code is a bit more portable to MS-Windows. Installers can
1190 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1191 reserve identifiers like 'localtime'. (Thanks to Manuela
1194 Changes to documentation and commentary
1196 theory.html now outlines tzdb's extensions to POSIX's model for
1197 civil time, and has a section "POSIX features no longer needed"
1198 that lists POSIX API components that are now vestigial.
1199 (From suggestions by Steve Summit.) It also better distinguishes
1200 time zones from tz regions. (From a suggestion by Guy Harris.)
1202 Commentary is now more consistent about using the phrase "daylight
1203 saving time", to match the C name tm_isdst. Daylight saving time
1204 need not occur in summer, and need not have a positive offset from
1207 Commentary about historical transitions in Uruguay has been expanded
1208 with links to many relevant legal documents.
1209 (Thanks to Tim Parenti.)
1211 Commentary now uses some non-ASCII characters with Unicode value
1212 less than U+0100, as they can be useful and should work even with
1213 older editors such as XEmacs.
1216 Release 2018c - 2018-01-22 23:00:44 -0800
1219 Revert Irish changes that relied on negative SAVE values.
1223 Revert the 2018a change to Europe/Dublin. As before, this change
1224 does not affect UT offsets or abbreviations; it affects only
1225 whether timestamps are considered to be standard time or
1226 daylight-saving time, as expressed in the tm_isdst flag of C's
1227 struct tm type. This reversion is intended to be a temporary
1228 workaround for problems discovered with downstream uses of
1229 releases 2018a and 2018b, which implemented Irish time by using
1230 negative SAVE values in the Eire rules of the 'europe' file.
1231 Although negative SAVE values have been part of tzcode for many
1232 years and are supported by many platforms, they were not
1233 documented before 2018a and ICU and OpenJDK do not currently
1234 support them. A mechanism to export data to platforms lacking
1235 support for negative DST is planned to be developed before the
1236 change is reapplied. (Problems reported by Deborah Goldsmith and
1237 Stephen Colebourne.)
1239 Changes to past timestamps
1241 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1242 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1244 Changes to build procedure
1246 The build procedure now works around mawk 1.3.3's lack of support
1247 for character class expressions. (Problem reported by Ohyama.)
1250 Release 2018b - 2018-01-17 23:24:48 -0800
1253 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1255 Changes to build procedure
1257 The distribution now contains the file 'pacificnew' again.
1258 This file was inadvertantly omitted in the 2018a distribution.
1259 (Problem reported by Matias Fonzo.)
1262 Release 2018a - 2018-01-12 22:29:21 -0800
1265 São Tomé and Príncipe switched from +00 to +01.
1266 Brazil's DST will now start on November's first Sunday.
1267 Ireland's standard time is now in the summer, not the winter.
1268 Use Debian-style installation locations, instead of 4.3BSD-style.
1271 Changes to past and future timestamps
1273 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1274 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1276 Changes to future timestamps
1278 Starting in 2018 southern Brazil will begin DST on November's
1279 first Sunday instead of October's third Sunday. (Thanks to
1282 Changes to past timestamps
1284 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1285 been corrected. The 'backzone' and 'zone.tab' files did not agree
1286 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1289 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1290 BST instead of BOST, to be more consistent with the convention
1291 used for Latvian Summer Time (1918-9) and for British Summer Time.
1295 Change Europe/Dublin so that it observes Irish Standard Time (UT
1296 +01) in summer and GMT (as negative daylight-saving) in winter,
1297 instead of observing standard time (GMT) in winter and Irish
1298 Summer Time (UT +01) in summer. This change does not affect UT
1299 offsets or abbreviations; it affects only whether timestamps are
1300 considered to be standard time or daylight-saving time, as
1301 expressed in the tm_isdst flag of C's struct tm type.
1302 (Discrepancy noted by Derick Rethans.)
1304 Changes to build procedure
1306 The default installation locations have been changed to mostly
1307 match Debian circa 2017, instead of being designed as an add-on to
1308 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1309 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1310 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1311 locations more precisely. (This responds to suggestions from
1312 Brian Inglis and from Steve Summit.)
1314 The default installation procedure no longer creates the
1315 backward-compatibility link US/Pacific-New, which causes
1316 confusion during user setup (e.g., see Debian bug 815200).
1317 Use 'make BACKWARD="backward pacificnew"' to create the link
1318 anyway, for now. Eventually we plan to remove the link entirely.
1320 tzdata.zi now contains a version-number comment.
1321 (Suggested by Tom Lane.)
1323 The Makefile now quotes values like BACKWARD more carefully when
1324 passing them to the shell. (Problem reported by Zefram.)
1326 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1327 that have snprintf and use pre-C99 compilers. (Problem reported
1332 zic has a new option -t FILE that specifies the location of the
1333 file that determines local time when TZ is unset. The default for
1334 this location can be configured via the new TZDEFAULT makefile
1335 macro, which defaults to /etc/localtime.
1337 Diagnostics and commentary now distinguish UT from UTC more
1338 carefully; see theory.html for more information about UT vs UTC.
1340 zic has been ported to GCC 8's -Wstringop-truncation option.
1341 (Problem reported by Martin Sebor.)
1343 Changes to documentation and commentary
1345 The zic man page now documents the longstanding behavior that
1346 times and years can be out of the usual range, with negative times
1347 counting backwards from midnight and with year 0 preceding year 1.
1348 (Problem reported by Michael Deckers.)
1350 The theory.html file now mentions the POSIX limit of six chars
1351 per abbreviation, and lists alphabetic abbreviations used.
1353 The files tz-art.htm and tz-link.htm have been renamed to
1354 tz-art.html and tz-link.html, respectively, for consistency with
1355 other file names and to simplify web server configuration.
1358 Release 2017c - 2017-10-20 14:49:34 -0700
1361 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1362 Fiji ends DST 2018-01-14, not 2018-01-21.
1363 Namibia switches from +01/+02 to +02 on 2018-04-01.
1364 Sudan switches from +03 to +02 on 2017-11-01.
1365 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1366 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1367 A new file tzdata.zi now holds a small text copy of all data.
1368 The zic input format has been regularized slightly.
1370 Changes to future timestamps
1372 Northern Cyprus has decided to resume EU rules starting
1373 2017-10-29, thus reinstituting winter time.
1375 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1376 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1379 Namibia will switch from +01 with DST to +02 all year on
1380 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1381 at 02:00. (Thanks to Steffen Thorsen.)
1383 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1384 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1385 Africa/Juba is no longer a link to Africa/Khartoum.
1387 Tonga has likely ended its experiment with DST, and will not
1388 adjust its clocks on 2017-11-05. Although Tonga has not announced
1389 whether it will continue to observe DST, the IATA is assuming that
1390 it will not. (Thanks to David Wade.)
1392 Turks & Caicos will switch from -04 all year to -05 with US DST on
1393 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1394 at 02:00. (Thanks to Steffen Thorsen.)
1396 Changes to past timestamps
1398 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1399 (Thanks to Arthur David Olson.)
1401 Detroit did not observe DST in 1967.
1403 Use railway time for Asia/Kolkata before 1941, by switching to
1404 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1405 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1407 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1408 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1410 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1411 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1413 Adjust the 1867 transition in Alaska to better reflect the
1414 historical record, by changing it to occur on 1867-10-18 at 15:30
1415 Sitka time rather than at the start of 1867-10-17 local time.
1416 Although strictly speaking this is accurate only for Sitka,
1417 the rest of Alaska's blanks need to be filled in somehow.
1419 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1420 (Thanks to Michael Deckers.)
1422 Add 7 s to the UT offset in Asia/Yangon before 1920.
1424 Changes to zone names
1426 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1427 exceeded the 14-character limit and was an unused misnomer anyway.
1429 Changes to build procedure
1431 To support applications that prefer to read time zone data in text
1432 form, two zic input files tzdata.zi and leapseconds are now
1433 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1434 leapseconds tzdata.zi' can reproduce the tzdata binary files
1435 without and with leap seconds, respectively. To prevent these two
1436 new files from being installed, use 'make TZDATA_TEXT=', and to
1437 suppress leap seconds from the tzdata text installation, use 'make
1438 TZDATA_TEXT=tzdata.zi'.
1440 'make BACKWARD=' now suppresses backward-compatibility names
1441 like 'US/Pacific' that are defined in the 'backward' and
1444 'make check' now works on systems that lack a UTF-8 locale,
1445 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1446 the name of a UTF-8 locale, if you have one.
1448 Y2K runtime checks are no longer enabled by default. Add
1449 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1450 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1451 to disable them. (New name suggested by Brian Inglis.)
1453 The build procedure for zdump now works on AIX 7.1.
1454 (Problem reported by Kees Dekker.)
1458 zic and the reference runtime now reject multiple leap seconds
1459 within 28 days of each other, or leap seconds before the Epoch.
1460 As a result, support for double leap seconds, which was
1461 obsolescent and undocumented, has been removed. Double leap
1462 seconds were an error in the C89 standard; they have never existed
1463 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1464 noticing glitches in the code that uncovered this problem.)
1466 zic now warns about use of the obsolescent and undocumented -y
1467 option, and about use of the obsolescent TYPE field of Rule lines.
1469 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1470 weekdays; formerly it rejected them due to a bug. Conversely, zic
1471 no longer considers non-prefixes to be abbreviations; for example,
1472 it no longer accepts "lF" as an abbreviation for "lastFriday".
1473 Also, zic warns about the undocumented usage with a "last-"
1474 prefix, e.g., "last-Fri".
1476 Similarly, zic now accepts the unambiguous abbreviation "L" for
1477 "Link" in ordinary context and for "Leap" in leap-second context.
1478 Conversely, zic no longer accepts non-prefixes such as "La" as
1479 abbreviations for words like "Leap".
1481 zic no longer accepts leap second lines in ordinary input, or
1482 ordinary lines in leap second input. Formerly, zic sometimes
1483 warned about this undocumented usage and handled it incorrectly.
1485 The new macro HAVE_TZNAME governs whether the tzname external
1486 variable is exported, instead of USG_COMPAT. USG_COMPAT now
1487 governs only the external variables "timezone" and "daylight".
1488 This change is needed because the three variables are not in the
1489 same category: although POSIX requires tzname, it specifies the
1490 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
1491 if not defined, the code attempts to guess it from other macros.
1493 localtime.c and difftime.c no longer require stdio.h, and .c files
1494 other than zic.c no longer require sys/wait.h.
1496 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
1498 Calculation of time_t extrema works around a bug in GCC 4.8.4
1499 (Reported by Stan Shebs and Joseph Myers.)
1501 zic.c no longer mistranslates formats of line numbers in non-English
1502 locales. (Problem reported by Benno Schulenberg.)
1504 Several minor changes have been made to the code to make it a
1505 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
1506 Dekker for reporting the problems.)
1508 Changes to documentation and commentary
1510 The two new files 'theory.html' and 'calendars' contain the
1511 contents of the removed file 'Theory'. The goal is to document
1512 tzdb theory more accessibly.
1514 The zic man page now documents abbreviation rules.
1516 tz-link.htm now covers how to apply tzdata changes to clients.
1517 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
1519 The leap-seconds.list URL has been updated to something that is
1520 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
1522 Release 2017b - 2017-03-17 07:30:38 -0700
1524 Briefly: Haiti has resumed DST.
1526 Changes to past and future timestamps
1528 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
1530 Changes to past timestamps
1532 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1534 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1535 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
1539 The reference localtime implementation now falls back on the
1540 current US daylight-saving transition rules rather than the
1541 1987-2006 rules. This fallback occurs only when (1) the TZ
1542 environment variable has a value like "AST4ADT" that asks
1543 for daylight saving time but does not specify the rules, (2) there
1544 is no file by that name, and (3) the TZDEFRULES file cannot be
1545 loaded. (Thanks to Tom Lane.)
1548 Release 2017a - 2017-02-28 00:05:36 -0800
1550 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1553 Changes to future timestamps
1555 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
1557 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1558 Its clocks diverge from America/Santiago starting 2017-05-13 at
1559 23:00, hiving off a new zone America/Punta_Arenas. Although the
1560 Chilean government says this change expires in May 2019, for now
1561 assume it's permanent. (Thanks to Juan Correa and Deborah
1562 Goldsmith.) This also affects Antarctica/Palmer.
1564 Changes to past timestamps
1566 Fix many entries for historical timestamps for Europe/Madrid
1567 before 1979, to agree with tables compiled by Pere Planesas of the
1568 National Astronomical Observatory of Spain. As a side effect,
1569 this changes some timestamps for Africa/Ceuta before 1929, which
1570 are probably guesswork anyway. (Thanks to Steve Allen and
1571 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1572 correcting the 1901 transition.)
1574 Ecuador observed DST from 1992-11-28 to 1993-02-05.
1575 (Thanks to Alois Treindl.)
1577 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1578 (Thanks to Stepan Golosunov.)
1580 Changes to past and future time zone abbreviations
1582 Switch to numeric time zone abbreviations for South America, as
1583 part of the ongoing project of removing invented abbreviations.
1584 This avoids the need to invent an abbreviation for the new Chilean
1585 new zone. Similarly, switch from invented to numeric time zone
1586 abbreviations for Afghanistan, American Samoa, the Azores,
1587 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1588 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1589 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1590 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1591 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1592 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1593 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1594 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1595 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1596 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1597 for half-hour daylight saving time in Belize before 1944 and in
1598 the Dominican Republic before 1975; and for Canary Islands before
1599 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1600 Indian Summer Time before 1942, for Indonesia before around 1964,
1601 for Kenya before 1960, for Liberia before 1973, for Madeira before
1602 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1603 Pakistan before 1971, for Western Sahara before 1977, and for
1604 Zaporozhye in 1880-1924.
1606 For Alaska time from 1900 through 1967, instead of "CAT" use the
1607 abbreviation "AST", the abbreviation commonly used at the time
1608 (Atlantic Standard Time had not been standardized yet). Use "AWT"
1609 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1611 Use "CST" and "CDT" instead of invented abbreviations for Macau
1612 before 1999 and Taiwan before 1938, and use "JST" instead of the
1613 invented abbreviation "JCST" for Japan and Korea before 1938.
1615 Change to database entry category
1617 Move the Pacific/Johnston link from 'australasia' to 'backward',
1618 since Johnston is now uninhabited.
1622 zic no longer mishandles some transitions in January 2038 when it
1623 attempts to work around Qt bug 53071. This fixes a bug affecting
1624 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
1625 now contains a workaround, useful when loading a file generated by
1626 a buggy zic. (Problem and localtime.c fix reported by Bradley
1629 zdump -i now outputs non-hour numeric time zone abbreviations
1630 without a colon, e.g., "+0530" rather than "+05:30". This agrees
1631 with zic %z and with common practice, and simplifies auditing of
1634 zdump is now buildable again with -DUSE_LTZ=0.
1635 (Problem reported by Joseph Myers.)
1637 zdump.c now always includes private.h, to avoid code duplication
1638 with private.h. (Problem reported by Kees Dekker.)
