1 News for the tz database
3 Release 2022b - 2022-08-10 15:38:32 -0700
6 Chile's DST is delayed by a week in September 2022.
7 Iran no longer observes DST after 2022.
8 Rename Europe/Kiev to Europe/Kyiv.
10 Vanguard form now uses %z.
11 Finish moving duplicate-since-1970 zones to 'backzone'.
12 New build option PACKRATLIST
13 New tailored_tarballs target, replacing rearguard_tarballs
15 Changes to future timestamps
17 Chile's 2022 DST start is delayed from September 4 to September 11.
18 (Thanks to Juan Correa.)
20 Iran plans to stop observing DST permanently, after it falls back
21 on 2022-09-21. (Thanks to Ali Mirjamali.)
23 Changes to past timestamps
25 Finish moving to 'backzone' the location-based zones whose
26 timestamps since 1970 are duplicates; adjust links accordingly.
27 This change ordinarily affects only pre-1970 timestamps, and with
28 the new PACKRATLIST option it does not affect any timestamps.
29 In this round the affected zones are Antarctica/Vostok,
30 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
31 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
32 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
33 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
34 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
35 Pacific/Wake and Pacific/Wallis, and the affected links are
36 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
37 Pacific/Truk, and Pacific/Yap.
39 From fall 1994 through fall 1995, Shanks wrote that Crimea's
40 DST transitions were at 02:00 standard time, not at 00:00.
41 (Thanks to Michael Deckers.)
43 Iran adopted standard time in 1935, not 1946. In 1977 it observed
44 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
45 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
46 transition was on 05-27, not 03-21.
47 (Thanks to Roozbeh Pournader and Francis Santoni.)
49 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
50 considered DST, not standard time. Santiago and environs had moved
51 their clocks back to rejoin the rest of mainland Chile; put this
52 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
54 Some old, small clock transitions have been removed, as people at
55 the time did not change their clocks. This affects Asia/Hong_Kong
56 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
60 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
61 English now. Spelling of other names in Ukraine has not yet
62 demonstrably changed in common English practice so for now these
63 names retain old spellings, as in other countries (e.g.,
64 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
68 zic has a new option '-R @N' to output explicit transitions < N.
69 (Need suggested by Almaz Mingaleev.)
71 'zic -r @N' no longer outputs bad data when N < first transition.
72 (Problem introduced in 2021d and reported by Peter Krefting.)
74 zic now checks its input for NUL bytes and unterminated lines, and
75 now supports input line lengths up to 2048 (not 512) bytes.
77 gmtime and related code now use the abbreviation "UTC" not "GMT".
78 POSIX is being revised to require this.
80 When tzset and related functions set vestigial static variables
81 like tzname, they now prefer specified timestamps to unspecified ones.
82 (Problem reported by Almaz Mingaleev.)
84 zic no longer complains "can't determine time zone abbreviation to
85 use just after until time" when a transition to a new standard
86 time occurs simultanously with the first DST fallback transition.
88 Changes to build procedure
90 Source data in vanguard form now uses the %z notation, introduced
91 in release 2015f. For example, for America/Sao_Paulo vanguard
92 form contains the zone continuation line "-3:00 Brazil %z", which
93 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
94 used in main and rearguard forms. The plan is for the main form
95 to use %z eventually; in the meantime maintainers of zi parsers
96 are encouraged to test the parsers on vanguard.zi.
98 The Makefile has a new PACKRATLIST option to select a subset of
99 'backzone'. For example, 'make PACKRATDATA=backzone
100 PACKRATLIST=zone.tab' now generates TZif files identical to those
101 of the global-tz project.
103 The Makefile has a new tailored_tarballs target for generating
104 special-purpose tarballs. It generalizes and replaces the
105 rearguard_tarballs target and related targets and macros, which
108 'make install' now defaults LOCALTIME to Factory not GMT,
109 which means the default abbreviation is now "-00" not "GMT".
111 Remove the posix_packrat target, marked obsolescent in 2016a.
114 Release 2022a - 2022-03-15 23:02:01 -0700
117 Palestine will spring forward on 2022-03-27, not -03-26.
118 zdump -v now outputs better failure indications.
119 Bug fixes for code that reads corrupted TZif data.
121 Changes to future timestamps
123 Palestine will spring forward on 2022-03-27, not 2022-03-26.
124 (Thanks to Heba Hamad.) Predict future transitions for first
125 Sunday >= March 25. Additionally, predict fallbacks to be the first
126 Friday on or after October 23, not October's last Friday, to be more
127 consistent with recent practice. The first differing fallback
128 prediction is on 2025-10-24, not 2025-10-31.
130 Changes to past timestamps
132 From 1992 through spring 1996, Ukraine's DST transitions were at
133 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
135 Chile's Santiago Mean Time and its LMT precursor have been adjusted
136 eastward by 1 second to align with past and present law.
138 Changes to commentary
140 Add several references for Chile's 1946/1947 transitions, some of
141 which only affected portions of the country.
145 Fix bug when mktime gets confused by truncated TZif files with
146 unspecified local time. (Problem reported by Almaz Mingaleev.)
148 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
149 (Problem reported by Christos Zoulas.)
151 When reading a version 2 or later TZif file, the TZif reader now
152 validates the version 1 header and data block only enough to skip
153 over them, as recommended by RFC 8536 section 4. Also, the TZif
154 reader no longer mistakenly attempts to parse a version 1 TZIf
155 file header as a TZ string.
157 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
158 when local time and UT cannot be determined for a timestamp.
160 Changes to build procedure
162 Distribution tarballs now use standard POSIX.1-1988 ustar format
163 instead of GNU format. Although the formats are almost identical
164 for these tarballs, ustar headers' magic fields contain "ustar"
165 instead of "ustar ", and their version fields contain "00" instead
166 of " ". The two formats are planned to diverge more significantly
167 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
168 format becomes obsolete and the tarballs switch to pax format, an
169 extension of ustar. For details about these formats, please see
170 "pax - portable archive interchange", IEEE Std 1003.1-2017,
171 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
174 Release 2021e - 2021-10-21 18:41:00 -0700
176 Changes to future timestamps
178 Palestine will fall back 10-29 (not 10-30) at 01:00.
179 (Thanks to P Chan and Heba Hemad.)
182 Release 2021d - 2021-10-15 13:48:18 -0700
185 Fiji suspends DST for the 2021/2022 season.
186 'zic -r' marks unspecified timestamps with "-00".
188 Changes to future timestamps
190 Fiji will suspend observance of DST for the 2021/2022 season.
191 Assume for now that it will return next year. (Thanks to Jashneel
196 'zic -r' now uses "-00" time zone abbreviations for intervals
197 with UT offsets that are unspecified due to -r truncation.
198 This implements a change in draft Internet RFC 8536bis.
201 Release 2021c - 2021-10-01 14:21:49 -0700
204 Revert most 2021b changes to 'backward'.
205 Fix 'zic -b fat' bug in pre-1970 32-bit data.
206 Fix two Link line typos.
207 Distribute SECURITY file.
209 This release is intended as a bugfix release, to fix compatibility
210 problems and typos reported since 2021b was released.
212 Changes to Link directives
214 Revert almost all of 2021b's changes to the 'backward' file,
215 by moving Link directives back to where they were in 2021a.
216 Although 'zic' doesn't care which source file contains a Link
217 directive, some downstream uses ran into trouble with the move.
218 (Problem reported by Stephen Colebourne for Joda-Time.)
220 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
221 (problem reported by Chris Walton).
223 Fix 'backzone' typo that linked America/Virgin to the wrong
224 location (problem reported by Michael Deckers).
228 Fix a bug in 'zic -b fat' that caused old timestamps to be
229 mishandled in 32-bit-only readers (problem reported by Daniel
232 Changes to documentation
234 Distribute the SECURITY file (problem reported by Andreas Radke).
237 Release 2021b - 2021-09-24 16:23:00 -0700
240 Jordan now starts DST on February's last Thursday.
241 Samoa no longer observes DST.
242 Merge more location-based Zones whose timestamps agree since 1970.
243 Move some backward-compatibility links to 'backward'.
244 Rename Pacific/Enderbury to Pacific/Kanton.
245 Correct many pre-1993 transitions in Malawi, Portugal, etc.
246 zic now creates each output file or link atomically.
247 zic -L no longer omits the POSIX TZ string in its output.
248 zic fixes for truncation and leap second table expiration.
249 zic now follows POSIX for TZ strings using all-year DST.
250 Fix some localtime crashes and bugs in obscure cases.
251 zdump -v now outputs more-useful boundary cases.
252 tzfile.5 better matches a draft successor to RFC 8536.