1640 localtime.c no longer mishandles early or late timestamps
1641 when TZ is set to a POSIX-style string that specifies DST.
1642 (Problem reported by Kees Dekker.)
1644 date and strftime now cause %z to generate "-0000" instead of
1645 "+0000" when the UT offset is zero and the time zone abbreviation
1648 Changes to documentation and commentary
1650 The 'Theory' file now better documents choice of historical time
1651 zone abbreviations. (Problems reported by Michael Deckers.)
1653 tz-link.htm now covers leap smearing, which is popular in clouds.
1656 Release 2016j - 2016-11-22 23:17:13 -0800
1658 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1660 Changes to future timestamps
1662 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
1663 This hives off a new zone Europe/Saratov from Europe/Volgograd.
1664 (Thanks to Yuri Konotopov and Stepan Golosunov.)
1666 Changes to past timestamps
1668 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
1669 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1670 1999, not fall 1994. (Thanks to Stepan Golosunov.)
1672 Changes to past time zone abbreviations
1674 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
1675 summer time before 1948. The old use of "EET" was a typo.
1679 zic no longer mishandles file systems that lack hard links, fixing
1680 bugs introduced in 2016g. (Problems reported by Tom Lane.)
1681 Also, when the destination already contains symbolic links, zic
1682 should now work better on systems where the 'link' system call
1683 does not follow symbolic links.
1685 Changes to documentation and commentary
1687 tz-link.htm now documents the relationship between release version
1688 numbers and development-repository commit tags. (Suggested by
1691 The 'Theory' file now documents UT.
1693 iso3166.tab now accents "Curaçao", and commentary now mentions
1694 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
1697 Release 2016i - 2016-11-01 23:19:52 -0700
1699 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
1700 reintroduces DST on 2016-11-06.
1702 Changes to future timestamps
1704 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
1705 2017-01-15 at 03:00. Assume future observances in Tonga will be
1706 from the first Sunday in November through the third Sunday in
1707 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
1708 time zone abbreviations for this zone.
1710 Changes to past and future timestamps
1712 Northern Cyprus is now +03 year round, causing a split in Cyprus
1713 time zones starting 2016-10-30 at 04:00. This creates a zone
1714 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
1716 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
1717 (Thanks to Steffen Thorsen.)
1719 Changes to past timestamps
1721 Several corrections were made for pre-1975 timestamps in Italy.
1722 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
1725 First, the 1893-11-01 00:00 transition in Italy used the new UT
1726 offset (+01), not the old (+00:49:56). (Thanks to Michael
1729 Second, rules for daylight saving in Italy were changed to agree
1730 with Italy's National Institute of Metrological Research (INRiM)
1731 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
1732 Inglis, and Michael Deckers):
1734 The 1916-06-03 transition was at 24:00, not 00:00.
1736 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
1739 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
1742 The 1944-09-17 transition was at 03:00, not 01:00. This
1743 particular change is taken from Italian law as INRiM's table,
1744 (which says 02:00) appears to have a typo here. Also, keep the
1745 1944-04-03 transition for Europe/Rome, as Rome was controlled by
1748 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
1753 The code should now be buildable on AmigaOS merely by setting the
1754 appropriate Makefile variables. (From a patch by Carsten Larsen.)
1757 Release 2016h - 2016-10-19 23:17:57 -0700
1759 Changes to future timestamps
1761 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
1762 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
1763 future fall transitions will be on the last Saturday of October
1764 at 01:00, which is consistent with predicted spring transitions
1765 on the last Saturday of March. (Thanks to Tim Parenti.)
1767 Changes to past timestamps
1769 In Turkey, transitions in 1986-1990 were at 01:00 standard time
1770 not at 02:00, and the spring 1994 transition was on March 20, not
1771 March 27. (Thanks to Kıvanç Yazan.)
1773 Changes to past and future time zone abbreviations
1775 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
1776 instead of alphabetic ones like "IST" and "LKT". Various
1777 English-language sources use "IST", "LKT" and "SLST", with no
1778 working consensus. (Usage of "SLST" mentioned by Sadika
1783 zic no longer mishandles relativizing file names when creating
1784 symbolic links like /etc/localtime, when these symbolic links
1785 are outside the usual directory hierarchy. This fixes a bug
1786 introduced in 2016g. (Problem reported by Andreas Stieger.)
1788 Changes to build procedure
1790 New rules 'traditional_tarballs' and 'traditional_signatures' for
1791 building just the traditional-format distribution. (Requested by
1794 The file 'version' is now put into the tzdata tarball too.
1795 (Requested by Howard Hinnant.)
1797 Changes to documentation and commentary
1799 The 'Theory' file now has a section on interface stability.
1800 (Requested by Paul Koning.) It also mentions features like
1801 tm_zone and localtime_rz that have long been supported by the
1804 tz-link.htm has improved coverage of time zone boundaries suitable
1805 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
1808 The US commentary now mentions Allen and the "day of two noons".
1810 The Fiji commentary mentions the government's 2016-10-03 press
1811 release. (Thanks to Raymond Kumar.)
1814 Release 2016g - 2016-09-13 08:56:38 -0700
1816 Changes to future timestamps
1818 Turkey switched from EET/EEST (+02/+03) to permanent +03,
1819 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
1820 than an invented abbreviation for the new time.
1822 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
1823 (Thanks to Tim Parenti.)
1825 Changes to past timestamps
1827 For America/Los_Angeles, spring-forward transition times have been
1828 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
1831 For zones using Soviet time on 1919-07-01, transitions to UT-based
1832 time were at 00:00 UT, not at 02:00 local time. The affected
1833 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
1834 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
1836 Changes to past and future time zone abbreviations
1838 The Factory zone now uses the time zone abbreviation -00 instead
1839 of a long English-language string, as -00 is now the normal way to
1840 represent an undefined time zone.
1842 Several zones in Antarctica and the former Soviet Union, along
1843 with zones intended for ships at sea that cannot use POSIX TZ
1844 strings, now use numeric time zone abbreviations instead of
1845 invented or obsolete alphanumeric abbreviations. The affected
1846 zones are Antarctica/Casey, Antarctica/Davis,
1847 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
1848 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
1849 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
1850 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
1851 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
1852 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
1853 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
1854 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
1855 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
1856 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
1857 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
1858 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
1859 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
1860 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
1861 was replaced by +05, whereas MSK and MSD were kept as they are not
1862 our invention and are widely used.
1864 Changes to zone names
1866 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
1867 (Thanks to David Massoud.)
1871 zic no longer generates binary files containing POSIX TZ-like
1872 strings that disagree with the local time type after the last
1873 explicit transition in the data. This fixes a bug with
1874 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
1875 on the reference platform. (Thanks to Alexander Belopolsky for
1876 reporting the bug and suggesting a way forward.)
1878 If the installed localtime and/or posixrules files are symbolic
1879 links, zic now keeps them symbolic links when updating them, for
1880 compatibility with platforms like OpenSUSE where other programs
1881 configure these files as symlinks.
1883 zic now avoids hard linking to symbolic links, avoids some
1884 unnecessary mkdir and stat system calls, and uses shorter file
1887 zdump has a new -i option to generate transitions in a
1888 more-compact but still human-readable format. This option is
1889 experimental, and the output format may change in future versions.
1890 (Thanks to Jon Skeet for suggesting that an option was needed,
1891 and thanks to Tim Parenti and Chris Rovick for further comments.)
1893 Changes to build procedure
1895 An experimental distribution format is available, in addition
1896 to the traditional format which will continue to be distributed.
1897 The new format is a tarball tzdb-VERSION.tar.lz with signature
1898 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
1899 tzdb-VERSION containing the code and data of the traditional
1900 two-tarball format, along with extra data that may be useful.
1901 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
1902 for comments about the experimental format.)
1904 The release version number is now more accurate in the usual case
1905 where releases are built from a Git repository. For example, if
1906 23 commits and some working-file changes have been made since
1907 release 2016g, the version number is now something like
1908 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
1909 Tagged releases use the same version number format as before,
1910 e.g., '2016g'. To support the more-accurate version number, its
1911 specification has moved from a line in the Makefile to a new
1912 source file 'version'.
1914 The experimental distribution contains a file to2050.tzs that
1915 contains what should be the output of 'zdump -i -c 2050' on
1916 primary zones. If this file is available, 'make check' now checks
1917 that zdump generates this output.
1919 'make check_web' now works on Fedora-like distributions.
1921 Changes to documentation and commentary
1923 tzfile.5 now documents the new restriction on POSIX TZ-like
1924 strings that is now implemented by zic.
1926 Comments now cite URLs for some 1917-1921 Russian DST decrees.
1927 (Thanks to Alexander Belopolsky.)
1929 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
1930 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
1931 description of Java 8 has been brought up to date (thanks to
1932 Stephen Colebourne). Its description of local time on Mars has
1933 been updated to match current practice, and URLs have been updated
1934 and some obsolete ones removed.
1937 Release 2016f - 2016-07-05 16:26:51 +0200
1939 Changes affecting future timestamps
1941 The Egyptian government changed its mind on short notice, and
1942 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
1943 (Thanks to Mina Samuel.)
1945 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
1946 (Thanks to Stepan Golosunov.)
1948 Changes to past and future timestamps
1950 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
1951 abbreviations instead of invented ones.
1953 Changes affecting past timestamps
1955 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
1956 (Thanks to Stepan Golosunov.)
1959 Release 2016e - 2016-06-14 08:46:16 -0700
1961 Changes affecting future timestamps
1963 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
1964 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
1965 For future years, guess April's last Thursday to October's last
1966 Thursday except for Ramadan.
1968 Changes affecting past timestamps
1970 Locations while uninhabited now use '-00', not 'zzz', as a
1971 placeholder time zone abbreviation. This is inspired by Internet
1972 RFC 3339 and is more consistent with numeric time zone
1973 abbreviations already used elsewhere. The change affects several
1974 arctic and antarctic locations, e.g., America/Cambridge_Bay before
1975 1920 and Antarctica/Troll before 2005.
1977 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
1978 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
1982 zic now outputs a dummy transition at time 2**31 - 1 in zones
1983 whose POSIX-style TZ strings contain a '<'. This mostly works
1984 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
1985 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
1987 Changes affecting documentation and commentary
1989 tz-link.htm says why governments should give plenty of notice for
1990 time zone or DST changes, and refers to Matt Johnson's blog post.
1992 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
1995 Release 2016d - 2016-04-17 22:50:29 -0700
1997 Changes affecting future timestamps
1999 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2000 (Thanks to Alexander Krivenyshev for the heads-up.)
2002 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2003 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2005 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2006 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2007 at 02:00. (Thanks to Stepan Golosunov.)
2009 Changes affecting past timestamps
2011 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2012 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2013 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2014 the same change. (Thanks to Stepan Golosunov.)
2016 Russia and nearby locations had daylight-saving transitions on
2017 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2018 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2021 Many corrections to historical time in Kazakhstan from 1991
2022 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2023 invented time zone abbreviations with numeric abbreviations.
2025 Changes to commentary
2027 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2030 Release 2016c - 2016-03-23 00:51:27 -0700
2032 Changes affecting future timestamps
2034 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2036 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2037 Correa for the heads-up, and to Tim Parenti for corrections.)
2038 Guess that future transitions are August's and May's second
2039 Saturdays at 24:00 mainland time. Also, call the period from
2040 2014-09-07 through 2016-05-14 daylight saving time instead of
2041 standard time, as that seems more appropriate now.
2043 Changes affecting past timestamps
2045 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2046 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2047 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2048 (Thanks to Stepan Golosunov.)
2050 Changes to commentary
2052 Several updates and URLs for historical and proposed Russian changes.
2053 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2056 Release 2016b - 2016-03-12 17:30:14 -0800
2060 Starting with release 2016b, some data entries cause zic implementations
2061 derived from tz releases 2005j through 2015e to issue warnings like
2062 "time zone abbreviation differs from POSIX standard (+03)".
2063 These warnings should not otherwise affect zic's output and can safely be
2064 ignored on today's platforms, as the warnings refer to a restriction in
2065 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2066 warnings is to upgrade to zic derived from tz releases 2015f and later.
2068 Changes affecting future timestamps
2070 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2071 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2072 2016-03-27 at 02:00 local time. They need distinct zones since their
2073 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2074 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2075 and local time. The Astrakhan change is already official; the others have
2076 passed the first reading in the State Duma and are extremely likely.
2077 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2078 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2079 and Stepan Golosunov for followup.)
2081 As a trial of a new system that needs less information to be made up,
2082 the new zones use numeric time zone abbreviations like "+04"
2083 instead of invented abbreviations like "ASTT".
2085 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2088 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2089 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2090 Saturday at 01:00, not March's last Friday at 24:00.
2092 Changes affecting past timestamps
2094 Europe/Chisinau observed DST during 1990, and switched from +04 to
2095 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2096 (Thanks to Stepan Golosunov.)
2098 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2099 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2103 tzselect's diagnostics and checking, and checktab.awk's checking,
2104 have been improved. (Thanks to J William Piggott.)
2106 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2108 tzselect now tests Julian-date TZ settings more accurately.
2109 (Thanks to J William Piggott.)
2111 Changes to commentary
2113 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2115 tzselect again limits its menu comments so that menus fit on a
2116 24×80 alphanumeric display.
2118 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2120 In the Theory file, the description of possible time zone abbreviations in
2121 tzdata has been cleaned up, as the old description was unclear and
2122 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2125 Release 2016a - 2016-01-26 23:28:02 -0800
2127 Changes affecting future timestamps
2129 America/Cayman will not observe daylight saving this year after all.
2130 Revert our guess that it would. (Thanks to Matt Johnson.)
2132 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2133 (Thanks to Alexander Krivenyshev.)
2135 Asia/Tehran now has DST predictions for the year 2038 and later,
2136 to be March 21 00:00 to September 21 00:00. This is likely better
2137 than predicting no DST, albeit off by a day every now and then.
2139 Changes affecting past and future timestamps
2141 America/Metlakatla switched from PST all year to AKST/AKDT on
2142 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2144 America/Santa_Isabel has been removed, and replaced with a
2145 backward compatibility link to America/Tijuana. Its contents were
2146 apparently based on a misreading of Mexican legislation.
2148 Changes affecting past timestamps
2150 Asia/Karachi's two transition times in 2002 were off by a minute.
2151 (Thanks to Matt Johnson.)
2153 Changes affecting build procedure
2155 An installer can now combine leap seconds with use of the backzone file,
2156 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2157 The old 'make posix_packrat' rule is now marked as obsolescent.
2158 (Thanks to Ian Abbott for an initial implementation.)
2160 Changes affecting documentation and commentary
2162 A new file LICENSE makes it easier to see that the code and data
2163 are mostly public-domain. (Thanks to James Knight.) The three
2164 non-public-domain files now use the current (3-clause) BSD license
2165 instead of older versions of that license.
2167 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2168 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2169 on editing tz source files (with a mention of Sublime zoneinfo,
2170 thanks to Gilmore Davidson).
2172 The Theory and asia files now mention the 2015 book "The Global
2173 Transformation of Time, 1870-1950", and cite a couple of reviews.
2175 The America/Chicago entry now documents the informal use of US
2176 central time in Fort Pierre, South Dakota. (Thanks to Rick
2177 McDermid, Matt Johnson, and Steve Jones.)
2180 Release 2015g - 2015-10-01 00:39:51 -0700
2182 Changes affecting future timestamps
2184 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2187 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2188 (Thanks to Alexander Krivenyshev.)
2190 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2191 (Thanks to Ken Rylander.)
2193 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2194 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2195 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2197 Changes affecting past timestamps
2199 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2201 Changes affecting code
2203 localtime no longer mishandles America/Anchorage after 2037.
2204 (Thanks to Bradley White for reporting the bug.)
2206 On hosts with signed 32-bit time_t, localtime no longer mishandles
2207 Pacific/Fiji after 2038-01-16 14:00 UTC.
2209 The localtime module allows the variables 'timezone', 'daylight',
2210 and 'altzone' to be in common storage shared with other modules,
2211 and declares them in case the system <time.h> does not.
2212 (Problems reported by Kees Dekker.)
2214 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2215 This simplifies the code and is consistent with zdump.c.
2216 (Problem reported by Christos Zoulas.)
2218 Changes affecting documentation
2220 The tzfile man page now documents that transition times denote the
2221 starts (not the ends) of the corresponding time periods.
2222 (Ambiguity reported by Bill Seymour.)
2225 Release 2015f - 2015-08-10 18:06:56 -0700
2227 Changes affecting future timestamps
2229 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2230 The abbreviation remains "KST". (Thanks to Robert Elz.)
2232 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2235 Changes affecting past and future timestamps
2237 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2238 (Thanks to Roman Tudos.)
2240 Changes affecting data format and code
2242 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2243 field of a Rule line should now be '-'; the old values 'even',
2244 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2245 Although the implementation has not changed, these features do not
2246 work in the default installation, they are not used in the data,
2247 and they are now considered obsolescent.
2249 zic now checks that two rules don't take effect at the same time.
2250 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2251 simultaneity are now documented.
2253 The two characters '%z' in a zone format now stand for the UT
2254 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2255 five hours and thirty minutes ahead. This better supports time
2256 zone abbreviations conforming to POSIX.1-2001 and later.
2258 Changes affecting installed data files
2260 Comments for America/Halifax and America/Glace_Bay have been improved.
2261 (Thanks to Brian Inglis.)
2263 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2264 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2265 installed data files for Europe/Simferopol and Europe/Tallinn.
2266 It does not affect timestamps. (Thanks to Howard Hinnant.)
2268 Changes affecting code
2270 zdump and zic no longer warn about valid time zone abbreviations
2273 Some Visual Studio 2013 warnings have been suppressed.
2274 (Thanks to Kees Dekker.)
2276 'date' no longer sets the time of day and its -a, -d, -n and -t
2277 options have been removed. Long obsolescent, the implementation
2278 of these features had porting problems. Builders no longer need
2279 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2280 (Thanks to Kees Dekker for pointing out the problem.)
2282 Changes affecting documentation
2284 The Theory file mentions naming issues earlier, as these seem to be
2285 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2287 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2289 Mention that Herbert Samuel introduced the term "Summer Time".
2292 Release 2015e - 2015-06-13 10:56:02 -0700
2294 Changes affecting future timestamps
2296 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2297 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2299 Assume Cayman Islands will observe DST starting next year, using US rules.
2300 Although it isn't guaranteed, it is the most likely.
2302 Changes affecting data format
2304 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2305 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2307 Changes affecting code
2309 When displaying data, tzselect converts it to the current locale's
2310 encoding if the iconv command works. (Problem reported by random832.)
2312 tzselect no longer mishandles Dominica, fixing a bug introduced
2313 in Release 2014f. (Problem reported by Owen Leibman.)
2315 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2316 This fixes a bug introduced in Release 2014f.
2317 (Problem reported by Leonardo Chiquitto.)
2320 Release 2015d - 2015-04-24 08:09:46 -0700
2322 Changes affecting future timestamps
2324 Egypt will not observe DST in 2015 and will consider canceling it
2325 permanently. For now, assume no DST indefinitely.
2326 (Thanks to Ahmed Nazmy and Tim Parenti.)
2328 Changes affecting past timestamps
2330 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2331 1966-07-01. Also, Yukon's time zone history is documented better.
2332 (Thanks to Brian Inglis and Dennis Ferguson.)
2334 Change affecting past and future time zone abbreviations
2336 The abbreviations for Hawaii-Aleutian standard and daylight times
2337 have been changed from HAST/HADT to HST/HDT, as per US Government
2338 Printing Office style. This affects only America/Adak since 1983,
2339 as America/Honolulu was already using the new style.
2341 Changes affecting code
2343 zic has some minor performance improvements.
2346 Release 2015c - 2015-04-11 08:55:55 -0700
2348 Changes affecting future timestamps
2350 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2351 not 00:00 on April's last Friday. 2015's transition will therefore be on
2352 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2353 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2355 Changes affecting past timestamps
2357 The following changes affect some pre-1991 Chile-related timestamps
2358 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2360 The 1910 transition was January 10, not January 1.
2362 The 1918 transition was September 10, not September 1.
2364 The UT -04 time observed from 1932 to 1942 is now considered to
2365 be standard time, not year-round DST.
2367 Santiago observed DST (UT -03) from 1946-07-15 through
2368 1946-08-31, then reverted to standard time, then switched to -05
2371 Assume transitions before 1968 were at 00:00, since we have no data
2374 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2375 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2377 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2378 and omit all transitions on Pacific/Easter from 1942 through 1946
2379 since we have no data suggesting that they existed.
2381 One more zone has been turned into a link, as it differed
2382 from an existing zone only for older timestamps. As usual,
2383 this change affects UT offsets in pre-1970 timestamps only.
2384 The zone's old contents have been moved to the 'backzone' file.
2385 The affected zone is America/Montreal.
2387 Changes affecting commentary
2389 Mention the TZUpdater tool.
2391 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2394 Release 2015b - 2015-03-19 23:28:11 -0700
2396 Changes affecting future timestamps
2398 Mongolia will start observing DST again this year, from the last
2399 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2400 (Thanks to Ganbold Tsagaankhuu.)
2402 Palestine will start DST on March 28, not March 27. Also,
2403 correct the fall 2014 transition from September 26 to October 24.
2404 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2406 Changes affecting past timestamps
2408 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2409 regression. (Thanks to Stuart Bishop for reporting the problem.)
2411 Some more zones have been turned into links, when they differed
2412 from existing zones only for older timestamps. As usual,
2413 these changes affect UT offsets in pre-1970 timestamps only.
2414 Their old contents have been moved to the 'backzone' file.
2415 The affected zones are: America/Antigua, America/Cayman,
2416 Pacific/Midway, and Pacific/Saipan.
2418 Changes affecting time zone abbreviations
2420 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2423 Changes affecting code
2425 Fix integer overflow bug in reference 'mktime' implementation.
2426 (Problem reported by Jörg Richter.)
2428 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2429 to be used in the same executable as standard-library time_t functions.
2430 (Problems reported by Bradley White.)
2432 Changes affecting commentary
2434 Cite the recent Mexican decree changing Quintana Roo's time zone.
2435 (Thanks to Carlos Raúl Perasso.)
2437 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2439 Update info about Mars time.
2442 Release 2015a - 2015-01-29 22:35:20 -0800
2444 Changes affecting future timestamps
2446 The Mexican state of Quintana Roo, represented by America/Cancun,
2447 will shift from Central Time with DST to Eastern Time without DST
2448 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2450 Chile will not change clocks in April or thereafter; its new standard time
2451 will be its old daylight saving time. This affects America/Santiago,
2452 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2454 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2455 (Thanks to Tim Parenti.)
2457 Changes affecting past timestamps
2459 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2460 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2461 Shanks about time in Iceland between 1837 and 1908.
2463 Some more zones have been turned into links, when they differed
2464 from existing zones only for older timestamps. As usual,
2465 these changes affect UT offsets in pre-1970 timestamps only.
2466 Their old contents have been moved to the 'backzone' file.
2467 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2470 Changes affecting code
2472 tzalloc now scrubs time zone abbreviations compatibly with the way
2473 that tzset always has, by replacing invalid bytes with '_' and by
2474 shortening too-long abbreviations.
2476 tzselect ports to POSIX awk implementations, no longer mishandles
2477 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2478 settings to the user. (Thanks to Stefan Kuhn.)
2480 Changes affecting build procedure
2482 'make check' now checks for links to links in the data.
2483 One such link (for Africa/Asmera) has been fixed.
2484 (Thanks to Stephen Colebourne for pointing out the problem.)
2486 Changes affecting commentary
2488 The leapseconds file commentary now mentions the expiration date.
2489 (Problem reported by Martin Burnicki.)
2491 Update Mexican Library of Congress URL.
2494 Release 2014j - 2014-11-10 17:37:11 -0800
2496 Changes affecting current and future timestamps
2498 Turks & Caicos' switch from US eastern time to UT -04 year-round
2499 did not occur on 2014-11-02 at 02:00. It's currently scheduled
2500 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
2502 Changes affecting past timestamps
2504 Many pre-1989 timestamps have been corrected for Asia/Seoul and
2505 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2506 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
2507 longer guess that Pyongyang mimicked Seoul time after World War II,
2508 as this is politically implausible.
2510 Some more zones have been turned into links, when they differed
2511 from existing zones only for older timestamps. As usual,
2512 these changes affect UT offsets in pre-1970 timestamps only.
2513 Their old contents have been moved to the 'backzone' file.
2514 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2515 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2516 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2519 Changes affecting commentary
2521 The commentary is less enthusiastic about Shanks as a source,
2522 and is more careful to distinguish UT from UTC.
2525 Release 2014i - 2014-10-21 22:04:57 -0700
2527 Changes affecting future timestamps
2529 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2530 (Thanks to Ken Rylander for the heads-up.) Guess that future
2531 years will use a similar pattern.
2533 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2534 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2535 (Thanks to Kiley Walbom for the heads-up.)
2537 Changes affecting time zone abbreviations
2539 Since Belarus is not changing its clocks even though Moscow is,
2540 the time zone abbreviation in Europe/Minsk is changing from FET
2541 to its more-traditional value MSK on 2014-10-26 at 01:00.
2542 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2544 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2545 Indochina, to distinguish it better from ICT (+07).
2547 Changes affecting past timestamps
2549 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2550 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2551 authoritative book). Asia/Ho_Chi_Minh has been added to
2552 zone1970.tab, to give tzselect users in Vietnam two choices,
2553 since north and south Vietnam disagreed after our 1970 cutoff.
2555 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2556 they differed from existing zones only for older timestamps. As
2557 usual, these changes affect pre-1970 timestamps only. Their old
2558 contents have been moved to the 'backzone' file.
2560 Changes affecting code
2562 The time-related library functions now set errno on failure, and
2563 some crashes in the new tzalloc-related library functions have
2564 been fixed. (Thanks to Christos Zoulas for reporting most of
2565 these problems and for suggesting fixes.)
2567 If USG_COMPAT is defined and the requested timestamp is standard time,
2568 the tz library's localtime and mktime functions now set the extern
2569 variable timezone to a value appropriate for that timestamp; and
2570 similarly for ALTZONE, daylight saving time, and the altzone variable.
2571 This change is a companion to the tzname change in 2014h, and is
2572 designed to make timezone and altzone more compatible with tzname.
2574 The tz library's functions now set errno to EOVERFLOW if they fail
2575 because the result cannot be represented. ctime and ctime_r now
2576 return NULL and set errno when a timestamp is out of range, rather
2577 than having undefined behavior.
2579 Some bugs associated with the new 2014g functions have been fixed.
2580 This includes a bug that largely incapacitated the new functions
2581 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
2582 It also includes some uses of uninitialized variables after tzalloc.
2583 The new code uses the standard type 'ssize_t', which the Makefile
2584 now gives porting advice about.
2586 Changes affecting commentary
2588 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2591 Release 2014h - 2014-09-25 18:59:03 -0700
2593 Changes affecting past timestamps
2595 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2597 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2598 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
2600 Some more zones have been turned into links, when they differed
2601 from existing zones only for older timestamps. As usual,
2602 these changes affect UT offsets in pre-1970 timestamps only.
2603 Their old contents have been moved to the 'backzone' file.
2604 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2605 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2606 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2608 Changes affecting code
2610 zdump -V and -v now output gmtoff= values on all platforms,
2611 not merely on platforms defining TM_GMTOFF.
2613 The tz library's localtime and mktime functions now set tzname to a value
2614 appropriate for the requested timestamp, and zdump now uses this
2615 on platforms not defining TM_ZONE, fixing a 2014g regression.
2616 (Thanks to Tim Parenti for reporting the problem.)
2618 The tz library no longer sets tzname if localtime or mktime fails.
2620 zdump -c no longer mishandles transitions near year boundaries.
2621 (Thanks to Tim Parenti for reporting the problem.)
2623 An access to uninitialized data has been fixed.
2624 (Thanks to Jörg Richter for reporting the problem.)
2626 When THREAD_SAFE is defined, the code ports to the C11 memory model.
2627 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2628 and two threads race to initialize data used by gmtime-like functions.
2629 (Thanks to Andy Heninger for reporting the problems.)
2631 Changes affecting build procedure
2633 'make check' now checks better for properly-sorted data.
2635 Changes affecting documentation and commentary
2637 zdump's gmtoff=N output is now documented, and its isdst=D output
2638 is now documented to possibly output D values other than 0 or 1.
2640 zdump -c's treatment of years is now documented to use the
2641 Gregorian calendar and Universal Time without leap seconds,
2642 and its behavior at cutoff boundaries is now documented better.
2643 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2645 Programs are now documented to use the proleptic Gregorian calendar.
2646 (Thanks to Alan Barrett for the suggestion.)
2648 Fractional-second GMT offsets have been documented for civil time
2649 in 19th-century Chennai, Jakarta, and New York.
2652 Release 2014g - 2014-08-28 12:31:23 -0700
2654 Changes affecting future timestamps
2656 Turks & Caicos is switching from US eastern time to UT -04
2657 year-round, modeled as a switch on 2014-11-02 at 02:00.
2658 [As noted in 2014j, this switch was later delayed.]
2660 Changes affecting past timestamps
2662 Time in Russia or the USSR before 1926 or so has been corrected by
2663 a few seconds in the following zones: Asia/Irkutsk,
2664 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
2665 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
2666 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
2667 Vladimir Karpinsky.)
2669 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
2670 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
2671 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
2672 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
2673 (Thanks to Stephen Colebourne for pointing to the decree.)
2675 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
2677 A new file 'backzone' contains data which may appeal to
2678 connoisseurs of old timestamps, although it is out of scope for
2679 the tz database, is often poorly sourced, and contains some data
2680 that is known to be incorrect. The new file is not recommended
2681 for ordinary use and its entries are not installed by default.