255 This release is prompted by recent announcements by Jordan and Samoa.
256 It incorporates many other changes that had accumulated since 2021a.
257 However, it omits most proposed changes that merged all Zones
258 agreeing since 1970, as concerns were raised about doing too many of
259 these changes at once. It does keeps some of these changes in the
260 interest of making tzdb more equitable one step at a time; see
261 "Merge more location-based Zones" below.
263 Changes to future timestamps
265 Jordan now starts DST on February's last Thursday.
266 (Thanks to Steffen Thorsen.)
268 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
272 Rename Pacific/Enderbury to Pacific/Kanton. When we added
273 Enderbury in 1993, we did not know that it is uninhabited and that
274 Kanton (population two dozen) is the only inhabited location in
275 that timezone. The old name is now a backward-compatibility link.
277 Changes to past timestamps
279 Correct many pre-1993 transitions, fixing entries originally
280 derived from Shanks, Whitman, and Mundell. The fixes include:
281 - Barbados: standard time was introduced in 1911, not 1932; and
282 DST was observed in 1942-1944
283 - Cook Islands: In 1899 they switched from east to west of GMT,
284 celebrating Christmas for two days. They (and Niue) switched
285 to standard time in 1952, not 1901.
286 - Guyana: corrected LMT for Georgetown; the introduction of
287 standard time in 1911, not 1915; and corrections to 1975 and
289 - Kanton: uninhabited before 1937-08-31
290 - Niue: only observed -11:20 from 1952 through 1964, then went to
291 -11 instead of -11:30
292 - Portugal: DST was observed in 1950
293 - Tonga: corrected LMT; the introduction of standard time in 1945,
294 not 1901; and corrections to the transition from +12:20 to +13
296 Additional fixes to entries in the 'backzone' file include:
297 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
298 - The Gambia: 1933 and 1942 transitions
299 - Malawi: several 1911 through 1925 transitions
300 - Sierra Leone: several 1913 through 1941 transitions, and DST
301 was NOT observed in 1957 through 1962
302 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
305 Merge more location-based Zones whose timestamps agree since 1970,
306 as pre-1970 timestamps are out of scope. This is part of a
307 process that has been ongoing since 2013. This does not affect
308 post-1970 timestamps, and timezone historians who build with 'make
309 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
310 When merging, keep the most-populous location's data, and move
311 data for other locations to 'backzone' with a backward
312 link in 'backward'. For example, move America/Creston data to
313 'backzone' with a link in 'backward' from America/Phoenix because
314 the two timezones' timestamps agree since 1970; this change
315 affects some pre-1968 timestamps in America/Creston because
316 Creston and Phoenix disagreed before 1968. The affected Zones
317 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
318 America/Creston, America/Curacao, America/Nassau,
319 America/Port_of_Spain, Antarctica/DumontDUrville, and
322 Changes to maintenance procedure
324 The new file SECURITY covers how to report security-related bugs.
326 Several backward-compatibility links have been moved to the
327 'backward' file. These links, which range from Africa/Addis_Ababa
328 to Pacific/Saipan, are only for compatibility with now-obsolete
329 guidelines suggesting an entry for every ISO 3166 code.
330 The intercontinental convenience links Asia/Istanbul and
331 Europe/Nicosia have also been moved to 'backward'.
335 zic now creates each output file or link atomically,
336 possibly by creating a temporary file and then renaming it.
337 This avoids races where a TZ setting would temporarily stop
338 working while zic was installing a replacement file or link.
340 zic -L no longer omits the POSIX TZ string in its output.
341 Starting with 2020a, zic -L truncated its output according to the
342 "Expires" directive or "#expires" comment in the leapseconds file.
343 The resulting TZif files omitted daylight saving transitions after
344 the leap second table expired, which led to far less-accurate
345 predictions of times after the expiry. Although future timestamps
346 cannot be converted accurately in the presence of leap seconds, it
347 is more accurate to convert near-future timestamps with a few
348 seconds error than with an hour error, so zic -L no longer
349 truncates output in this way.
351 Instead, when zic -L is given the "Expires" directive, it now
352 outputs the expiration by appending a no-change entry to the leap
353 second table. Although this should work well with most TZif
354 readers, it does not conform to Internet RFC 8536 and some pickier
355 clients (including tzdb 2017c through 2021a) reject it, so
356 "Expires" directives are currently disabled by default. To enable
357 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
358 this new feature it is marked with a new TZif version number 4,
359 a format intended to be documented in a successor to RFC 8536.
361 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
362 that omits leap second information for the range LO..B when LO
363 falls between two leap seconds A and B. Instead, it generates a
364 TZif version 4 file that represents the previously-missing
367 The TZif reader now allows the leap second table to begin with a
368 correction other than -1 or +1, and to contain adjacent
369 transitions with equal corrections. This supports TZif version 4.
371 The TZif reader now lets leap seconds occur less than 28 days
372 apart. This supports possible future TZif extensions.
374 Fix bug that caused 'localtime' etc. to crash when TZ was
375 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
376 not conform to POSIX but does conform to Internet RFC 8536.
378 Fix another bug that caused 'localtime' etc. to crash when TZ was
379 set to a POSIX-conforming but unusual TZ string like
380 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
382 Fix yet another bug that caused 'localtime' etc. to mishandle slim
383 TZif files containing leap seconds after the last explicit
384 transition in the table, or when handling far-future timestamps
385 in slim TZif files lacking leap seconds.
387 Fix localtime misbehavior involving positive leap seconds.
388 This change affects only behavior for "right" system time,
389 which contains leap seconds, and only if the UT offset is
390 not a multiple of 60 seconds when a positive leap second occurs.
391 (No such timezone exists in tzdb, luckily.) Without the fix,
392 the timestamp was ambiguous during a positive leap second.
393 With the fix, any seconds occurring after a positive leap second
394 and within the same localtime minute are counted through 60, not
395 through 59; their UT offset (tm_gmtoff) is the same as before.
396 Here is how the fix affects timestamps in a timezone with UT
397 offset +01:23:45 (5025 seconds) and with a positive leap second at
398 1972-06-30 23:59:60 UTC (78796800):
400 time_t without the fix with the fix
401 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
402 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
404 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
405 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
407 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
408 civil time changes a few seconds before time_t wraps around, when
409 leap seconds are enabled.
411 Fix bug in zic -r; in some cases, the dummy time type after the
412 last time transition disagreed with the TZ string, contrary to
413 Internet RFC 8563 section 3.3.
415 Fix a bug with 'zic -r @X' when X is a negative leap second that
416 has a nonnegative correction. Without the fix, the output file
417 was truncated so that X appeared to be a positive leap second.
418 Fix a similar, even-less-likely bug when truncating at a positive
419 leap second that has a nonpositive correction.
421 zic -r now reports an error if given rolling leap seconds, as this
422 usage has never generally worked and is evidently unused.
424 zic now generates a POSIX-conforming TZ string for TZif files
425 where all-year DST is predicted for the indefinite future.
426 For example, for all-year Eastern Daylight Time, zic now generates
427 "XXX3EDT4,0/0,J365/23" where it previously generated
428 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
429 noting the possibility of POSIX conformance.)
431 zic.c no longer requires sys/wait.h (thanks to spazmodius for
432 noting it wasn't needed).
434 When reading slim TZif files, zdump no longer mishandles leap
435 seconds on the rare platforms where time_t counts leap seconds,
436 fixing a bug introduced in 2014g.
438 zdump -v now outputs timestamps at boundaries of what localtime
439 and gmtime can represent, instead of the less-useful timestamps
440 one day after the minimum and one day before the maximum.
441 (Thanks to Arthur David Olson for prototype code, and to Manuela
442 Friedrich for debugging help.)
444 zdump's -c and -t options are now consistently inclusive for the
445 lower time bound and exclusive for the upper. Formerly they were
446 inconsistent. (Confusion noted by Martin Burnicki.)
448 Changes to build procedure
450 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
451 non-POSIX hosts where malloc doesn't set errno.
452 (Problem reported by Jan Engelhardt.)
454 Changes to documentation
456 tzfile.5 better matches a draft successor to RFC 8536
457 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
460 Release 2021a - 2021-01-24 10:54:57 -0800
462 Changes to future timestamps
464 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
465 (Thanks to Steffen Thorsen.)
468 Release 2020f - 2020-12-29 00:17:46 -0800
470 Change to build procedure
472 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
473 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
476 Release 2020e - 2020-12-22 15:14:34 -0800
479 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
481 Changes to future timestamps
483 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
484 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
486 Changes to past timestamps
488 Correct many pre-1986 transitions, fixing entries originally
489 derived from Shanks. The fixes include:
490 - Australia: several 1917 through 1971 transitions
491 - The Bahamas: several 1941 through 1945 transitions
492 - Bermuda: several 1917 through 1956 transitions
493 - Belize: several 1942 through 1968 transitions
494 - Ghana: several 1915 through 1956 transitions
495 - Israel and Palestine: several 1940 through 1985 transitions
496 - Kenya and adjacent: several 1908 through 1960 transitions
497 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
498 through 1919 transitions
499 - Seychelles: the introduction of standard time in 1907, not 1906
500 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
503 Because of the Australia change, Australia/Currie (King Island) is
504 no longer needed, as it is identical to Australia/Hobart for all
505 timestamps since 1970 and was therefore created by mistake.