2682 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
2683 Isle of Man entries.)
2685 Some more zones have been turned into links, when they differed
2686 from existing zones only for older timestamps. As usual,
2687 these changes affect UT offsets in pre-1970 timestamps only.
2688 Their old contents have been moved to the 'backzone' file.
2689 The affected zones are: Africa/Bangui, Africa/Brazzaville,
2690 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
2691 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
2693 Changes affecting code
2695 Unless NETBSD_INSPIRED is defined to 0, the tz library now
2696 supplies functions for creating and using objects that represent
2697 timezones. The new functions are tzalloc, tzfree, localtime_rz,
2698 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
2699 time2posix_z. They are intended for performance: for example,
2700 localtime_rz (unlike localtime_r) is trivially thread-safe without
2701 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
2702 functions, and to Alan Barrett and Jonathan Lennox for helping to
2705 zdump now builds with the tz library unless USE_LTZ is defined to 0,
2706 This lets zdump use tz features even if the system library lacks them.
2707 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
2708 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
2710 zdump now uses localtime_rz if available, as it's significantly faster,
2711 and it can help zdump better diagnose invalid timezone names.
2712 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
2713 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
2714 not available, zdump now uses localtime_r and tzset if available,
2715 as this is a bit cleaner and faster than plain localtime. Compile
2716 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
2717 lacks these two functions.
2719 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
2720 Although not needed for tz's own applications, which are single-threaded,
2721 this supports POSIX better if the tz library is used in multithreaded apps.
2723 Some crashes have been fixed when zdump or the tz library is given
2724 invalid or outlandish input.
2726 The tz library no longer mishandles leap seconds on platforms with
2727 unsigned time_t in timezones that lack ordinary transitions after 1970.
2729 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
2730 already defined, to make it easier to configure on common platforms.
2731 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
2733 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
2734 assumes that reading uninitialized memory yields garbage values
2735 but does not cause other problems such as traps.
2737 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
2738 more likely to guess right for ambiguous timestamps near
2739 transitions where tm_isdst does not change.
2741 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
2742 strftime_l for compatibility with recent versions of POSIX.
2743 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
2744 to 1 on recent POSIX versions, and to 0 otherwise.
2746 tzselect -c now uses a hybrid distance measure that works better
2747 in Africa. (Thanks to Alan Barrett for noting the problem.)
2749 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
2750 or when time_tz is defined.
2752 When HAVE_UTMPX_H is set the 'date' command now builds on systems
2753 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
2754 the date it updates the wtmpx file if _PATH_WTMPX is defined.
2755 This affects GNU/Linux and similar systems.
2757 For easier maintenance later, some C code has been simplified,
2758 some lint has been removed, and the code has been tweaked so that
2759 plain 'make' is more likely to work.
2761 The C type 'bool' is now used for boolean values, instead of 'int'.
2763 The long-obsolete LOCALE_HOME code has been removed.
2765 The long-obsolete 'gtime' function has been removed.
2767 Changes affecting build procedure
2769 'zdump' no longer links in ialloc.o, as it's not needed.
2771 'make check_time_t_alternatives' no longer assumes GNU diff.
2773 Changes affecting distribution tarballs
2775 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
2776 the tzdata tarball instead of the tzcode tarball, since they help
2777 maintain the data. The NEWS and Theory files are now also
2778 distributed in the tzdata tarball, as they're relevant for data.
2779 (Thanks to Alan Barrett for pointing this out.) Also, the
2780 leapseconds.awk file is no longer distributed in the tzcode
2781 tarball, since it belongs in the tzdata tarball (where 2014f
2782 inadvertently also distributed it).
2784 Changes affecting documentation and commentary
2786 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
2787 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
2790 The man pages have been updated to use function prototypes,
2791 to document thread-safe variants like localtime_r, and to document
2792 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
2795 The fields in Link lines have been renamed to be more descriptive
2796 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
2797 and LINK-TO has become LINK-NAME.
2799 tz-link.htm mentions the IETF's tzdist working group; Windows
2800 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
2802 Some broken URLs have been fixed in the commentary. (Thanks to
2805 Commentary about Philippines DST has been updated, and commentary
2806 on pre-1970 time in India has been added.
2809 Release 2014f - 2014-08-05 17:42:36 -0700
2811 Changes affecting future timestamps
2813 Russia will subtract an hour from most of its time zones on 2014-10-26
2814 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
2815 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
2816 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
2817 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
2818 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
2819 (Europe/Samara) are not changing their clocks. The changed zones are
2820 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
2821 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
2822 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
2823 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
2824 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
2825 but not its UTC offset. Two zones are added: Asia/Chita (split
2826 from Asia/Yakutsk, and also with two hours subtracted) and
2827 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
2828 subtracted). (Thanks to Tim Parenti for much of the above.)
2830 Changes affecting time zone abbreviations
2832 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
2833 and similarly for the other Australian zones. That is, for eastern
2834 standard and daylight saving time the abbreviations are AEST and AEDT
2835 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
2836 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
2837 This change does not affect UT offsets, only time zone abbreviations.
2838 (Thanks to Rich Tibbett and many others.)
2840 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
2841 effective 2014-10-26 at 02:00 local time.
2843 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
2844 has been changed from URUT to XJT. (Thanks to Luther Ma.)
2846 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
2847 Similarly, prefer EET/EEST for eastern European time in Russia.
2849 Change time zone abbreviations in (western) Samoa to use "ST" and
2850 "DT" suffixes, as this is more likely to match common practice.
2851 Prefix "W" to (western) Samoa time when its standard-time offset
2852 disagrees with that of American Samoa.
2854 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
2856 Time zone abbreviations have been updated for Japan's two time
2857 zones used 1896-1937. JWST now stands for Western Standard
2858 Time, and JCST for Central Standard Time (formerly this was CJT).
2859 These abbreviations are now used for time in Korea, Taiwan,
2860 and Sakhalin while controlled by Japan.
2862 Changes affecting past timestamps
2864 China's five zones have been simplified to two, since the post-1970
2865 differences in the other three seem to have been imaginary. The
2866 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
2867 removed; backwards-compatibility links still work, albeit with
2868 different behaviors for timestamps before May 1980. Asia/Urumqi's
2869 1980 transition to UT +08 has been removed, so that it is now at
2870 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
2871 Treindl sent helpful translations of two papers by Guo Qingsheng.)
2873 Some zones have been turned into links, when they differed from existing
2874 zones only for older UT offsets where data entries were likely invented.
2875 These changes affect UT offsets in pre-1970 timestamps only. This is
2876 similar to the change in release 2013e, except this time for western
2877 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
2878 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
2879 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
2880 Atlantic/St_Helena. This also affects the backwards-compatibility
2881 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
2882 Tim Parenti, and David Patte for reporting problems in earlier
2883 versions of this change.)
2885 Asia/Shanghai's pre-standard-time UT offset has been changed from
2886 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
2887 transition to standard time has been changed from 1928 to 1901.
2889 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
2890 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
2891 In 1946 it observed DST from 05-15 through 09-30; in 1947
2892 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
2893 (Thanks to Yu-Cheng Chuang.)
2895 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
2897 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
2898 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
2900 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
2901 period from 1911 to 1950.
2903 Pacific/Chatham has been changed to New Zealand standard time plus
2904 45 minutes for the period before 1957, reflecting a 1956 remark in
2905 the New Zealand parliament.
2907 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
2908 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
2909 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
2910 not 04-06 at 02:00; and there was no DST in 1920.
2912 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
2914 Time in Russia before 1927 or so has been corrected by a few seconds in
2915 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
2916 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
2917 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
2918 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
2920 Changes affecting data format
2922 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
2923 The new file's extended format allows multiple country codes per zone.
2924 The older file is still installed but is deprecated; its format is
2925 not changing and it will still be distributed for a while, but new
2926 applications should use the new file.
2928 The new file format simplifies maintenance of obscure locations.
2929 To test this, it adds coverage for the Crozet Islands and the
2930 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
2932 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
2933 It is still ASCII now, but commentary about the switch has been added.
2934 The new file 'zone1970.tab' already uses UTF-8.
2936 Changes affecting code
2938 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
2939 is defined. (Thanks to Elliott Hughes for reporting the problem.)
2941 'zic' no longer mishandles input when ignoring case in locales that
2942 are not compatible with English, e.g., unibyte Turkish locales when
2943 compiled with HAVE_GETTEXT.
2945 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
2946 they no longer use ASCII '-' as if it were a dash.
2948 'zic' now rejects output file names that contain '.' or '..' components.
2949 (Thanks to Tim Parenti for reporting the problem.)
2951 'zic -v' now warns about output file names that do not follow
2952 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
2953 David Olson for starting the ball rolling on this.)
2955 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
2957 Changes affecting build procedure
2959 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
2960 (Thanks to John Cochran.)
2962 Changes affecting documentation and commentary
2964 The 'Theory' file documents legacy names, the longstanding
2965 exceptions to the POSIX-inspired file name rules.
2967 The 'zic' documentation clarifies the role of time types when
2968 interpreting dates. (Thanks to Arthur David Olson.)
2970 Documentation and commentary now prefer UTF-8 to US-ASCII,
2971 allowing the use of proper accents in foreign words and names.
2972 Code and data have not changed because of this. (Thanks to
2973 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
2976 Non-HTML documentation and commentary now use plain-text URLs instead of
2977 HTML insertions, and are more consistent about bracketing URLs when they
2978 are not already surrounded by white space. (Thanks to suggestions by
2981 There is new commentary about Xujiahui Observatory, the five time-zone
2982 project in China from 1918 to 1949, timekeeping in Japanese-occupied
2983 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
2984 warlord Jin Shuren in the data.
2986 Commentary about the coverage of each Russian zone has been standardized.
2987 (Thanks to Tim Parenti.)
2989 There is new commentary about contemporary timekeeping in Ethiopia.
2991 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
2993 There is new commentary about time in Poland in 1919.
2995 Proper credit has been given to DST inventor George Vernon Hudson.
2997 Commentary about time in Metlakatla, AK and Resolute, NU has been
2998 improved, with a new source for the former.
3000 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3003 Commentary about permanent Antarctic bases has been updated.
3005 Several typos have been corrected. (Thanks to Tim Parenti for
3006 contributing some of these fixes.)
3008 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3009 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3010 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3011 (Thanks to a heads-up from Dirkjan Ochtman.)
3013 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3014 have been removed. These obsolescent US Naval Observatory entries were no
3015 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3018 Release 2014e - 2014-06-12 21:53:52 -0700
3020 Changes affecting near-future timestamps
3022 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3023 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3024 switch to standard time at 24:00 the last Thursday before Ramadan, and
3025 back to DST at 00:00 the first Friday after Ramadan.
3027 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3028 to Milamber Space Network.) Guess that from 2015 on Morocco will
3029 temporarily switch to standard time at 03:00 the last Saturday before
3030 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3032 Changes affecting past timestamps
3034 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3035 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3036 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3037 in 1991. (Thanks to Hank W. for reporting the problems.)
3039 Changes affecting commentary
3041 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3042 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3043 removes stale pointers to World Time Explorer and WORLDTIME.
3046 Release 2014d - 2014-05-27 21:34:40 -0700
3048 Changes affecting code
3050 zic no longer generates files containing timestamps before the Big Bang.
3051 This works around GNOME glib bug 878
3052 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3053 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3054 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3056 Changes affecting documentation
3058 tz-link.htm now mentions GNOME.
3061 Release 2014c - 2014-05-13 07:44:13 -0700
3063 Changes affecting near-future timestamps
3065 Egypt observes DST starting 2014-05-15 at 24:00.
3066 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3067 Details have not been announced, except that DST will not be observed
3068 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3069 Morocco, and that Egypt's future spring and fall transitions will be the
3070 same as 2010 when it last observed DST, namely April's last Friday at
3071 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3072 that Ramadan transitions will be at 00:00 standard time.
3074 Changes affecting code
3076 zic now generates transitions for minimum time values, eliminating guesswork
3077 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3079 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3081 Changes affecting commentary and documentation
3083 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3086 Release 2014b - 2014-03-24 21:28:50 -0700
3088 Changes affecting near-future timestamps
3090 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3091 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3093 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3094 Bengt-Inge Larsson.) This is currently an approximation; a better version
3095 will require the zic and localtime fixes mentioned below, and the plan is
3096 to wait for a while until at least the zic fixes propagate.
3098 Changes affecting code
3100 'zic' and 'localtime' no longer reject locations needing four transitions
3101 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3102 Also, 'zic' avoids some unlikely failures due to integer overflow.
3104 Changes affecting build procedure
3106 'make check' now detects Rule lines defined but never used.
3107 The NZAQ rules, an instance of this problem, have been removed.
3109 Changes affecting commentary and documentation
3111 Fix Tuesday/Thursday typo in description of time in Israel.
3112 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3114 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3115 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3116 library supports them.
3118 Add comments about Johnston Island time in the 1960s.
3119 (Thanks to Lyle McElhaney.)
3121 Morocco's 2014 DST start will be as predicted.
3122 (Thanks to Sebastien Willemijns.)
3125 Release 2014a - 2014-03-07 23:30:29 -0800
3127 Changes affecting near-future timestamps
3129 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3130 the heads-up, and to Tim Parenti for simplifying the update.)
3132 Changes affecting past timestamps
3134 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
3135 (Thanks to Steffen Thorsen.)
3137 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3138 (not 1992-01-01), and observed DST during the entire next winter.
3139 (Thanks to Vladimir in Moscow via Alois Treindl.)
3141 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3142 (Thanks to Avigdor Finkelstein.)
3144 Changes affecting code
3146 A uninitialized-storage bug in 'localtime' has been fixed.
3147 (Thanks to Logan Chien.)
3149 Changes affecting the build procedure
3151 The settings for 'make check_web' now default to Ubuntu 13.10.
3153 Changes affecting commentary and documentation
3155 The boundary of the US Pacific time zone is given more accurately.
3156 (Thanks to Alan Mintz.)
3158 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3160 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3162 Better descriptions of countries with same time zone history as
3163 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3165 Several changes affect tz-link.htm, the main web page.
3167 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3170 Mention xCal (Internet RFC 6321) and jCal.
3172 Microsoft has some support for tz database names.
3174 CLDR data formats include both XML and JSON.
3176 Mention Maggiolo's map of solar vs standard time.
3177 (Thanks to Arthur David Olson.)
3179 Mention TZ4Net. (Thanks to Matt Johnson.)
3181 Mention the timezone-olson Haskell package.
3183 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3185 Remove moribund links to daylight-savings-time.info and to
3186 Simple Timer + Clocks.
3188 Update two links. (Thanks to Oscar van Vlijmen.)
3190 Fix some formatting glitches, e.g., remove random newlines from
3191 abbr elements' title attributes.
3194 Release 2013i - 2013-12-17 07:25:23 -0800
3196 Changes affecting near-future timestamps:
3198 Jordan switches back to standard time at 00:00 on December 20, 2013.
3199 The 2006-2011 transition schedule is planned to resume in 2014.
3200 (Thanks to Steffen Thorsen.)
3202 Changes affecting past timestamps:
3204 In 2004, Cuba began DST on March 28, not April 4.
3205 (Thanks to Steffen Thorsen.)
3207 Changes affecting code
3209 The compile-time flag NOSOLAR has been removed, as nowadays the
3210 benefit of slightly shrinking runtime table size is outweighed by the
3211 cost of disallowing potential future updates that exceed old limits.
3213 Changes affecting documentation and commentary
3215 The files solar87, solar88, and solar89 are no longer distributed.
3216 They were a negative experiment - that is, a demonstration that
3217 tz data can represent solar time only with some difficulty and error.
3218 Their presence in the distribution caused confusion, as Riyadh
3219 civil time was generally not solar time in those years.
3221 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3224 Release 2013h - 2013-10-25 15:32:32 -0700
3226 Changes affecting current and future timestamps:
3228 Libya has switched its UT offset back to +02 without DST, instead
3229 of +01 with DST. (Thanks to Even Scharning.)
3231 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3232 (Thanks to Gwillim Law.)
3234 Changes affecting future timestamps:
3236 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3237 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3238 (Thanks to Steffen Thorsen.)
3240 Add entries for DST transitions in Morocco in the year 2038.
3241 This avoids some year-2038 glitches introduced in 2013g.
3242 (Thanks to Yoshito Umaoka for reporting the problem.)
3244 Changes affecting API
3246 The 'tzselect' command no longer requires the 'select' command,
3247 and should now work with /bin/sh on more platforms. It also works
3248 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3249 Patrick 'P. J.' McDermott and Alan Barrett.)
3251 Changes affecting code
3253 Fix localtime overflow bugs with 32-bit unsigned time_t.
3255 zdump no longer assumes sscanf returns maximal values on overflow.
3257 Changes affecting the build procedure
3259 The builder can specify which programs to use, if any, instead of
3260 'ar' and 'ranlib', and libtz.a is now built locally before being
3261 installed. (Thanks to Michael Forney.)
3263 A dependency typo in the 'zdump' rule has been fixed.
3264 (Thanks to Andrew Paprocki.)
3266 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3267 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3269 'make clean' no longer removes 'leapseconds', since it's
3270 host-independent and is part of the distribution.
3272 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3274 Changes affecting documentation and commentary
3276 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3277 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3279 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3280 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3281 longer maintained) and for old advisories. SOFA now does C.
3283 Release 2013g - 2013-09-30 21:08:26 -0700
3285 Changes affecting current and near-future timestamps
3287 Morocco now observes DST from the last Sunday in March to the last
3288 Sunday in October, not April to September respectively. (Thanks
3289 to Steffen Thorsen.)
3291 Changes affecting 'zic'
3293 'zic' now runs on platforms that lack both hard links and symlinks.
3294 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3295 Also, fix some bugs on platforms that lack hard links but have symlinks.
3297 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3298 to predict the far future, fixing a bug introduced in 2013e.
3300 Changes affecting the build procedure
3302 The 'leapseconds' file is again put into the tzdata tarball.
3303 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3304 Matt Burgess and Ian Abbott.) The timestamps of these and other
3305 dependent files in tarballs are adjusted more consistently.
3307 Changes affecting documentation and commentary
3309 The README file is now part of the data tarball as well as the code.
3310 It now states that files are public domain unless otherwise specified.
3311 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3312 Its details about the 1989 release moved to a place of honor near
3316 Release 2013f - 2013-09-24 23:37:36 -0700
3318 Changes affecting near-future timestamps
3320 Tocantins will very likely not observe DST starting this spring.
3321 (Thanks to Steffen Thorsen.)
3323 Jordan will likely stay at UT +03 indefinitely, and will not fall
3326 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3328 Changes affecting API
3330 The types of the global variables 'timezone' and 'altzone' (if present)
3331 have been changed back to 'long'. This is required for 'timezone'
3332 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3333 These variables were originally 'long' in the tz code, but were
3334 mistakenly changed to 'time_t' in 1987; nobody reported the
3335 incompatibility until now. The difference matters on x32, where
3336 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3338 Changes affecting the build procedure
3340 Avoid long strings in leapseconds.awk to work around a mawk bug.
3341 (Thanks to Cyril Baurand.)
3343 Changes affecting documentation and commentary
3345 New file 'NEWS' that contains release notes like this one.
3347 Paraguay's law does not specify DST transition time; 00:00 is customary.
3348 (Thanks to Waldemar Villamayor-Venialbo.)
3350 Minor capitalization fixes.
3352 Changes affecting version-control only
3354 The experimental GitHub repository now contains annotated and
3355 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3356 Releases are tagged starting with 2012e; earlier releases were
3357 done differently, and tags would either not have a simple name or
3358 not exactly match what was released.
3360 'make set-timestamps' is now simpler and a bit more portable.
3363 Release 2013e - 2013-09-19 23:50:04 -0700
3365 Changes affecting near-future timestamps
3367 This year Fiji will start DST on October 27, not October 20.
3368 (Thanks to David Wheeler for the heads-up.) For now, guess that
3369 Fiji will continue to spring forward the Sunday before the fourth
3372 Changes affecting current and future time zone abbreviations
3374 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3375 time zone abbreviations since 1932. (Thanks to George Ziegler,
3376 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3377 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3378 Asia/Makassar, and Asia/Pontianak.
3380 Use ART (UT -03, standard time), rather than WARST (also -03, but
3381 daylight saving time) for San Luis, Argentina since 2009.
3383 Changes affecting Godthåb timestamps after 2037 if version mismatch
3385 Allow POSIX-like TZ strings where the transition time's hour can
3386 range from -167 through 167, instead of the POSIX-required 0
3387 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3388 new Fiji rules. This is a more-compact way to represent
3389 far-future timestamps for America/Godthab, America/Santiago,
3390 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3391 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3392 this change. (Derived from a suggestion by Arthur David Olson.)
3394 Allow POSIX-like TZ strings where daylight saving time is in
3395 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3396 Argentina Summer Time all year. This supports a more-compact way
3397 to represent the 2013d data for America/Argentina/San_Luis.
3398 Because of the change for San Luis noted above this change does not
3399 affect the current data. (Thanks to Andrew Main (Zefram) for
3400 suggestions that improved this change.)
3402 Where these two TZ changes take effect, there is a minor extension
3403 to the tz file format in that it allows new values for the
3404 embedded TZ-format string, and the tz file format version number
3405 has therefore been increased from 2 to 3 as a precaution.
3406 Version-2-based client code should continue to work as before for
3407 all timestamps before 2038. Existing version-2-based client code
3408 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3409 files, and typically works in practice even for timestamps after
3410 2037; the only known exception is America/Godthab.
3412 Changes affecting timestamps before 1970
3414 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3415 some errors before 1947.
3417 Some zones have been turned into links, when they differ from existing
3418 zones only in older data entries that were likely invented or that
3419 differ only in LMT or transitions from LMT. These changes affect
3420 only timestamps before 1943. The affected zones are:
3421 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3422 America/Grenada, America/Guadeloupe, America/Marigot,
3423 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3424 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3425 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3426 confirming that the old Europe/Vaduz zone was wrong and the new
3427 link is better for WWII-era times.)
3429 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3430 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3433 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3434 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3437 Change the date of the circa-1850 Zurich transition from 1849-09-12
3438 to 1853-07-16, overriding Shanks with data from Messerli about
3439 postal and telegraph time in Switzerland.
3441 Changes affecting time zone abbreviations before 1970
3443 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3444 as Jakarta was called Batavia back then.
3446 Changes affecting API
3448 The 'zic' command now outputs a dummy transition when far-future
3449 data can't be summarized using a TZ string, and uses a 402-year
3450 window rather than a 400-year window. For the current data, this
3451 affects only the Asia/Tehran file. It does not affect any of the
3452 timestamps that this file represents, so zdump outputs the same
3453 information as before. (Thanks to Andrew Main (Zefram).)
3455 The 'date' command has a new '-r' option, which lets you specify
3456 the integer time to display, a la FreeBSD.
3458 The 'tzselect' command has two new options '-c' and '-n', which lets you
3459 select a zone based on latitude and longitude.
3461 The 'zic' command's '-v' option now warns about constructs that
3462 require the new version-3 binary file format. (Thanks to Arthur
3463 David Olson for the suggestion.)
3465 Support for floating-point time_t has been removed.
3466 It was always dicey, and POSIX no longer requires it.
3467 (Thanks to Eric Blake for suggesting to the POSIX committee to
3468 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3469 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3470 bugs and elucidating some of the corners of the old floating-point
3473 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3474 changed back to the old practice of using 'long' to represent UT
3475 offsets. This had been inadvertently and mistakenly changed to
3476 'int_fast32_t'. (Thanks to Christos Zoulas.)
3478 The code avoids undefined behavior on integer overflow in some
3479 more places, including gmtime, localtime, mktime and zdump.
3481 Changes affecting the zdump utility
3483 zdump now outputs "UT" when referring to Universal Time, not "UTC".
3484 "UTC" does not make sense for timestamps that predate the introduction
3485 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
3486 for clarifying UT vs UTC.)
3488 Data changes affecting behavior of tzselect and similar programs
3490 Country code BQ is now called the more-common name "Caribbean Netherlands"
3491 rather than the more-official "Bonaire, St Eustatius & Saba".
3493 Remove from zone.tab the names America/Montreal, America/Shiprock,
3494 and Antarctica/South_Pole, as they are equivalent to existing
3495 same-country-code zones for post-1970 timestamps. The data entries for
3496 these names are unchanged, so the names continue to work as before.
3498 Changes affecting code internals
3500 zic -c now runs way faster on 64-bit hosts when given large numbers.
3502 zic now uses vfprintf to avoid allocating and freeing some memory.
3504 tzselect now computes the list of continents from the data,
3505 rather than have it hard-coded.
3507 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3509 Changes affecting the build procedure
3511 The 'leapseconds' file is now generated automatically from a
3512 new file 'leap-seconds.list', which is a copy of
3513 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3514 A new source file 'leapseconds.awk' implements this.
3515 The goal is simplification of the future maintenance of 'leapseconds'.
3517 When building the 'posix' or 'right' subdirectories, if the
3518 subdirectory would be a copy of the default subdirectory, it is
3519 now made a symbolic link if that is supported. This saves about
3520 2 MB of file system space.
3522 The links America/Shiprock and Antarctica/South_Pole have been
3523 moved to the 'backward' file. This affects only nondefault builds
3524 that omit 'backward'.
3526 Changes affecting version-control only
3528 .gitignore now ignores 'date'.
3530 Changes affecting documentation and commentary
3532 Changes to the 'tzfile' man page
3534 It now mentions that the binary file format may be extended in
3535 future versions by appending data.
3537 It now refers to the 'zdump' and 'zic' man pages.
3539 Changes to the 'zic' man page
3541 It lists conditions that elicit a warning with '-v'.
3543 It says that the behavior is unspecified when duplicate names
3544 are given, or if the source of one link is the target of another.
3546 Its examples are updated to match the latest data.
3548 The definition of white space has been clarified slightly.
3549 (Thanks to Michael Deckers.)
3551 Changes to the 'Theory' file
3553 There is a new section about the accuracy of the tz database,
3554 describing the many ways that errors can creep in, and
3555 explaining why so many of the pre-1970 timestamps are wrong or
3556 misleading (thanks to Steve Allen, Lester Caine, and Garrett
3557 Wollman for discussions that contributed to this).
3559 The 'Theory' file describes LMT better (this follows a
3560 suggestion by Guy Harris).
3562 It refers to the 2013 edition of POSIX rather than the 2004 edition.
3564 It's mentioned that excluding 'backward' should not affect the
3565 other data, and it suggests at least one zone.tab name per
3566 inhabited country (thanks to Stephen Colebourne).
3568 Some longstanding restrictions on names are documented, e.g.,
3569 'America/New_York' precludes 'America/New_York/Bronx'.
3571 It gives more reasons for the 1970 cutoff.
3573 It now mentions which time_t variants are supported, such as
3574 signed integer time_t. (Thanks to Paul Goyette for reporting
3575 typos in an experimental version of this change.)
3577 (Thanks to Philip Newton for correcting typos in these changes.)
3579 Documentation and commentary is more careful to distinguish UT in
3580 general from UTC in particular. (Thanks to Steve Allen.)
3582 Add a better source for the Zurich 1894 transition.
3583 (Thanks to Pierre-Yves Berger.)
3585 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
3588 Release 2013d - 2013-07-05 07:38:01 -0700
3590 Changes affecting future timestamps:
3592 Morocco's midsummer transitions this year are July 7 and August 10,
3593 not July 9 and August 8. (Thanks to Andrew Paprocki.)
3595 Israel now falls back on the last Sunday of October.
3596 (Thanks to Ephraim Silverberg.)
3598 Changes affecting past timestamps:
3600 Specify Jerusalem's location more precisely; this changes the pre-1880
3603 Changing affecting metadata only:
3605 Fix typos in the entries for country codes BQ and SX.
3607 Changes affecting code:
3609 Rework the code to fix a bug with handling Australia/Macquarie on
3610 32-bit hosts (thanks to Arthur David Olson).
3612 Port to platforms like NetBSD, where time_t can be wider than long.
3614 Add support for testing time_t types other than the system's.
3615 Run 'make check_time_t_alternatives' to try this out.
3616 Currently, the tests fail for unsigned time_t;
3617 this should get fixed at some point.
3619 Changes affecting documentation and commentary:
3621 Deemphasize the significance of national borders.
3623 Update the zdump man page.
3625 Remove obsolete NOID comment (thanks to Denis Excoffier).
3627 Update several URLs and comments in the web pages.
3629 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3631 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3634 Release 2013c - 2013-04-19 16:17:40 -0700
3636 Changes affecting current and future timestamps:
3638 Palestine observed DST starting March 29, 2013. (Thanks to
3639 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
3640 with the predicted rules being the last Thursday in March at 24:00
3641 to the first Friday on or after September 21 at 01:00.
3643 Assume that the recent change to Paraguay's DST rules is permanent,
3644 by moving the end of DST to the 4th Sunday in March every year.
3645 (Thanks to Carlos Raúl Perasso.)
3647 Changes affecting past timestamps:
3649 Fix some historical data for Palestine to agree with that of
3650 timeanddate.com, as follows:
3652 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3655 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3658 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3660 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
3662 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
3664 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
3666 Fix times of habitation for Macquarie to agree with the Tasmania
3667 Parks & Wildlife Service history, which indicates that permanent
3668 habitation was 1899-1919 and 1948 on.
3670 Changing affecting metadata only:
3672 Macquarie Island is politically part of Australia, not Antarctica.
3673 (Thanks to Tobias Conradi.)
3675 Sort Macquarie more-consistently with other parts of Australia.
3676 (Thanks to Tim Parenti.)