506 Australia/Currie has been moved to the 'backward' file and its
507 corrected data moved to the 'backzone' file.
509 Changes to past time zone abbreviations and DST flags
511 To better match legislation in Turks and Caicos, the 2015 shift to
512 year-round observance of -04 is now modeled as AST throughout before
513 returning to Eastern Time with US DST in 2018, rather than as
514 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
516 Changes to documentation
518 The zic man page now documents zic's coalescing of transitions
519 when a zone falls back just before DST springs forward.
522 Release 2020d - 2020-10-21 11:24:13 -0700
525 Palestine ends DST earlier than predicted, on 2020-10-24.
527 Changes to past and future timestamps
529 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
530 as previously predicted (thanks to Sharef Mustafa.) Its
531 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
532 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
533 its spring 2020 transition was on March 28 at 00:00, not March 27
534 (thanks to Pierre Cashon.) This affects Asia/Gaza and
535 Asia/Hebron. Assume future spring and fall transitions will be on
536 the Saturday preceding the last Sunday of March and October,
540 Release 2020c - 2020-10-16 11:15:53 -0700
543 Fiji starts DST later than usual, on 2020-12-20.
545 Changes to future timestamps
547 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
548 previously predicted. DST will still end on 2021-01-17.
549 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
550 the later-than-usual start date is a one-time departure from the
553 Changes to build procedure
555 Rearguard tarballs now contain an empty file pacificnew.
556 Some older downstream software expects this file to exist.
557 (Problem reported by Mike Cullinan.)
560 Release 2020b - 2020-10-06 18:35:04 -0700
563 Revised predictions for Morocco's changes starting in 2023.
564 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
565 Macquarie Island has stayed in sync with Tasmania since 2011.
566 Casey, Antarctica is at +08 in winter and +11 in summer.
567 zic no longer supports -y, nor the TYPE field of Rules.
569 Changes to future timestamps
571 Morocco's spring-forward after Ramadan is now predicted to occur
572 no sooner than two days after Ramadan, instead of one day.
573 (Thanks to Milamber.) The first altered prediction is for 2023,
574 now predicted to spring-forward on April 30 instead of April 23.
576 Changes to past and future timestamps
578 Casey Station, Antarctica has been using +08 in winter and +11 in
579 summer since 2018. The most recent transition from +08 to +11 was
580 2020-10-04 00:01. Also, Macquarie Island has been staying in
581 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
583 Changes to past and future time zone abbreviations and DST flags
585 Canada's Yukon, represented by America/Whitehorse and
586 America/Dawson, changes its time zone rules from -08/-07 to
587 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
588 This change affects only the time zone abbreviation (MST vs PDT)
589 and daylight saving flag for the period between the two dates.
590 (Thanks to Andrew G. Smith.)
592 Changes to past timestamps
594 Correct several transitions for Hungary for 1918/1983.
595 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
596 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
597 time was on 11-01, not 10-01 (thanks to Michael Deckers).
599 The 1891 French transition was on March 16, not March 15. The
600 1911-03-11 French transition was at midnight, not a minute later.
601 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
602 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
606 Support for zic's long-obsolete '-y YEARISTYPE' option has been
607 removed and, with it, so has support for the TYPE field in Rule
608 lines, which is now reserved for compatibility with earlier zic.
609 These features were previously deprecated in release 2015f.
610 (Thanks to Tim Parenti.)
612 zic now defaults to '-b slim' instead of to '-b fat'.
614 zic's new '-l -' and '-p -' options uninstall any existing
615 localtime and posixrules files, respectively.
617 The undocumented and ineffective tzsetwall function has been
620 Changes to build procedure
622 The Makefile now defaults POSIXRULES to '-', so the posixrules
623 feature (obsolete as of 2019b) is no longer installed by default.
625 Changes to documentation and commentary
627 The long-obsolete files pacificnew, systemv, and yearistype.sh have
628 been removed from the distribution. (Thanks to Tim Parenti.)
631 Release 2020a - 2020-04-23 16:03:47 -0700
634 Morocco springs forward on 2020-05-31, not 2020-05-24.
635 Canada's Yukon advanced to -07 year-round on 2020-03-08.
636 America/Nuuk renamed from America/Godthab.
637 zic now supports expiration dates for leap second lists.
639 Changes to future timestamps
641 Morocco's second spring-forward transition in 2020 will be May 31,
642 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
643 Adjust future-year predictions to use the first Sunday after the
644 day after Ramadan, not the first Sunday after Ramadan.
646 Canada's Yukon, represented by America/Whitehorse and
647 America/Dawson, advanced to -07 year-round, beginning with its
648 spring-forward transition on 2020-03-08, and will not fall back on
649 2020-11-01. Although a government press release calls this
650 "permanent Pacific Daylight Saving Time", we prefer MST for
651 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
652 (Thanks to Tim Parenti.)
654 Changes to past timestamps
656 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
658 Changes to timezone identifiers
660 To reflect current usage in English better, America/Godthab has
661 been renamed to America/Nuuk. A backwards-compatibility link
662 remains for the old name.
666 localtime.c no longer mishandles timestamps after the last
667 transition in a TZif file with leap seconds and with daylight
668 saving time transitions projected into the indefinite future.
669 For example, with TZ='America/Los_Angeles' with leap seconds,
670 zdump formerly reported a DST transition on 2038-03-14
671 from 01:59:32.999... to 02:59:33 instead of the correct transition
672 from 01:59:59.999... to 03:00:00.
674 zic -L now supports an Expires line in the leapseconds file, and
675 truncates the TZif output accordingly. This propagates leap
676 second expiration information into the TZif file, and avoids the
677 abovementioned localtime.c bug as well as similar bugs present in
678 many client implementations. If no Expires line is present, zic
679 -L instead truncates the TZif output based on the #expires comment
680 present in leapseconds files distributed by tzdb 2018f and later;
681 however, this usage is obsolescent. For now, the distributed
682 leapseconds file has an Expires line that is commented out, so
683 that the file can be fed to older versions of zic which ignore the
684 commented-out line. Future tzdb distributions are planned to
685 contain a leapseconds file with an Expires line.
687 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
688 set to 1 if the system library supports the feature, and 2 if not.
689 As before, these macros are nonzero if tzcode should support the
690 feature, zero otherwise.
692 The configuration macro ALTZONE now has the same values with the
693 same meaning as HAVE_TZNAME and USG_COMPAT.
695 The code's defense against CRLF in leap-seconds.list is now
696 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
698 Although the undocumented tzsetwall function is not changed in
699 this release, it is now deprecated in preparation for removal in
700 future releases. Due to POSIX requirements, tzsetwall has not
701 worked for some time. Any code that uses it should instead use
702 tzalloc(NULL) or, if portability trumps thread-safety, should
703 unset the TZ environment variable.
705 Changes to commentary
707 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
708 following America/Halifax, and comments about Yukon's "south" and
709 "north" have been corrected to say "east" and "west". (Thanks to
713 Release 2019c - 2019-09-11 08:59:48 -0700
716 Fiji observes DST from 2019-11-10 to 2020-01-12.
717 Norfolk Island starts observing Australian-style DST.
719 Changes to future timestamps
721 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
722 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
723 Adjust future guesses accordingly.
725 Norfolk Island will observe Australian-style DST starting in
726 spring 2019. The first transition is on 2019-10-06. (Thanks to
727 Kyle Czech and Michael Deckers.)
729 Changes to past timestamps
731 Many corrections to time in Turkey from 1940 through 1985.
732 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
734 The Norfolk Island 1975-03-02 transition was at 02:00 standard
735 time, not 02:00 DST. (Thanks to Michael Deckers.)
737 South Korea observed DST from 1948 through 1951. Although this
738 info was supposed to appear in release 2014j, a typo inadvertently
739 suppressed the change. (Thanks to Alois Treindl.)
741 Detroit observed DST in 1967 and 1968 following the US DST rules,
742 except that its 1967 DST began on June 14 at 00:01. (Thanks to
743 Alois Treindl for pointing out that the old data entries were
746 Fix several errors in pre-1970 transitions in Perry County, IN.
747 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
749 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
750 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
751 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
752 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
753 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
754 Königsberg switched to +03 on 04-07 not 01-01.
756 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
757 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
758 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
760 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
761 (Thanks to Michael Deckers.)
763 Changes to past time zone abbreviations and DST flags
765 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
766 is now flagged as DST and is abbreviated HKWT not HKT.
770 leapseconds.awk now relies only on its input data, rather than
771 also relying on its comments. (Inspired by code from Dennis
772 Ferguson and Chris Woodbury.)
774 The code now defends against CRLFs in leap-seconds.list.
775 (Thanks to Brian Inglis and Chris Woodbury.)
777 Changes to documentation and commentary
779 theory.html discusses leap seconds. (Thanks to Steve Summit.)
781 Nashville's newspapers dueled about the time of day in the 1950s.
782 (Thanks to John Seigenthaler.)
784 Liechtenstein observed Swiss DST in 1941/2.
785 (Thanks to Alois Treindl.)
788 Release 2019b - 2019-07-01 00:09:53 -0700
791 Brazil no longer observes DST.
792 'zic -b slim' outputs smaller TZif files; please try it out.
793 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
795 Changes to future timestamps
797 Brazil has canceled DST and will stay on standard time indefinitely.
798 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
801 Predictions for Morocco now go through 2087 instead of 2037, to
802 work around a problem on newlib when using TZif files output by
803 zic 2019a or earlier. (Problem reported by David Gauchard.)
805 Changes to past and future timestamps
807 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
808 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
809 future transitions to be March's last Friday at 00:00.
811 Changes to past timestamps
813 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
814 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
815 not 09-15 at 00:00. In 1946 its spring-forward transition was on
816 04-21 at 00:00, not the previous day at 03:30. From 1946 through
817 1952 its fall-back transitions occurred at 04:30, not at 03:30.
818 In 1947 its fall-back transition was on 11-30, not 12-30.
821 Changes to past time zone abbreviations
823 Italy's 1866 transition to Rome Mean Time was on December 12, not
824 September 22. This affects only the time zone abbreviation for
825 Europe/Rome between those dates. (Thanks to Stephen Trainor and
828 Changes affecting metadata only
830 Add info about the Crimea situation in zone1970.tab and zone.tab.
831 (Problem reported by Serhii Demediuk.)
835 zic's new -b option supports a way to control data bloat and to
836 test for year-2038 bugs in software that reads TZif files.
837 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
838 for example, changing from fat to slim shrinks the Europe/London
839 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
840 files represent the same set of timestamps and use the same TZif
841 format as documented in tzfile(5) and in Internet RFC 8536.
842 Fat format attempts to work around bugs or incompatibilities in
843 older software, notably software that mishandles 64-bit TZif data
844 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
845 Slim format is more efficient and does not work around 64-bit bugs
846 or obsolete TZ strings. Currently zic defaults to fat format
847 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
848 out-of-the-box default is intended to change in future releases
849 as the buggy software often mishandles timestamps anyway.
851 zic no longer treats a set of rules ending in 2037 specially.
852 Previously, zic assumed that such a ruleset meant that future
853 timestamps could not be predicted, and therefore omitted a
854 POSIX-like TZ string in the TZif output. The old behavior is no
855 longer needed for current tzdata, and caused problems with newlib
856 when used with older tzdata (reported by David Gauchard).
858 zic no longer generates some artifact transitions. For example,
859 Europe/London no longer has a no-op transition in January 1996.
861 Changes to build procedure
863 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
866 Changes to documentation and commentary
868 The Makefile now documents the POSIXRULES macro as being obsolete,
869 and similarly, zic's -p POSIXRULES option is now documented as
870 being obsolete. Although the POSIXRULES feature still exists and
871 works as before, in practice it is rarely used for its intended
872 purpose, and it does not work either in the default reference
873 implementation (for timestamps after 2037) or in common
874 implementations such as GNU/Linux (for contemporary timestamps).
875 Since POSIXRULES was designed primarily as a temporary transition
876 facility for System V platforms that died off decades ago, it is
877 being decommissioned rather than institutionalized.
879 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
882 Release 2019a - 2019-03-25 22:01:33 -0700
885 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
886 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
888 Changes to past and future timestamps
890 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
891 previously predicted. Adjust our prediction by guessing that spring
892 transitions will be between 24 and 30 March, which matches recent practice
893 since 2016. (Thanks to Even Scharning and Tim Parenti.)
895 Metlakatla ended its observance of Pacific standard time,
896 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
897 Stanley and Tim Parenti.)
899 Changes to past timestamps
901 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
902 (Thanks to Alois Treindl and Isaac Starkman.)
904 Changes to time zone abbreviations
906 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
907 of being a separate zone that generates the abbreviation "UCT",
908 which nowadays is typically a typo. (Problem reported by Isiah
913 zic now has an -r option to limit the time range of output data.
914 For example, 'zic -r @1000000000' limits the output data to
915 timestamps starting 1000000000 seconds after the Epoch.
916 This helps shrink output size and can be useful for applications
917 not needing the full timestamp history, such as TZDIST truncation;
918 see Internet RFC 8536 section 5.1. (Inspired by a feature request
919 from Christopher Wong, helped along by bug reports from Wong and
922 Changes to documentation
924 Mention Internet RFC 8536 (February 2019), which documents TZif.
926 tz-link.html now cites tzdata-meta
927 <https://tzdata-meta.timtimeonline.com/>.
930 Release 2018i - 2018-12-30 11:05:43 -0800
933 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
935 Changes to future timestamps
937 Due to a change in government, São Tomé and Príncipe switches back
938 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
939 Nasardinov and Michael Deckers.)
942 Release 2018h - 2018-12-23 17:59:32 -0800
945 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
946 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
947 Metlakatla, Alaska observes PST this winter only.
948 Guess Morocco will continue to adjust clocks around Ramadan.
949 Add predictions for Iran from 2038 through 2090.
951 Changes to future timestamps
953 Guess that Morocco will continue to fall back just before and
954 spring forward just after Ramadan, the practice since 2012.
955 (Thanks to Maamar Abdelkader.) This means Morocco will observe
956 negative DST during Ramadan in main and vanguard formats, and in
957 rearguard format it stays in the +00 timezone and observes
958 ordinary DST in all months other than Ramadan. As before, extend
959 this guesswork to the year 2037. As a consequence, Morocco is
960 scheduled to observe three DST transitions in some Gregorian years
961 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
964 The table of exact transitions for Iranian DST has been extended.
965 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
966 It now cuts off before 2091 as there is doubt about how the Persian
967 calendar will treat 2091. This change predicts DST transitions in
968 2038-9, 2042-3, and 2046-7 to occur one day later than previously
969 predicted. As before, post-cutoff transitions are approximated.
971 Changes to past and future timestamps
973 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
974 +05 on 2018-12-21. This is a zone split as Qostanay (aka
975 Kostanay) did not switch, so create a zone Asia/Qostanay.
977 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
978 It did not change clocks that day and remains on -08 this winter.
979 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
980 rules next spring, so this change affects only timestamps
981 from 2018-11-04 through 2019-03-10.
983 Change to past timestamps
985 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
986 not 00:00. I transcribed the time incorrectly from Shanks.
987 (Thanks to Phake Nick.)
989 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
990 (Thanks to Phake Nick.)
992 Guam observed DST irregularly from 1959 through 1977.
993 (Thanks to Phake Nick.)
995 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
996 10-01 changed standard time to +08:30 (not +08). Its transition
997 back to +08 after WWII was on 1945-09-15, not the previous day.
998 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
999 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1000 its 1952 fallback was on 11-02 (not 10-25).
1002 This release contains many changes to timestamps before 1946 due
1003 to Japanese possession or occupation of Pacific/Chuuk,
1004 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1005 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1006 (Thanks to Phake Nick.)
1008 Assume that the Spanish East Indies was like the Philippines and
1009 observed American time until the end of 1844. This affects
1010 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1012 Changes to past tm_isdst flags
1014 For the recent Morocco change, the tm_isdst flag should be 1 from
1015 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1016 Give a URL to the official decree. (Thanks to Matt Johnson.)
1019 Release 2018g - 2018-10-26 22:22:45 -0700
1022 Morocco switches to permanent +01 on 2018-10-28.
1024 Changes to future timestamps
1026 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1027 so its clocks will not fall back as previously scheduled.
1028 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1032 When generating TZif files with leap seconds, zic no longer uses a
1033 format that trips up older 32-bit clients, fixing a bug introduced
1034 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1035 for QTBUG-53071 now also works for TZif files with leap seconds.
1037 The translator to rearguard format now rewrites the line
1038 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1039 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1040 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1041 and earlier. (Reported by Christos Zoulas.)
1043 Changes to past time zone abbreviations
1045 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1046 This reverts to 2011h, as the abbreviation change in 2011i was
1049 Changes to documentation
1051 tzfile.5 has new sections on interoperability issues.