3679 Release 2013b - 2013-03-10 22:33:40 -0700
3681 Changes affecting current and future timestamps:
3683 Haiti uses US daylight-saving rules this year, and presumably future years.
3684 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
3686 Paraguay will end DST on March 24 this year.
3687 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
3689 Morocco does not observe DST during Ramadan;
3690 try to predict Ramadan in Morocco as best we can.
3691 (Thanks to Erik Homoet for the heads-up.)
3693 Changes affecting commentary:
3695 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
3696 Update URL for Solaris. Mention Internet RFC 6557.
3697 Update Internet RFCs 2445->5545, 2822->5322.
3698 Switch from FTP to HTTP for Internet RFCs.
3701 Release 2013a - 2013-02-27 09:20:35 -0800
3703 Change affecting binary data format:
3705 The zone offset at the end of version-2-format zone files is now
3706 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
3708 Changes affecting current and future timestamps:
3710 Chile's 2013 rules, and we guess rules for 2014 and later, will be
3711 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
3712 (Thanks to Steffen Thorsen and Robert Elz.)
3714 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
3715 (Thanks to Tobias Conradi and Arthur David Olson.)
3717 Many changes affect historical timestamps before 1940.
3718 These were deduced from: Milne J. Civil time. Geogr J. 1899
3719 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
3721 Changes affecting the code:
3723 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
3724 the data). (Thanks to Arthur David Olson.)
3726 Fix localtime bug when time_t is unsigned and data files were generated
3727 by a signed time_t system. (Thanks to Doug Bailey for reporting and
3728 to Arthur David Olson for fixing.)
3730 Allow the email address for bug reports to be set by the packager.
3731 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
3733 Update HTML checking to be compatible with Ubuntu 12.10.
3735 Check that files are a safe subset of ASCII. At some point we may
3736 relax this requirement to a safe subset of UTF-8. Without the
3737 check, some non-UTF-8 encodings were leaking into the distribution.
3741 Restore a comment about copyright notices that was inadvertently deleted.
3742 (Thanks to Arthur David Olson.)
3744 Improve the commentary about which districts observe what times
3745 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
3747 Add web page links to tz.js.
3749 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
3752 Release 2012j - 2012-11-12 18:34:49 -0800
3754 Libya moved to CET this weekend, but with DST planned next year.
3755 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3757 Signatures now have the extension .asc, not .sign, as that's more
3758 standard. (Thanks to Phil Pennock.)
3760 The output of 'zdump --version', and of 'zic --version', now
3761 uses a format that is more typical for --version.
3762 (Thanks to Joseph S. Myers.)
3764 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
3765 now uses tz@iana.org rather than the old elsie address.
3767 zic -v now complains about abbreviations that are less than 3
3768 or more than 6 characters, as per Posix. Formerly, it checked
3769 for abbreviations that were more than 3.
3771 'make public' no longer puts its temporary directory under /tmp,
3772 and uses the just-built zic rather than the system zic.
3774 Various fixes to documentation and commentary.
3777 Release 2012i - 2012-11-03 12:57:09 -0700
3779 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
3781 Linker flags can now be specified via LDFLAGS.
3782 AWK now defaults to 'awk', not 'nawk'.
3783 The shell in tzselect now defaults to /bin/bash, but this can
3784 be overridden by specifying KSHELL.
3785 The main web page now mentions the unofficial GitHub repository.
3786 (Thanks to Mike Frysinger.)
3788 Tarball signatures can now be built by running 'make signatures'.
3789 There are also new makefile rules 'tarballs', 'check_public', and
3790 separate makefile rules for each tarball and signature file.
3791 A few makefile rules are now more portable to strict POSIX.
3793 The main web page now lists the canonical IANA URL.
3796 Release 2012h - 2012-10-26 22:49:10 -0700
3798 Bahia no longer has DST. (Thanks to Kelley Cook.)
3800 Tocantins has DST. (Thanks to Rodrigo Severo.)
3802 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
3804 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
3808 More C modernization, except that at Arthur David Olson's suggestion
3809 the instances of 'register' were kept.
3812 Release 2012g - 2012-10-17 20:59:45 -0700
3814 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
3816 Palestine fall 2012. (Thanks to Steffen Thorsen.)
3820 To attack the version-number problem, this release ships the file
3821 'Makefile' (which contains the release number) in both the tzcode and
3822 the tzdata tarballs. The two Makefiles are identical, and should be
3823 identical in any matching pair of tarballs, so it shouldn't matter
3824 which order you extract the tarballs. Perhaps we can come up with a
3825 better version-number scheme at some point; this scheme does have the
3826 virtue of not adding more files.
3829 Release 2012f - 2012-09-12 23:17:03 -0700
3831 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
3832 20 this year. (Thanks to Steffen Thorsen.)
3835 Release 2012e - 2012-08-02 20:44:55 -0700
3837 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
3838 (Thanks to Steffen Thorsen.)
3840 * Use a single version number for both code and data.
3842 * .gitignore: New file.
3844 * Remove trailing white space.
3847 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
3849 Changes for Morocco's timestamps, which take effect in a couple of
3850 hours, along with infrastructure changes to accommodate how the tz
3851 code and data are released on IANA.
3854 Release data2012c - 2012-03-27 12:17:25 -0400
3857 Summer time changes for Morocco (to start late April 2012)
3860 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
3863 Haiti following US/Canada rules for 2012 (and we're assuming,
3864 for now anyway, for the future).
3867 Release 2012b - 2012-03-02 12:29:15 +0700
3869 There is just one change to tzcode2012b (compared with 2012a):
3870 the Makefile that was accidentally included with 2012a has been
3871 replaced with the version that should have been there, which is
3872 identical with the previous version (from tzcode2011i).
3874 There are just two changes in tzdata2012b compared with 2012a.
3876 Most significantly, summer time in Cuba has been delayed 3 weeks
3877 (now starts April 1 rather than March 11). Since Mar 11 (the old start
3878 date, as listed in 2012a) is just a little over a week away, this
3881 Less importantly, an excess tab in one of the changes in zone.tab
3882 in 2012a has been removed.
3885 Release 2012a - 2012-03-01 18:28:10 +0700
3887 The changes in tzcode2012a (compared to the previous version, 2011i)
3888 are entirely to the README and tz-art.htm and tz-link.htm files, if
3889 none of those concern you, you can ignore the code update. The changes
3890 reflect the changed addresses for the mailing list and the code and
3891 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
3892 has been added to tz-link.htm).
3894 In tzdata2012a (compared to the previous release, which was 2011n)
3895 the major changes are:
3896 Chile 2011/2012 and 2012/2013 summer time date adjustments.
3897 Falkland Islands onto permanent summer time (we're assuming for the
3898 foreseeable future, though 2012 is all we're fairly certain of.)
3899 Armenia has abolished Summer Time.
3900 Tokelau jumped the International Date Line back last December
3901 (just the same as their near neighbour, Samoa).
3902 America/Creston is a new zone for a small area of British Columbia
3903 There will be a leapsecond 2012-06-30 23:59:60 UTC.
3905 Other minor changes are:
3906 Corrections to 1918 Canadian summer time end dates.
3907 Updated URL for UK time zone history (in comments)
3908 A few typos in Le Corre's list of free French place names (comments)
3911 Release data2011n - 2011-10-30 14:57:54 +0700
3913 There are three changes of note - most urgently, Cuba (America/Havana)
3914 has extended summer time by two weeks, now to end on Nov 13, rather than
3915 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
3916 (Europe/Tiraspol) decided not to split from the rest of Moldova after
3917 all, and consequently that zone has been removed (again) and reinstated
3918 in the "backward" file as a link to Europe/Chisinau. And third, the
3919 end date for Fiji's summer time this summer was moved forward from the
3920 earlier planned Feb 26, to Jan 22.
3922 Apart from that, Moldova (MD) returns to a single entry in zone.tab
3923 (and the incorrect syntax that was in the 2011m version of that file
3924 is so fixed - it would have been fixed in a different way had this
3925 change not happened - that's the "missing" sccs version id).
3928 Release data2011m - 2011-10-24 21:42:16 +0700
3930 In particular, the typos in comments in the data (2011-11-17 should have
3931 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
3932 Tim Parenti noted) have been fixed, and the change for Ukraine has been
3933 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
3934 Tim Parenti, and also Denys Gavrysh)
3936 In addition, I added Europe/Tiraspol to zone.tab.
3938 This time, all the files have new version numbers... (including the files
3939 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
3940 version numbers there...)
3943 Release data2011l - 2011-10-10 11:15:43 +0700
3945 There are just 2 changes that cause different generated tzdata files from
3946 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
3947 is included, but commented out. Compared with the diff I sent out last week,
3948 this version also includes attributions for the sources for the changes
3949 (in much the same format as ado used, but the html tags have not been
3950 checked, verified, or used in any way at all, so if there are errors there,
3951 please let me know.)
3954 Release data2011k - 2011-09-20 17:54:03 -0400
3959 Release data2011j - 2011-09-12 09:22:49 -0400
3961 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
3962 Tanzania); there are also two spelling corrections to comments in
3963 the australasia file (with thanks to Christos Zoulas).
3966 Release 2011i - 2011-08-29 05:56:32 -0400
3971 Release data2011h - 2011-06-15 18:41:48 -0400
3973 Russia and Curaçao changes
3976 Release 2011g - 2011-04-25 09:07:22 -0400
3978 update the rules for Egypt to reflect its abandonment of DST this year
3981 Release 2011f - 2011-04-06 17:14:53 -0400
3986 Release 2011e - 2011-03-31 16:04:38 -0400
3988 Morocco, Chile, and tz-link changes
3991 Release 2011d - 2011-03-14 09:18:01 -0400
3993 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
3996 Release 2011c - 2011-03-07 09:30:09 -0500
3998 These do affect current timestamps in Chile and Annette Island, Canada.
4001 Release 2011b - 2011-02-07 08:44:50 -0500
4006 Release 2011a - 2011-01-24 10:30:16 -0500
4011 Release data2010o - 2010-11-01 09:18:23 -0400
4013 change to the end of DST in Fiji in 2011
4016 Release 2010n - 2010-10-25 08:19:17 -0400
4021 Release 2010m - 2010-09-27 09:24:48 -0400
4023 Hong Kong, Vostok, and zic.c changes
4026 Release 2010l - 2010-08-16 06:57:25 -0400
4031 Release 2010k - 2010-07-26 10:42:27 -0400
4036 Release 2010j - 2010-05-10 09:07:48 -0400
4038 changes for Bahía de Banderas and for version naming
4041 Release data2010i - 2010-04-16 18:50:45 -0400
4043 the end of DST in Morocco on 2010-08-08
4046 Release data2010h - 2010-04-05 09:58:56 -0400
4051 Release data2010g - 2010-03-24 11:14:53 -0400
4056 Release 2010f - 2010-03-22 09:45:46 -0400
4061 Release data2010e - 2010-03-08 14:24:27 -0500
4063 corrects the Dhaka bug found by Danvin Ruangchan
4066 Release data2010d - 2010-03-06 07:26:01 -0500
4071 Release 2010c - 2010-03-01 09:20:58 -0500
4073 changes including KRE's suggestion for earlier initialization of
4074 "goahead" and "goback" structure elements
4077 Release code2010a - 2010-02-16 10:40:04 -0500
4082 Release data2010b - 2010-01-20 12:37:01 -0500
4087 Release data2010a - 2010-01-18 08:30:04 -0500
4092 Release data2009u - 2009-12-26 08:32:28 -0500
4094 changes to DST in Bangladesh
4097 Release 2009t - 2009-12-21 13:24:27 -0500
4102 Release data2009s - 2009-11-14 10:26:32 -0500
4104 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4107 Release 2009r - 2009-11-09 10:10:31 -0500
4109 "antarctica" and "tz-link.htm" changes
4112 Release 2009q - 2009-11-02 09:12:40 -0500
4114 with two corrections as reported by Eric Muller and Philip Newton
4117 Release data2009p - 2009-10-23 15:05:27 -0400
4119 Argentina (including San Luis) changes (with the correction from
4123 Release data2009o - 2009-10-14 16:49:38 -0400
4125 Samoa (commentary only), Pakistan, and Bangladesh changes
4128 Release data2009n - 2009-09-22 15:13:38 -0400
4130 added commentary for Argentina and a change to the end of DST in
4134 Release data2009m - 2009-09-03 10:23:43 -0400
4136 Samoa and Palestine changes
4139 Release data2009l - 2009-08-14 09:13:07 -0400
4141 Samoa (comments only) and Egypt
4144 Release 2009k - 2009-07-20 09:46:08 -0400
4149 Release data2009j - 2009-06-15 06:43:59 -0400
4151 Bangladesh change (with a short turnaround since the DST change is
4155 Release 2009i - 2009-06-08 09:21:22 -0400
4157 updating for DST in Bangladesh this year
4160 Release 2009h - 2009-05-26 09:19:14 -0400
4165 Release data2009g - 2009-04-20 16:34:07 -0400
4170 Release data2009f - 2009-04-10 11:00:52 -0400
4172 correct DST in Pakistan
4175 Release 2009e - 2009-04-06 09:08:11 -0400
4180 Release 2009d - 2009-03-23 09:38:12 -0400
4182 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4185 Release data2009c - 2009-03-16 09:47:51 -0400
4187 change to the start of Cuban DST
4190 Release 2009b - 2009-02-09 11:15:22 -0500
4195 Release 2009a - 2009-01-21 10:09:39 -0500
4200 Release data2008i - 2008-10-21 12:10:25 -0400
4202 southamerica and zone.tab files, with Argentina DST rule changes and
4203 United States zone reordering and recommenting
4206 Release 2008h - 2008-10-13 07:33:56 -0400
4211 Release 2008g - 2008-10-06 09:03:18 -0400
4213 Fix a broken HTML anchor and update Brazil's DST transitions;
4214 there's also a slight reordering of information in tz-art.htm.
4217 Release data2008f - 2008-09-09 22:33:26 -0400
4222 Release 2008e - 2008-07-28 14:11:17 -0400
4224 changes by Arthur David Olson and Jesper Nørgaard Welen
4227 Release data2008d - 2008-07-07 09:51:38 -0400
4229 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4232 Release data2008c - 2008-05-19 17:48:03 -0400
4234 Pakistan, Morocco, and Mongolia
4237 Release data2008b - 2008-03-24 08:30:59 -0400
4239 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4243 Release 2008a - 2008-03-08 05:42:16 -0500
4248 Release 2007k - 2007-12-31 10:25:22 -0500
4250 most importantly, changes to the "southamerica" file based on
4251 Argentina's readoption of daylight saving time
4254 Release 2007j - 2007-12-03 09:51:01 -0500
4256 1. eliminate the "P" (parameter) macro;
4258 2. the "noncontroversial" changes circulated on the time zone
4259 mailing list (less the changes to "logwtmp.c");
4261 3. eliminate "too many transition" errors when "min" is used in time
4264 4. changes by Paul Eggert (including updated information for Venezuela).