1054 Release 2018f - 2018-10-18 00:14:18 -0700
1057 Volgograd moves from +03 to +04 on 2018-10-28.
1058 Fiji ends DST 2019-01-13, not 2019-01-20.
1059 Most of Chile changes DST dates, effective 2019-04-06.
1061 Changes to future timestamps
1063 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1064 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1066 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1067 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1070 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1071 time, and resume DST on the first Saturday in September at 24:00 mainland
1072 time. The changes are effective from 2019-04-06, and do not affect the
1073 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1074 and Tim Parenti.) Adjust future predictions accordingly.
1076 Changes to past timestamps
1078 The 2018-05-05 North Korea 30-minute time zone change took place
1079 at 23:30 the previous day, not at 00:00 that day.
1081 China's 1988 spring-forward transition was on April 17, not
1082 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1085 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1086 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1087 temporarily switched to +09/+10 during World War II. Macau
1088 observed DST in 1942/79, not 1961/80, and there were several
1089 errors for transition times and dates. (Thanks to P Chan.)
1091 The 1948-1951 fallback transitions in Japan were at 25:00 on
1092 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1093 zic turns this into 01:00 on the day after September's second
1094 Saturday, which is the best that POSIX or C platforms can do.
1096 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1097 paper by Li Yu, replacing more-questionable data from Shanks.
1099 Changes to time zone abbreviations
1101 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1105 zic now always generates TZif files where time type 0 is used for
1106 timestamps before the first transition. This simplifies the
1107 reading of TZif files and should not affect behavior of existing
1108 TZif readers because the same set of time types is used; only
1109 their internal indexes may have changed. This affects only the
1110 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1111 EET, which previously used nonzero types for these timestamps.
1113 Because of the type 0 change, zic no longer outputs a dummy
1114 transition at time -2**59 (before the Big Bang), as clients should
1115 no longer need this to handle historical timestamps correctly.
1116 This reverts a change introduced in 2013d and shrinks most TZif
1117 files by a few bytes.
1119 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1120 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1121 occurs at 18:00 on the Saturday before the last Sunday in April.
1122 This behavior was documented in 2018a but the code did not
1123 entirely match the documentation.
1125 localtime.c no longer requires at least one time type in TZif
1126 files that lack transitions or have a POSIX-style TZ string. This
1127 future-proofs the code against possible future extensions to the
1128 format that would allow TZif files with POSIX-style TZ strings and
1129 without transitions or time types.
1131 A read-access subscript error in localtime.c has been fixed.
1132 It could occur only in TZif files with timecnt == 0, something that
1133 does not happen in practice now but could happen in future versions.
1135 localtime.c no longer ignores TZif POSIX-style TZ strings that
1136 specify only standard time. Instead, these TZ strings now
1137 override the default time type for timestamps after the last
1138 transition (or for all timestamps if there are no transitions),
1139 just as DST strings specifying DST have always done.
1141 leapseconds.awk now outputs "#updated" and "#expires" comments,
1142 and supports leap seconds at the ends of months other than June
1143 and December. (Inspired by suggestions from Chris Woodbury.)
1145 Changes to documentation
1147 New restrictions: A Rule name must start with a character that
1148 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1149 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1150 The latter restriction makes room for future extensions (a
1151 possibility noted by Tom Lane).
1153 tzfile.5 now documents what time types apply before the first and
1154 after the last transition, if any.
1156 Documentation now uses the spelling "timezone" for a TZ setting
1157 that determines timestamp history, and "time zone" for a
1158 geographic region currently sharing the same standard time.
1160 The name "TZif" is now used for the tz binary data format.
1162 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1163 (Thanks to Aldrin Martoq for the link.)
1165 Changes to build procedure
1167 New 'make' target 'rearguard_tarballs' to build the rearguard
1168 tarball only. This is a convenience on platforms that lack lzip
1169 if you want to build the rearguard tarball. (Problem reported by
1172 tzdata.zi is now more stable from release to release. (Problem
1173 noted by Tom Lane.) It is also a bit shorter.
1175 tzdata.zi now can contain comment lines documenting configuration
1176 information, such as which data format was selected, which input
1177 files were used, and how leap seconds are treated. (Problems
1178 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1179 are used these comment lines are absent, for backward
1180 compatibility. A redistributor intending to alter its copy of the
1181 files should also append "-LABEL" to the 'version' file's first
1182 line, where "LABEL" identifies the redistributor's change.
1185 Release 2018e - 2018-05-01 23:42:51 -0700
1189 North Korea switches back to +09 on 2018-05-05.
1190 The main format uses negative DST again, for Ireland etc.
1191 'make tarballs' now also builds a rearguard tarball.
1192 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1194 Changes to past and future timestamps
1196 North Korea switches back from +0830 to +09 on 2018-05-05.
1197 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1200 Bring back the negative-DST changes of 2018a, except be more
1201 compatible with data parsers that do not support negative DST.
1202 Also, this now affects historical timestamps in Namibia and the
1203 former Czechoslovakia, not just Ireland. The main format now uses
1204 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1205 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1206 does not affect UT offsets, only time zone abbreviations and the
1207 tm_isdst flag. Also, this does not affect rearguard or vanguard
1208 formats; effectively the main format now uses vanguard instead of
1209 rearguard format. Data parsers that do not support negative DST
1210 can still use data from the rearguard tarball described below.
1212 Changes to build procedure
1214 The command 'make tarballs' now also builds the tarball
1215 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1216 except that it uses rearguard format intended for trailing-edge
1219 Changes to data format and to code
1221 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1222 suffix, which specifies whether the adjusted time is standard time
1223 or daylight saving time. If no suffix is given, daylight saving
1224 time is used if and only if the SAVE column is nonzero; this is
1225 the longstanding behavior. Although this new feature is not used
1226 in tzdata, it could be used to specify the legal time in Namibia
1227 1994-2017, as opposed to the popular time (see below).
1229 Changes to past timestamps
1231 From 1994 through 2017 Namibia observed DST in winter, not summer.
1232 That is, it used negative DST, as Ireland still does. This change
1233 does not affect UTC offsets; it affects only the tm_isdst flag and
1234 the abbreviation used during summer, which is now CAT, not WAST.
1235 Although (as noted by Michael Deckers) summer and winter time were
1236 both simply called "standard time" in Namibian law, in common
1237 practice winter time was considered to be DST (as noted by Stephen
1238 Colebourne). The full effect of this change is only in vanguard
1239 and main format; in rearguard format, the tm_isdst flag is still
1240 zero in winter and nonzero in summer.
1242 In 1946/7 Czechoslovakia also observed negative DST in winter.
1243 The full effect of this change is only in vanguard and main
1244 formats; in rearguard format, it is modeled as plain GMT without
1245 daylight saving. Also, the dates of some 1944/5 DST transitions
1246 in Czechoslovakia have been changed.
1249 Release 2018d - 2018-03-22 07:05:46 -0700
1253 Palestine starts DST a week earlier in 2018.
1254 Add support for vanguard and rearguard data consumers.
1255 Add subsecond precision to source data format, though not to data.
1257 Changes to future timestamps
1259 In 2018, Palestine starts DST on March 24, not March 31.
1260 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1262 Changes to past and future timestamps
1264 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1265 at 04:00. (Thanks to Steffen Thorsen.)
1267 Changes to past timestamps
1269 Historical transitions for Uruguay, represented by
1270 America/Montevideo, have been updated per official legal documents,
1271 replacing previous data mainly originating from the inventions of
1272 Shanks & Pottenger. This has resulted in adjustments ranging from
1273 30 to 90 minutes in either direction over at least two dozen
1274 distinct periods ranging from one day to several years in length.
1275 A mere handful of pre-1991 transitions are unaffected; data since
1276 then has come from more reliable contemporaneous reporting. These
1277 changes affect various timestamps in 1920-1923, 1936, 1939,
1278 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1279 Additionally, Uruguay's pre-standard-time UT offset has been
1280 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1281 match the location of the Observatory of the National Meteorological
1282 Institute in Montevideo.
1283 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1285 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1286 (Thanks to Kerry Shetline.)
1288 Fix the 1912-01-01 transition for Portugal and its colonies.
1289 This transition was at 00:00 according to the new UT offset, not
1290 according to the old one. Also assume that Cape Verde switched on
1291 the same date as the rest, not in 1907. This affects
1292 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1293 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1294 (Thanks to Michael Deckers.)
1296 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1299 Changes to past time zone abbreviations
1301 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1302 is no clock change associated with the transition.
1304 Changes to build procedure
1306 The new DATAFORM macro in the Makefile lets the installer choose
1307 among three source data formats. The idea is to lessen downstream
1308 disruption when data formats are improved.
1310 * DATAFORM=vanguard installs from the latest, bleeding-edge
1311 format. DATAFORM=main (the default) installs from the format
1312 used in the 'africa' etc. files. DATAFORM=rearguard installs
1313 from a trailing-edge format. Eventually, elements of today's
1314 vanguard format should move to the main format, and similarly
1315 the main format's features should eventually move to the
1318 * In the current version, the main and rearguard formats are
1319 identical and match that of 2018c, so this change does not
1320 affect default behavior. The vanguard format currently contains
1321 one feature not in the main format: negative SAVE values. This
1322 improves support for Ireland, which uses Irish Standard Time
1323 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1324 supported negative SAVE values for decades, and this feature
1325 should move to the main format soon. However, it will not move
1326 to the rearguard format for quite some time because some
1327 downstream parsers do not support it.
1329 * The build procedure constructs three files vanguard.zi, main.zi,
1330 and rearguard.zi, one for each format. Although the files
1331 represent essentially the same data, they may have minor
1332 discrepancies that users are not likely to notice. The files
1333 are intended for downstream data consumers and are not
1334 installed. Zoneinfo parsers that do not support negative SAVE values
1335 should start using rearguard.zi, so that they will be unaffected
1336 when the negative-DST feature moves from vanguard to main.
1337 Bleeding-edge Zoneinfo parsers that support the new features
1338 already can use vanguard.zi; in this respect, current tzcode is
1341 The Makefile should now be safe for parallelized builds, and 'make
1342 -j to2050new.tzs' is now much faster on a multiprocessor host
1345 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1346 prepends TZDIR/ to file names that do not begin with '/'. This is
1347 not recommended for general use, due to its security implications.
1348 (From a suggestion by Manuela Friedrich.)
1352 zic now accepts subsecond precision in expressions like
1353 00:19:32.13, which is approximately the legal time of the
1354 Netherlands from 1835 to 1937. However, because it is
1355 questionable whether the few recorded uses of non-integer offsets
1356 had subsecond precision in practice, there are no plans for tzdata
1357 to use this feature. (Thanks to Steve Allen for pointing out
1358 the limitations of historical data in this area.)
1360 The code is a bit more portable to MS-Windows. Installers can
1361 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1362 reserve identifiers like 'localtime'. (Thanks to Manuela
1365 Changes to documentation and commentary
1367 theory.html now outlines tzdb's extensions to POSIX's model for
1368 civil time, and has a section "POSIX features no longer needed"
1369 that lists POSIX API components that are now vestigial.
1370 (From suggestions by Steve Summit.) It also better distinguishes
1371 time zones from tz regions. (From a suggestion by Guy Harris.)
1373 Commentary is now more consistent about using the phrase "daylight
1374 saving time", to match the C name tm_isdst. Daylight saving time
1375 need not occur in summer, and need not have a positive offset from
1378 Commentary about historical transitions in Uruguay has been expanded
1379 with links to many relevant legal documents.
1380 (Thanks to Tim Parenti.)
1382 Commentary now uses some non-ASCII characters with Unicode value
1383 less than U+0100, as they can be useful and should work even with
1384 older editors such as XEmacs.
1387 Release 2018c - 2018-01-22 23:00:44 -0800
1390 Revert Irish changes that relied on negative SAVE values.
1394 Revert the 2018a change to Europe/Dublin. As before, this change
1395 does not affect UT offsets or abbreviations; it affects only
1396 whether timestamps are considered to be standard time or
1397 daylight-saving time, as expressed in the tm_isdst flag of C's
1398 struct tm type. This reversion is intended to be a temporary
1399 workaround for problems discovered with downstream uses of
1400 releases 2018a and 2018b, which implemented Irish time by using
1401 negative SAVE values in the Eire rules of the 'europe' file.
1402 Although negative SAVE values have been part of tzcode for many
1403 years and are supported by many platforms, they were not
1404 documented before 2018a and ICU and OpenJDK do not currently
1405 support them. A mechanism to export data to platforms lacking
1406 support for negative DST is planned to be developed before the
1407 change is reapplied. (Problems reported by Deborah Goldsmith and
1408 Stephen Colebourne.)
1410 Changes to past timestamps
1412 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1413 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1415 Changes to build procedure
1417 The build procedure now works around mawk 1.3.3's lack of support
1418 for character class expressions. (Problem reported by Ohyama.)
1421 Release 2018b - 2018-01-17 23:24:48 -0800
1424 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1426 Changes to build procedure
1428 The distribution now contains the file 'pacificnew' again.
1429 This file was inadvertently omitted in the 2018a distribution.
1430 (Problem reported by Matias Fonzo.)
1433 Release 2018a - 2018-01-12 22:29:21 -0800
1436 São Tomé and Príncipe switched from +00 to +01.
1437 Brazil's DST will now start on November's first Sunday.
1438 Ireland's standard time is now in the summer, not the winter.
1439 Use Debian-style installation locations, instead of 4.3BSD-style.
1442 Changes to past and future timestamps
1444 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1445 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1447 Changes to future timestamps
1449 Starting in 2018 southern Brazil will begin DST on November's
1450 first Sunday instead of October's third Sunday. (Thanks to
1453 Changes to past timestamps
1455 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1456 been corrected. The 'backzone' and 'zone.tab' files did not agree
1457 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1460 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1461 BST instead of BOST, to be more consistent with the convention
1462 used for Latvian Summer Time (1918-9) and for British Summer Time.
1466 Change Europe/Dublin so that it observes Irish Standard Time (UT
1467 +01) in summer and GMT (as negative daylight-saving) in winter,
1468 instead of observing standard time (GMT) in winter and Irish
1469 Summer Time (UT +01) in summer. This change does not affect UT
1470 offsets or abbreviations; it affects only whether timestamps are
1471 considered to be standard time or daylight-saving time, as
1472 expressed in the tm_isdst flag of C's struct tm type.
1473 (Discrepancy noted by Derick Rethans.)
1475 Changes to build procedure
1477 The default installation locations have been changed to mostly
1478 match Debian circa 2017, instead of being designed as an add-on to
1479 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1480 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1481 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1482 locations more precisely. (This responds to suggestions from
1483 Brian Inglis and from Steve Summit.)
1485 The default installation procedure no longer creates the
1486 backward-compatibility link US/Pacific-New, which causes
1487 confusion during user setup (e.g., see Debian bug 815200).
1488 Use 'make BACKWARD="backward pacificnew"' to create the link
1489 anyway, for now. Eventually we plan to remove the link entirely.
1491 tzdata.zi now contains a version-number comment.
1492 (Suggested by Tom Lane.)
1494 The Makefile now quotes values like BACKWARD more carefully when
1495 passing them to the shell. (Problem reported by Zefram.)
1497 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1498 that have snprintf and use pre-C99 compilers. (Problem reported
1503 zic has a new option -t FILE that specifies the location of the
1504 file that determines local time when TZ is unset. The default for
1505 this location can be configured via the new TZDEFAULT makefile
1506 macro, which defaults to /etc/localtime.
1508 Diagnostics and commentary now distinguish UT from UTC more
1509 carefully; see theory.html for more information about UT vs UTC.
1511 zic has been ported to GCC 8's -Wstringop-truncation option.
1512 (Problem reported by Martin Sebor.)
1514 Changes to documentation and commentary
1516 The zic man page now documents the longstanding behavior that
1517 times and years can be out of the usual range, with negative times
1518 counting backwards from midnight and with year 0 preceding year 1.
1519 (Problem reported by Michael Deckers.)
1521 The theory.html file now mentions the POSIX limit of six chars
1522 per abbreviation, and lists alphabetic abbreviations used.
1524 The files tz-art.htm and tz-link.htm have been renamed to
1525 tz-art.html and tz-link.html, respectively, for consistency with
1526 other file names and to simplify web server configuration.
1529 Release 2017c - 2017-10-20 14:49:34 -0700
1532 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1533 Fiji ends DST 2018-01-14, not 2018-01-21.
1534 Namibia switches from +01/+02 to +02 on 2018-04-01.
1535 Sudan switches from +03 to +02 on 2017-11-01.
1536 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1537 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1538 A new file tzdata.zi now holds a small text copy of all data.
1539 The zic input format has been regularized slightly.
1541 Changes to future timestamps
1543 Northern Cyprus has decided to resume EU rules starting
1544 2017-10-29, thus reinstituting winter time.
1546 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1547 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1550 Namibia will switch from +01 with DST to +02 all year on
1551 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1552 at 02:00. (Thanks to Steffen Thorsen.)
1554 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1555 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1556 Africa/Juba is no longer a link to Africa/Khartoum.
1558 Tonga has likely ended its experiment with DST, and will not
1559 adjust its clocks on 2017-11-05. Although Tonga has not announced
1560 whether it will continue to observe DST, the IATA is assuming that
1561 it will not. (Thanks to David Wade.)
1563 Turks & Caicos will switch from -04 all year to -05 with US DST on
1564 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1565 at 02:00. (Thanks to Steffen Thorsen.)