4267 Release data2007i - 2007-10-30 10:28:11 -0400
4269 changes for Cuba and Syria
4272 Release 2007h - 2007-10-01 10:05:51 -0400
4274 changes by Paul Eggert, as well as an updated link to the ICU
4275 project in tz-link.htm
4278 Release 2007g - 2007-08-20 10:47:59 -0400
4280 changes by Paul Eggert
4282 The "leapseconds" file has been updated to incorporate the most
4283 recent International Earth Rotation and Reference Systems Service
4286 There's an addition to tz-art.htm regarding the television show "Medium".
4289 Release 2007f - 2007-05-07 10:46:46 -0400
4291 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4294 changes to zic.c to allow hour values greater than 24 (along with
4295 Paul's improved time value overflow checking)
4298 Release 2007e - 2007-04-02 10:11:52 -0400
4300 Syria and Honduras changes by Paul Eggert
4302 zic.c variable renaming changes by Arthur David Olson
4305 Release 2007d - 2007-03-20 08:48:30 -0400
4307 changes by Paul Eggert
4309 the elimination of white space at the ends of lines
4312 Release 2007c - 2007-02-26 09:09:37 -0500
4314 changes by Paul Eggert
4317 Release 2007b - 2007-02-12 09:34:20 -0500
4319 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4321 changes to the commentary in "leapseconds" reflecting the IERS
4322 announcement that there is to be no positive leap second at the end
4326 Release 2007a - 2007-01-08 12:28:29 -0500
4328 changes by Paul Eggert
4330 Derick Rethan's Asmara change
4332 Oscar van Vlijmen's Easter Island local mean time change
4334 symbolic link changes
4337 Release 2006p - 2006-11-27 08:54:27 -0500
4339 changes by Paul Eggert
4342 Release 2006o - 2006-11-06 09:18:07 -0500
4344 changes by Paul Eggert
4347 Release 2006n - 2006-10-10 11:32:06 -0400
4349 changes by Paul Eggert
4352 Release 2006m - 2006-10-02 15:32:35 -0400
4354 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4356 (minimalist) changes to zic.8 to clarify "until" information
4359 Release data2006l - 2006-09-18 12:58:11 -0400
4361 Paul's best-effort work on this coming weekend's Egypt time change
4364 Release 2006k - 2006-08-28 12:19:09 -0400
4366 changes by Paul Eggert
4369 Release 2006j - 2006-08-21 09:56:32 -0400
4371 changes by Paul Eggert
4374 Release code2006i - 2006-08-07 12:30:55 -0400
4378 Ken Pizzini's conversion script
4381 Release code2006h - 2006-07-24 09:19:37 -0400
4383 adds public domain notices to four files
4385 includes a fix for transition times being off by a second
4387 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4390 Release 2006g - 2006-05-08 17:18:09 -0400
4392 northamerica changes by Paul Eggert
4395 Release 2006f - 2006-05-01 11:46:00 -0400
4397 a missing version number problem is fixed (with thanks to Bradley
4398 White for catching the problem)
4401 Release 2006d - 2006-04-17 14:33:43 -0400
4403 changes by Paul Eggert
4405 added new items to tz-arts.htm that were found by Paul
4408 Release 2006c - 2006-04-03 10:09:32 -0400
4410 two sets of data changes by Paul Eggert
4412 a fencepost error fix in zic.c
4414 changes to zic.c and the "europe" file to minimize differences
4415 between output produced by the old 32-bit zic and the new 64-bit
4419 Release 2006b - 2006-02-20 10:08:18 -0500
4420 [tz32code2006b + tz64code2006b + tzdata2006b]
4424 All SCCS IDs were bumped to "8.1" for this release.
4427 Release 2006a - 2006-01-30 08:59:31 -0500
4429 changes by Paul Eggert (in particular, Indiana time zone moves)
4431 an addition to the zic manual page to describe how special-case
4432 transitions are handled
4435 Release 2005r - 2005-12-27 09:27:13 -0500
4437 Canadian changes by Paul Eggert
4439 They also add "<pre>" directives to time zone data files and reflect
4440 changes to warning message logic in "zdump.c" (but with calls to
4441 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4444 Release 2005q - 2005-12-13 09:17:09 -0500
4446 Nothing earth-shaking here:
4447 1. Electronic mail addresses have been removed.
4448 2. Casts of the return value of exit have been removed.
4449 3. Casts of the argument of is.* macros have been added.
4450 4. Indentation in one section of zic.c has been fixed.
4451 5. References to dead URLs in the data files have been dealt with.
4454 Release 2005p - 2005-12-05 10:30:53 -0500
4456 "systemv", "tz-link.htm", and "zdump.c" changes
4457 (less the casts of arguments to the is* macros)
4460 Release 2005o - 2005-11-28 10:55:26 -0500
4462 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4464 zdump.c lint fixes by Arthur David Olson
4467 Release 2005n - 2005-10-03 09:44:09 -0400
4469 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4473 Release 2005m - 2005-08-29 12:15:40 -0400
4475 changes by Paul Eggert (with a small tweak to the tz-art change)
4477 a declaration of an unused variable has been removed from zdump.c
4480 Release 2005l - 2005-08-22 12:06:39 -0400
4482 changes by Paul Eggert
4484 overflow/underflow checks by Arthur David Olson, minus changes to
4485 the "Theory" file about the pending addition of 64-bit data (I grow
4486 less confident of the changes being accepted with each passing day,
4487 and the changes no longer increase the data files nine-fold--there's
4488 less than a doubling in size by my local Sun's reckoning)
4491 Release 2005k - 2005-07-14 14:14:24 -0400
4493 The "leapseconds" file has been edited to reflect the recently
4494 announced leap second at the end of 2005.
4496 I've also deleted electronic mail addresses from the files as an
4500 Release 2005j - 2005-06-13 14:34:13 -0400
4502 These reflect changes to limit the length of time zone abbreviations
4503 and the characters used in those abbreviations.
4505 There are also changes to handle POSIX-style "quoted" timezone
4506 environment variables.
4508 The changes were circulated on the time zone mailing list; the only
4509 change since then was the removal of a couple of minimum-length of
4510 abbreviation checks.
4513 Release data2005i - 2005-04-21 15:04:16 -0400
4515 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4518 Release 2005h - 2005-04-04 11:24:47 -0400
4520 changes by Paul Eggert
4522 minor changes to Makefile and zdump.c to produce more useful output
4523 when doing a "make typecheck"
4526 Release 2005g - 2005-03-14 10:11:21 -0500
4528 changes by Paul Eggert (a change to current DST rules in Uruguay and
4529 an update to a link to time zone software)
4532 Release 2005f - 2005-03-01 08:45:32 -0500
4534 data and documentation changes by Paul Eggert
4537 Release 2005e - 2005-02-10 15:59:44 -0500
4542 Release code2005d - 2005-01-31 09:21:47 -0500
4544 make zic complain about links to links if the -v flag is used
4546 have "make public" do more code checking
4548 add an include to "localtime.c" for the benefit of gcc systems
4551 Release 2005c - 2005-01-17 18:36:29 -0500
4553 get better results when mktime runs on a system where time_t is double
4555 changes to the data files (most importantly to Paraguay)
4558 Release 2005b - 2005-01-10 09:19:54 -0500
4560 Get localtime and gmtime working on systems with exotic time_t types.
4562 Update the leap second commentary in the "leapseconds" file.
4565 Release 2005a - 2005-01-01 13:13:44 -0500
4570 Release code2004i - 2004-12-14 13:42:58 -0500
4572 Deal with systems where time_t is unsigned.
4575 Release code2004h - 2004-12-07 11:40:18 -0500
4577 64-bit-time_t changes
4580 Release 2004g - 2004-11-02 09:06:01 -0500
4582 update to Cuba (taking effect this weekend)
4584 other changes by Paul Eggert
4586 correction of the spelling of Oslo
4588 changed versions of difftime.c and private.h
4591 Release code2004f - 2004-10-21 10:25:22 -0400
4593 Cope with wide-ranging tm_year values.
4596 Release 2004e - 2004-10-11 14:47:21 -0400
4598 Brazil/Argentina/Israel changes by Paul Eggert
4600 changes to tz-link.htm by Paul
4602 one small fix to Makefile
4605 Release 2004d - 2004-09-22 08:27:29 -0400
4607 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4610 Release 2004c - 2004-08-11 12:06:26 -0400
4612 asctime-related changes
4614 (variants of) some of the documentation changes suggested by Paul Eggert
4617 Release 2004b - 2004-07-19 14:33:35 -0400
4619 data changes by Paul Eggert - most importantly, updates for Argentina
4622 Release 2004a - 2004-05-27 12:00:47 -0400
4624 changes by Paul Eggert
4626 Handle DST transitions that occur at the end of a month in some
4627 years but at the start of the following month in other years.
4629 Add a copy of the correspondence that's the basis for claims about
4630 DST in the Navajo Nation.
4633 Release 2003e - 2003-12-15 09:36:47 -0500
4635 changes by Arthur David Olson (primarily code changes)
4637 changes by Paul Eggert (primarily data changes)
4639 minor changes to "Makefile" and "northamerica" (in the latter case,
4640 optimization of the "Toronto" rules)
4643 Release 2003d - 2003-10-06 09:34:44 -0400
4645 changes by Paul Eggert
4648 Release 2003c - 2003-09-16 10:47:05 -0400
4650 Fix bad returns in zic.c's inleap function.
4651 Thanks to Bradley White for catching the problem!
4654 Release 2003b - 2003-09-16 07:13:44 -0400
4656 Add a "--version" option (and documentation) to the zic and zdump commands.
4658 changes to overflow/underflow checking in zic
4660 a localtime typo fix.
4662 Update the leapseconds and tz-art.htm files.
4665 Release 2003a - 2003-03-24 09:30:54 -0500
4667 changes by Paul Eggert
4669 a few additions and modifications to the tz-art.htm file
4672 Release 2002d - 2002-10-15 13:12:42 -0400
4674 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
4676 There's also a new time zone quote in "tz-art.htm".
4679 Release 2002c - 2002-04-04 11:55:20 -0500
4681 changes by Paul Eggert
4683 Change zic.c to avoid creating symlinks to files that don't exist.
4686 Release 2002b - 2002-01-28 12:56:03 -0500
4688 [These change notes are for Release 2002a, which was corrupted.
4689 2002b was a corrected version of 2002a.]
4691 changes by Paul Eggert
4693 Update the "leapseconds" file to note that there'll be no leap
4694 second at the end of June, 2002.
4696 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
4698 Change to "difftime.c" to avoid sizeof problems.
4701 Release 2001d - 2001-10-09 13:31:32 -0400
4703 changes by Paul Eggert
4706 Release 2001c - 2001-06-05 13:59:55 -0400
4708 changes by Paul Eggert and Andrew Brown
4711 Release 2001b - 2001-04-05 16:44:38 -0400
4713 changes by Paul Eggert (modulo jnorgard's typo fix)
4715 tz-art.htm has been HTMLified.
4718 Release 2001a - 2001-03-13 12:57:44 -0500
4720 changes by Paul Eggert
4722 An addition to the "leapseconds" file: comments with the text of the
4723 latest IERS leap second notice.
4725 Trailing white space has been removed from data file lines, and
4726 repeated spaces in "Rule Jordan" lines in the "asia" file have been
4730 Release 2000h - 2000-12-14 15:33:38 -0500
4732 changes by Paul Eggert
4734 one typo fix in the "art" file
4736 With providence, this is the last update of the millennium.
4739 Release 2000g - 2000-10-10 11:35:22 -0400
4741 changes by Paul Eggert
4743 correction of John Mackin's name submitted by Robert Elz
4745 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
4746 Emmy Awards broadcast.
4749 Release 2000f - 2000-08-10 09:31:58 -0400
4751 changes by Paul Eggert
4753 Added information in "tz-art.htm" on a Seinfeld reference to DST.
4755 Error checking and messages in the "yearistype" script have been
4759 Release 2000e - 2000-07-31 09:27:54 -0400
4761 data changes by Paul Eggert
4763 a change to the default value of the defined constant HAVE_STRERROR
4765 the addition of a Dave Barry quote on DST to the tz-arts file
4768 Release 2000d - 2000-04-20 15:43:04 -0400
4770 changes to the documentation and code of strftime for C99 conformance
4772 a bug fix for date.c
4774 These are based on (though modified from) changes by Paul Eggert.
4777 Release 2000c - 2000-03-04 10:31:43 -0500
4779 changes by Paul Eggert
4782 Release 2000b - 2000-02-21 12:16:29 -0500
4784 changes by Paul Eggert and Joseph Myers
4786 modest tweaks to the tz-art.htm and tz-link.htm files
4789 Release 2000a - 2000-01-18 09:21:26 -0500
4791 changes by Paul Eggert
4793 The two hypertext documents have also been renamed.
4796 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
4798 Paul Eggert's changes
4800 additions to the "zic" manual page and the "Arts.htm" file
4803 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
4808 Release data1999h - 1999-10-07 03:50:29 -0400
4810 changes by Paul Eggert to "europe" (most importantly, fixing
4811 Lithuania and Estonia)
4814 Release 1999g - 1999-09-28 11:06:18 -0400
4816 data changes by Paul Eggert (most importantly, the change for
4817 Lebanon that buys correctness for this coming Sunday)
4819 The "code" file contains changes to "Makefile" and "checktab.awk" to
4820 allow better checking of time zone files before they are published.
4823 Release 1999f - 1999-09-23 09:48:14 -0400
4825 changes by Arthur David Olson and Paul Eggert
4828 Release 1999e - 1999-08-17 15:20:54 -0400
4830 changes circulated by Paul Eggert, although the change to handling
4831 of DST-specifying timezone names has been commented out for now
4832 (search for "XXX" in "localtime.c" for details). These files also
4833 do not make any changes to the start of DST in Brazil.
4835 In addition to Paul's changes, there are updates to "Arts.htm" and
4839 Release 1999d - 1999-03-30 11:31:07 -0500
4841 changes by Paul Eggert
4843 The Makefile's "make public" rule has also been changed to do a test
4844 compile of each individual time zone data file (which should help
4845 avoid problems such as the one we had with Nicosia).
4848 Release 1999c - 1999-03-25 09:47:47 -0500
4850 changes by Paul Eggert, most importantly the change for Chile.
4853 Release 1999b - 1999-02-01 17:51:44 -0500
4855 changes by Paul Eggert
4857 code changes (suggested by Mani Varadarajan, mani at be.com) for
4858 correct handling of symbolic links when building using a relative directory
4860 code changes to generate correct messages for failed links
4862 updates to the URLs in Arts.htm
4865 Release 1999a - 1999-01-19 16:20:29 -0500
4867 error message internationalizations and corrections in zic.c and
4868 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
4872 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
4874 changes for Brazil, Chile, and Germany
4876 support for use of "24:00" in the input files for the time zone compiler
4879 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
4881 changes by Paul Eggert
4883 correction to a define in the "private.h" file
4886 Release data1998g - 1998-08-11 03:28:35 -0000
4887 [tzdata1998g.tar.gz is missing!]