1567 Changes to past timestamps
1569 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1570 (Thanks to Arthur David Olson.)
1572 Detroit did not observe DST in 1967.
1574 Use railway time for Asia/Kolkata before 1941, by switching to
1575 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1576 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1578 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1579 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1581 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1582 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1584 Adjust the 1867 transition in Alaska to better reflect the
1585 historical record, by changing it to occur on 1867-10-18 at 15:30
1586 Sitka time rather than at the start of 1867-10-17 local time.
1587 Although strictly speaking this is accurate only for Sitka,
1588 the rest of Alaska's blanks need to be filled in somehow.
1590 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1591 (Thanks to Michael Deckers.)
1593 Add 7 s to the UT offset in Asia/Yangon before 1920.
1595 Changes to zone names
1597 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1598 exceeded the 14-character limit and was an unused misnomer anyway.
1600 Changes to build procedure
1602 To support applications that prefer to read time zone data in text
1603 form, two zic input files tzdata.zi and leapseconds are now
1604 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1605 leapseconds tzdata.zi' can reproduce the tzdata binary files
1606 without and with leap seconds, respectively. To prevent these two
1607 new files from being installed, use 'make TZDATA_TEXT=', and to
1608 suppress leap seconds from the tzdata text installation, use 'make
1609 TZDATA_TEXT=tzdata.zi'.
1611 'make BACKWARD=' now suppresses backward-compatibility names
1612 like 'US/Pacific' that are defined in the 'backward' and
1615 'make check' now works on systems that lack a UTF-8 locale,
1616 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1617 the name of a UTF-8 locale, if you have one.
1619 Y2K runtime checks are no longer enabled by default. Add
1620 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1621 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1622 to disable them. (New name suggested by Brian Inglis.)
1624 The build procedure for zdump now works on AIX 7.1.
1625 (Problem reported by Kees Dekker.)
1629 zic and the reference runtime now reject multiple leap seconds
1630 within 28 days of each other, or leap seconds before the Epoch.
1631 As a result, support for double leap seconds, which was
1632 obsolescent and undocumented, has been removed. Double leap
1633 seconds were an error in the C89 standard; they have never existed
1634 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1635 noticing glitches in the code that uncovered this problem.)
1637 zic now warns about use of the obsolescent and undocumented -y
1638 option, and about use of the obsolescent TYPE field of Rule lines.
1640 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1641 weekdays; formerly it rejected them due to a bug. Conversely, zic
1642 no longer considers non-prefixes to be abbreviations; for example,
1643 it no longer accepts "lF" as an abbreviation for "lastFriday".
1644 Also, zic warns about the undocumented usage with a "last-"
1645 prefix, e.g., "last-Fri".
1647 Similarly, zic now accepts the unambiguous abbreviation "L" for
1648 "Link" in ordinary context and for "Leap" in leap-second context.
1649 Conversely, zic no longer accepts non-prefixes such as "La" as
1650 abbreviations for words like "Leap".
1652 zic no longer accepts leap second lines in ordinary input, or
1653 ordinary lines in leap second input. Formerly, zic sometimes
1654 warned about this undocumented usage and handled it incorrectly.
1656 The new macro HAVE_TZNAME governs whether the tzname external
1657 variable is exported, instead of USG_COMPAT. USG_COMPAT now
1658 governs only the external variables "timezone" and "daylight".
1659 This change is needed because the three variables are not in the
1660 same category: although POSIX requires tzname, it specifies the
1661 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
1662 if not defined, the code attempts to guess it from other macros.
1664 localtime.c and difftime.c no longer require stdio.h, and .c files
1665 other than zic.c no longer require sys/wait.h.
1667 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
1669 Calculation of time_t extrema works around a bug in GCC 4.8.4
1670 (Reported by Stan Shebs and Joseph Myers.)
1672 zic.c no longer mistranslates formats of line numbers in non-English
1673 locales. (Problem reported by Benno Schulenberg.)
1675 Several minor changes have been made to the code to make it a
1676 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
1677 Dekker for reporting the problems.)
1679 Changes to documentation and commentary
1681 The two new files 'theory.html' and 'calendars' contain the
1682 contents of the removed file 'Theory'. The goal is to document
1683 tzdb theory more accessibly.
1685 The zic man page now documents abbreviation rules.
1687 tz-link.htm now covers how to apply tzdata changes to clients.
1688 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
1690 The leap-seconds.list URL has been updated to something that is
1691 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
1693 Release 2017b - 2017-03-17 07:30:38 -0700
1695 Briefly: Haiti has resumed DST.
1697 Changes to past and future timestamps
1699 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
1701 Changes to past timestamps
1703 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1705 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1706 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
1710 The reference localtime implementation now falls back on the
1711 current US daylight-saving transition rules rather than the
1712 1987-2006 rules. This fallback occurs only when (1) the TZ
1713 environment variable has a value like "AST4ADT" that asks
1714 for daylight saving time but does not specify the rules, (2) there
1715 is no file by that name, and (3) the TZDEFRULES file cannot be
1716 loaded. (Thanks to Tom Lane.)
1719 Release 2017a - 2017-02-28 00:05:36 -0800
1721 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1724 Changes to future timestamps
1726 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
1728 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1729 Its clocks diverge from America/Santiago starting 2017-05-13 at
1730 23:00, hiving off a new zone America/Punta_Arenas. Although the
1731 Chilean government says this change expires in May 2019, for now
1732 assume it's permanent. (Thanks to Juan Correa and Deborah
1733 Goldsmith.) This also affects Antarctica/Palmer.
1735 Changes to past timestamps
1737 Fix many entries for historical timestamps for Europe/Madrid
1738 before 1979, to agree with tables compiled by Pere Planesas of the
1739 National Astronomical Observatory of Spain. As a side effect,
1740 this changes some timestamps for Africa/Ceuta before 1929, which
1741 are probably guesswork anyway. (Thanks to Steve Allen and
1742 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1743 correcting the 1901 transition.)
1745 Ecuador observed DST from 1992-11-28 to 1993-02-05.
1746 (Thanks to Alois Treindl.)
1748 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1749 (Thanks to Stepan Golosunov.)
1751 Changes to past and future time zone abbreviations
1753 Switch to numeric time zone abbreviations for South America, as
1754 part of the ongoing project of removing invented abbreviations.
1755 This avoids the need to invent an abbreviation for the new Chilean
1756 new zone. Similarly, switch from invented to numeric time zone
1757 abbreviations for Afghanistan, American Samoa, the Azores,
1758 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1759 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1760 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1761 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1762 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1763 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1764 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1765 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1766 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1767 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1768 for half-hour daylight saving time in Belize before 1944 and in
1769 the Dominican Republic before 1975; and for Canary Islands before
1770 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1771 Indian Summer Time before 1942, for Indonesia before around 1964,
1772 for Kenya before 1960, for Liberia before 1973, for Madeira before
1773 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1774 Pakistan before 1971, for Western Sahara before 1977, and for
1775 Zaporozhye in 1880-1924.
1777 For Alaska time from 1900 through 1967, instead of "CAT" use the
1778 abbreviation "AST", the abbreviation commonly used at the time
1779 (Atlantic Standard Time had not been standardized yet). Use "AWT"
1780 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1782 Use "CST" and "CDT" instead of invented abbreviations for Macau
1783 before 1999 and Taiwan before 1938, and use "JST" instead of the
1784 invented abbreviation "JCST" for Japan and Korea before 1938.
1786 Change to database entry category
1788 Move the Pacific/Johnston link from 'australasia' to 'backward',
1789 since Johnston is now uninhabited.
1793 zic no longer mishandles some transitions in January 2038 when it
1794 attempts to work around Qt bug 53071. This fixes a bug affecting
1795 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
1796 now contains a workaround, useful when loading a file generated by
1797 a buggy zic. (Problem and localtime.c fix reported by Bradley
1800 zdump -i now outputs non-hour numeric time zone abbreviations
1801 without a colon, e.g., "+0530" rather than "+05:30". This agrees
1802 with zic %z and with common practice, and simplifies auditing of
1805 zdump is now buildable again with -DUSE_LTZ=0.
1806 (Problem reported by Joseph Myers.)
1808 zdump.c now always includes private.h, to avoid code duplication
1809 with private.h. (Problem reported by Kees Dekker.)
1811 localtime.c no longer mishandles early or late timestamps
1812 when TZ is set to a POSIX-style string that specifies DST.
1813 (Problem reported by Kees Dekker.)
1815 date and strftime now cause %z to generate "-0000" instead of
1816 "+0000" when the UT offset is zero and the time zone abbreviation
1819 Changes to documentation and commentary
1821 The 'Theory' file now better documents choice of historical time
1822 zone abbreviations. (Problems reported by Michael Deckers.)
1824 tz-link.htm now covers leap smearing, which is popular in clouds.