4889 Lithuanian change provided by mgedmin at pub.osf.it
4891 Move creation of the GMT link with Etc/GMT to "etcetera" (from
4892 "backward") to ensure that the GMT file is created even where folks
4893 don't want the "backward" links (as suggested by Paul Eggert).
4896 Release data1998f - 1998-07-20 13:50:00 -0000
4897 [tzdata1998f.tar.gz is missing!]
4899 Update the "leapseconds" file to include the newly-announced
4900 insertion at the end of 1998.
4903 Release code1998f - 1998-06-01 10:18:31 -0400
4905 addition to localtime.c by Guy Harris
4908 Release 1998e - 1998-05-28 09:56:26 -0400
4910 The Makefile is changed to produce zoneinfo-posix rather than
4911 zoneinfo/posix, and to produce zoneinfo-leaps rather than
4914 data changes by Paul Eggert
4916 changes from Guy Harris to provide asctime_r and ctime_r
4918 A usno1998 file (substantially identical to usno1997) has been added.
4921 Release 1998d - 1998-05-14 11:58:34 -0400
4923 changes to comments (in particular, elimination of references to CIA maps).
4924 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
4925 where changes occur.
4928 Release 1998c - 1998-02-28 12:32:26 -0500
4930 changes by Paul Eggert (save the "French correction," on which I'll
4931 wait for the dust to settle)
4935 changes and additions to Arts.htm
4938 Release 1998b - 1998-01-17 14:31:51 -0500
4940 URL cleanups and additions
4943 Release 1998a - 1998-01-13 12:37:35 -0500
4945 changes by Paul Eggert
4948 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
4950 changes by Paul Eggert, with minor modifications from Arthur David
4951 Olson to make the files more browser friendly
4954 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
4956 minor changes to put "TZif" at the start of each timezone information file
4958 a rule has also been added to the Makefile so you can
4960 to just recompile the zone information files (rather than doing a
4961 full "make install" with its other effects).
4964 Release data1997i - 1997-10-07 08:45:38 -0400
4966 changes to Africa by Paul Eggert
4969 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
4971 corrections for Uruguay (and other locations)
4973 Arthur David Olson's simple-minded fix allowing mktime to both
4974 correctly handle leap seconds and correctly handle tm_sec values
4975 upon which arithmetic has been performed.
4978 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
4980 Paul Eggert's updates
4982 a small change to a function prototype;
4984 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
4985 include information on Around the World in Eighty Days.
4988 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
4990 fixes to zic's error handling
4992 changes inspired by the item circulated on Slovenia
4994 The description of Web resources has been HTMLified for browsing
4997 A new piece of tz-related music has been added to the "Music" file.
5000 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5002 Paul Eggert's latest suggestions
5005 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5007 changes to "zic.c" to correct performance of the "-s" option
5009 a new file "usno1997"
5012 Release data1997c - 1997-03-04 09:58:18 -0500
5017 Release 1997b - 1997-02-27 18:34:19 -0500
5019 The data file incorporates the 1997 leap second.
5021 The code file incorporates Arthur David Olson's take on the
5022 zic/multiprocessor/directory-creation situation.
5025 Release 1997a - 1997-01-21 09:11:10 -0500
5027 Paul Eggert's Antarctica (and other changes)
5029 Arthur David Olson finessed the "getopt" issue by checking against
5030 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5031 is returned while SunOS 5.5's manual says EOF is returned).
5034 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5036 Paul Eggert's latest changes
5039 Release code1996n - 1996-12-16 09:42:02 -0500
5041 link snapping fix from Bruce Evans (via Garrett Wollman)
5044 Release data1996m - 1996-11-24 02:37:34 -0000
5045 [tzdata1996m.tar.gz is missing!]
5047 Paul Eggert's batch of changes
5050 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5052 No functional changes here; the files have simply been changed to
5053 make more use of ISO style dates in comments. The names of the above
5054 files now include the year in full.
5057 Release code96l - 1996-09-08 17:12:20 -0400
5059 tzcode96k was missing a couple of pieces.
5062 Release 96k - 1996-09-08 16:06:22 -0400
5064 the latest round of changes from Paul Eggert
5066 the recent Year 2000 material
5069 Release code96j - 1996-07-30 13:18:53 -0400
5071 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5074 Release code96i - 1996-07-27 20:11:35 -0400
5076 Paul's suggested patch for strftime %V week numbers
5079 Release data96i - 1996-07-01 18:13:04 -0400
5081 "northamerica" and "europe" changes by Paul Eggert
5084 Release code96h - 1996-06-05 08:02:21 -0400
5086 fix for handling transitions specified in Universal Time
5088 Some "public domain" notices have also been added.
5091 Release code96g - 1996-05-16 14:00:26 -0400
5093 fix for the simultaneous-DST-and-zone-change challenge
5096 Release data96h - 1996-05-09 17:40:51 -0400
5098 changes by Paul Eggert
5101 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5102 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5104 The changes get us some of the way to fixing the problems noted in Paul
5105 Eggert's letter yesterday (in addition to a few others). The approach
5106 has been to make zic a bit smarter about figuring out what time zone
5107 abbreviations apply just after the time specified in the "UNTIL" part
5108 of a zone line. Putting the smarts in zic means avoiding having
5109 transition times show up in both "Zone" lines and "Rule" lines, which
5110 in turn avoids multiple transition time entries in time zone files.
5111 (This also makes the zic input files such as "europe" a bit shorter and
5112 should ease maintenance.)
5115 Release data96f - 1996-04-19 19:20:03 -0000
5116 [tzdata96f.tar.gz is missing!]
5118 The only changes are to the "northamerica" file; the time zone
5119 abbreviation for Denver is corrected to MST (and MDT), and the
5120 comments for Mexico have been updated.
5123 Release data96e - 1996-03-19 17:37:26 -0500
5125 Proposals by Paul Eggert, in particular the Portugal change that
5126 comes into play at the end of this month.
5129 Release data96d - 1996-03-18 20:49:39 -0500
5134 Release code96e - 1996-02-29 15:43:27 -0000
5135 [tzcode96e.tar.gz is missing!]
5137 internationalization changes and the fix to the documentation for strftime
5140 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5142 The "code" file simply updates Bob Kridle's electronic address.
5144 The "data" file updates rules for Mexico.
5147 Release data96b - 1996-01-27 15:44:42 -0500
5152 Release code96c - 1996-01-16 16:58:15 -0500
5154 leap-year streamlining and binary-search changes
5159 Release code96b - 1996-01-10 20:42:39 -0500
5161 fixes and enhancements from Paul Eggert, including code that
5162 emulates the behavior of recent versions of the SunOS "date"
5166 Release 96a - 1996-01-06 09:08:24 -0500
5170 fixes to strftime.c for correct ISO 8601 week number generation,
5171 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5172 numbers (which are not necessarily the same as calendar year numbers)
5175 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5177 The latest revisions from Paul Eggert are included, the usno1995
5178 file has been updated, and a new file ("WWW") covering useful URLs
5182 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5184 A simplification of a macro definition, a change to data for Sudan,
5185 and (for last minute shoppers) notes in the "Music" file on the CD
5189 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5191 (slightly reformatted) 8-bit-clean proposed patch
5193 minor patch: US/Eastern -> America/New_York
5195 snapshot of the USNO's latest data ("usno1995")
5197 some other minor cleanups
5200 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5201 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5205 support for 64-bit time_t's
5207 optimization in localtime.c
5210 Release code95e - 1995-10-13 13:23:57 -0400
5212 the mktime change to scan from future to past when trying to find time zone
5216 Release data95i - 1995-09-26 10:43:26 -0400
5218 For Canada/Central, guess that the Sun customer's "one week too
5219 early" was just a approximation, and the true error is one month
5220 too early. This is consistent with the rest of Canada.
5223 Release data95h - 1995-09-21 11:26:48 -0400
5225 latest changes from Paul Eggert
5228 Release code95d - 1995-09-14 11:14:45 -0400
5230 the addition of a "Music" file, which documents four recorded
5231 versions of the tune "Save That Time".
5234 Release data95g - 1995-09-01 17:21:36 -0400
5236 "yearistype" correction
5239 Release data95f - 1995-08-28 20:46:56 -0400
5241 Paul Eggert's change to the australasia file
5244 Release data95e - 1995-07-08 18:02:34 -0400
5246 The only change is a leap second at the end of this year.
5247 Thanks to Bradley White for forwarding news on the leap second.
5250 Release data95d - 1995-07-03 13:26:22 -0400
5252 Paul Eggert's changes
5255 Release data95c - 1995-07-02 19:19:28 -0400
5257 changes to "asia", "backward", "europe", and "southamerica"
5258 (read: northamericacentrics need not apply)
5261 Release code95c - 1995-03-13 14:00:46 -0500
5263 one-line fix for sign extension problems in detzcode
5266 Release 95b - 1995-03-04 11:22:38 -0500
5268 Minor changes in both:
5270 The "code" file contains a workaround for the lack of "unistd.h" in
5271 Microsoft C++ version 7.
5273 The "data" file contains a fixed "Link" for America/Shiprock.
5276 Release 94h - 1994-12-10 12:51:14 -0500
5280 * incorporate the changes to "zdump" and "date" to make changes to
5281 the "TZ" environment variable permanent;
5283 * incorporate the table changes by Paul Eggert;
5285 * include (and document) support for universal time specifications in
5286 data files - but do not (yet) include use of this feature in the
5289 Think of this as "TZ Classic" - the software has been set up not to break if
5290 universal time shows up in its input, and data entries have been
5291 left as is so as not to break existing implementations.
5294 Release data94f - 1994-08-20 12:56:09 -0400
5296 (with thanks!) the latest data updates from Paul Eggert
5299 Release data94e - 1994-06-04 13:13:53 -0400
5304 Release code94g - 1994-05-05 12:14:07 -0400
5306 fix missing "optind.c" and a reference to it in the Makefile
5309 Release code94f - 1994-05-05 13:00:33 -0000
5310 [tzcode94f.tar.gz is missing!]
5312 changes to avoid overflow in difftime, as well as changes to cope
5313 with the 52/53 challenge in strftime
5316 Release code94e - 1994-03-30 23:32:59 -0500
5318 change for the benefit of PCTS
5321 Release 94d - 1994-02-24 15:42:25 -0500
5323 Avoid clashes with POSIX semantics for zones such as GMT+4.
5325 Some other very minor housekeeping is also present.
5328 Release code94c - 1994-02-10 08:52:40 -0500
5330 Fix bug where mkdirs was broken unless you compile with
5331 -fwritable-strings (which is generally losing to do).
5334 Release 94b - 1994-02-07 10:04:33 -0500
5336 work by Paul Eggert who notes:
5338 I found another book of time zone histories by E W Whitman; it's not
5339 as extensive as Shanks but has a few goodies of its own. I used it
5340 to update the tables. I also fixed some more as a result of
5341 correspondence with Adam David and Peter Ilieve, and move some stray
5342 links from 'europe' to 'backward'. I corrected some scanning errors
5345 As far as the code goes, I fixed zic to allow years in the range
5346 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5347 And I cleaned up the zic documentation a little bit.
5350 Release data94a - 1994-02-03 08:58:54 -0500
5352 It simply incorporates the recently announced leap second into the
5356 Release 93g - 1993-11-22 17:28:27 -0500
5358 Paul Eggert has provided a good deal of historic information (based
5359 on Shanks), and there are some code changes to deal with the buglets
5360 that crawled out in dealing with the new information.
5363 Release 93f - 1993-10-15 12:27:46 -0400
5365 Paul Eggert's changes
5368 Release 93e - 1993-09-05 21:21:44 -0400
5370 This has updated data for Israel, England, and Kwajalein. There's
5371 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5372 Thanks to Paul Eggert and Peter Ilieve for the changes.
5375 Release 93d - 1993-06-17 23:34:17 -0400
5377 new fix and new data on Israel
5380 Release 93c - 1993-06-06 19:31:55 -0400
5385 Release 93b - 1993-02-02 14:53:58 -0500
5387 updated "leapseconds" file
5390 Release 93 - 1993-01-08 07:01:06 -0500
5392 At kre's suggestion, the package has been split in two - a code piece
5393 (which also includes documentation) that's only of use to folks who
5394 want to recompile things and a data piece useful to anyone who can
5397 The new version has a few changes to the data files, a few
5398 portability changes, and an off-by-one fix (with thanks to
5399 Tom Karzes at deshaw.com for providing a description and a
5403 Release 92c - 1992-11-21 17:35:36 -0000
5404 [tz92c.tar.Z is missing!]
5406 The fallout from the latest round of DST transitions.
5408 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5409 there's also a change to "zic.c" that makes it portable to more systems.
5412 Release 92 - 1992-04-25 18:17:03 -0000
5413 [tz92.tar.Z is missing!]
5415 By popular demand (well, at any rate, following a request by kre at munnari)
5418 The 1989 update of the time zone package featured:
5420 * POSIXization (including interpretation of POSIX-style TZ environment
5421 variables, provided by Guy Harris),
5422 * ANSIfication (including versions of "mktime" and "difftime"),
5423 * SVIDulation (an "altzone" variable)
5424 * MACHination (the "gtime" function)
5425 * corrections to some time zone data (including corrections to the rules
5426 for Great Britain and New Zealand)
5427 * reference data from the United States Naval Observatory for folks who
5428 want to do additional time zones
5429 * and the 1989 data for Saudi Arabia.
5431 (Since this code will be treated as "part of the implementation" in some
5432 places and as "part of the application" in others, there's no good way to
5433 name functions, such as timegm, that are not part of the proposed ANSI C
5434 standard; such functions have kept their old, underscore-free names in this
5437 And the "dysize" function has disappeared; it was present to allow
5438 compilation of the "date" command on old BSD systems, and a version of "date"
5439 is now provided in the package. The "date" command is not created when you
5440 "make all" since it may lack options provided by the version distributed with
5441 your operating system, or may not interact with the system in the same way
5442 the native version does.
5444 Since POSIX frowns on correct leap second handling, the default behavior of
5445 the "zic" command (in the absence of a "-L" option) has been changed to omit
5446 leap second information from its output files.
5452 This file contains copies of the part of each release announcement
5453 that talks about the changes in that release. The text has been
5454 adapted and reformatted for the purposes of this file.
5456 Traditionally a release R consists of a pair of tarball files,
5457 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5458 code2010a, data2012c) consist of just one or the other tarball, and a
5459 few (e.g., code2012c-data2012d) have tarballs with mixed version
5460 numbers. Recent releases also come in an experimental format
5461 consisting of a single tarball tzdb-R.tar.lz with extra data.
5463 Release timestamps are taken from the release's commit (for newer,
5464 Git-based releases), from the newest file in the tarball (for older
5465 releases, where this info is available) or from the email announcing
5466 the release (if all else fails; these are marked with a time zone
5467 abbreviation of -0000 and an "is missing!" comment).
5469 Earlier versions of the code and data were not announced on the tz
5470 list and are not summarized here.
5472 This file is in the public domain.