1827 Release 2016j - 2016-11-22 23:17:13 -0800
1829 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1831 Changes to future timestamps
1833 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
1834 This hives off a new zone Europe/Saratov from Europe/Volgograd.
1835 (Thanks to Yuri Konotopov and Stepan Golosunov.)
1837 Changes to past timestamps
1839 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
1840 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1841 1999, not fall 1994. (Thanks to Stepan Golosunov.)
1843 Changes to past time zone abbreviations
1845 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
1846 summer time before 1948. The old use of "EET" was a typo.
1850 zic no longer mishandles file systems that lack hard links, fixing
1851 bugs introduced in 2016g. (Problems reported by Tom Lane.)
1852 Also, when the destination already contains symbolic links, zic
1853 should now work better on systems where the 'link' system call
1854 does not follow symbolic links.
1856 Changes to documentation and commentary
1858 tz-link.htm now documents the relationship between release version
1859 numbers and development-repository commit tags. (Suggested by
1862 The 'Theory' file now documents UT.
1864 iso3166.tab now accents "Curaçao", and commentary now mentions
1865 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
1868 Release 2016i - 2016-11-01 23:19:52 -0700
1870 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
1871 reintroduces DST on 2016-11-06.
1873 Changes to future timestamps
1875 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
1876 2017-01-15 at 03:00. Assume future observances in Tonga will be
1877 from the first Sunday in November through the third Sunday in
1878 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
1879 time zone abbreviations for this zone.
1881 Changes to past and future timestamps
1883 Northern Cyprus is now +03 year round, causing a split in Cyprus
1884 time zones starting 2016-10-30 at 04:00. This creates a zone
1885 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
1887 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
1888 (Thanks to Steffen Thorsen.)
1890 Changes to past timestamps
1892 Several corrections were made for pre-1975 timestamps in Italy.
1893 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
1896 First, the 1893-11-01 00:00 transition in Italy used the new UT
1897 offset (+01), not the old (+00:49:56). (Thanks to Michael
1900 Second, rules for daylight saving in Italy were changed to agree
1901 with Italy's National Institute of Metrological Research (INRiM)
1902 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
1903 Inglis, and Michael Deckers):
1905 The 1916-06-03 transition was at 24:00, not 00:00.
1907 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
1910 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
1913 The 1944-09-17 transition was at 03:00, not 01:00. This
1914 particular change is taken from Italian law as INRiM's table,
1915 (which says 02:00) appears to have a typo here. Also, keep the
1916 1944-04-03 transition for Europe/Rome, as Rome was controlled by
1919 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
1924 The code should now be buildable on AmigaOS merely by setting the
1925 appropriate Makefile variables. (From a patch by Carsten Larsen.)
1928 Release 2016h - 2016-10-19 23:17:57 -0700
1930 Changes to future timestamps
1932 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
1933 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
1934 future fall transitions will be on the last Saturday of October
1935 at 01:00, which is consistent with predicted spring transitions
1936 on the last Saturday of March. (Thanks to Tim Parenti.)
1938 Changes to past timestamps
1940 In Turkey, transitions in 1986-1990 were at 01:00 standard time
1941 not at 02:00, and the spring 1994 transition was on March 20, not
1942 March 27. (Thanks to Kıvanç Yazan.)
1944 Changes to past and future time zone abbreviations
1946 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
1947 instead of alphabetic ones like "IST" and "LKT". Various
1948 English-language sources use "IST", "LKT" and "SLST", with no
1949 working consensus. (Usage of "SLST" mentioned by Sadika
1954 zic no longer mishandles relativizing file names when creating
1955 symbolic links like /etc/localtime, when these symbolic links
1956 are outside the usual directory hierarchy. This fixes a bug
1957 introduced in 2016g. (Problem reported by Andreas Stieger.)
1959 Changes to build procedure
1961 New rules 'traditional_tarballs' and 'traditional_signatures' for
1962 building just the traditional-format distribution. (Requested by
1965 The file 'version' is now put into the tzdata tarball too.
1966 (Requested by Howard Hinnant.)
1968 Changes to documentation and commentary
1970 The 'Theory' file now has a section on interface stability.
1971 (Requested by Paul Koning.) It also mentions features like
1972 tm_zone and localtime_rz that have long been supported by the
1975 tz-link.htm has improved coverage of time zone boundaries suitable
1976 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
1979 The US commentary now mentions Allen and the "day of two noons".
1981 The Fiji commentary mentions the government's 2016-10-03 press
1982 release. (Thanks to Raymond Kumar.)
1985 Release 2016g - 2016-09-13 08:56:38 -0700
1987 Changes to future timestamps
1989 Turkey switched from EET/EEST (+02/+03) to permanent +03,
1990 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
1991 than an invented abbreviation for the new time.
1993 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
1994 (Thanks to Tim Parenti.)
1996 Changes to past timestamps
1998 For America/Los_Angeles, spring-forward transition times have been
1999 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2002 For zones using Soviet time on 1919-07-01, transitions to UT-based
2003 time were at 00:00 UT, not at 02:00 local time. The affected
2004 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2005 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2007 Changes to past and future time zone abbreviations
2009 The Factory zone now uses the time zone abbreviation -00 instead
2010 of a long English-language string, as -00 is now the normal way to
2011 represent an undefined time zone.
2013 Several zones in Antarctica and the former Soviet Union, along
2014 with zones intended for ships at sea that cannot use POSIX TZ
2015 strings, now use numeric time zone abbreviations instead of
2016 invented or obsolete alphanumeric abbreviations. The affected
2017 zones are Antarctica/Casey, Antarctica/Davis,
2018 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2019 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2020 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2021 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2022 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2023 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2024 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2025 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2026 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2027 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2028 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2029 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2030 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2031 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2032 was replaced by +05, whereas MSK and MSD were kept as they are not
2033 our invention and are widely used.
2035 Changes to zone names
2037 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2038 (Thanks to David Massoud.)
2042 zic no longer generates binary files containing POSIX TZ-like
2043 strings that disagree with the local time type after the last
2044 explicit transition in the data. This fixes a bug with
2045 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2046 on the reference platform. (Thanks to Alexander Belopolsky for
2047 reporting the bug and suggesting a way forward.)
2049 If the installed localtime and/or posixrules files are symbolic
2050 links, zic now keeps them symbolic links when updating them, for
2051 compatibility with platforms like OpenSUSE where other programs
2052 configure these files as symlinks.
2054 zic now avoids hard linking to symbolic links, avoids some
2055 unnecessary mkdir and stat system calls, and uses shorter file
2058 zdump has a new -i option to generate transitions in a
2059 more-compact but still human-readable format. This option is
2060 experimental, and the output format may change in future versions.
2061 (Thanks to Jon Skeet for suggesting that an option was needed,
2062 and thanks to Tim Parenti and Chris Rovick for further comments.)
2064 Changes to build procedure
2066 An experimental distribution format is available, in addition
2067 to the traditional format which will continue to be distributed.
2068 The new format is a tarball tzdb-VERSION.tar.lz with signature
2069 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2070 tzdb-VERSION containing the code and data of the traditional
2071 two-tarball format, along with extra data that may be useful.
2072 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2073 for comments about the experimental format.)
2075 The release version number is now more accurate in the usual case
2076 where releases are built from a Git repository. For example, if
2077 23 commits and some working-file changes have been made since
2078 release 2016g, the version number is now something like
2079 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2080 Tagged releases use the same version number format as before,
2081 e.g., '2016g'. To support the more-accurate version number, its
2082 specification has moved from a line in the Makefile to a new
2083 source file 'version'.
2085 The experimental distribution contains a file to2050.tzs that
2086 contains what should be the output of 'zdump -i -c 2050' on
2087 primary zones. If this file is available, 'make check' now checks
2088 that zdump generates this output.
2090 'make check_web' now works on Fedora-like distributions.
2092 Changes to documentation and commentary
2094 tzfile.5 now documents the new restriction on POSIX TZ-like
2095 strings that is now implemented by zic.
2097 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2098 (Thanks to Alexander Belopolsky.)
2100 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2101 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2102 description of Java 8 has been brought up to date (thanks to
2103 Stephen Colebourne). Its description of local time on Mars has
2104 been updated to match current practice, and URLs have been updated
2105 and some obsolete ones removed.
2108 Release 2016f - 2016-07-05 16:26:51 +0200
2110 Changes affecting future timestamps
2112 The Egyptian government changed its mind on short notice, and
2113 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2114 (Thanks to Mina Samuel.)
2116 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2117 (Thanks to Stepan Golosunov.)
2119 Changes to past and future timestamps
2121 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2122 abbreviations instead of invented ones.
2124 Changes affecting past timestamps
2126 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2127 (Thanks to Stepan Golosunov.)
2130 Release 2016e - 2016-06-14 08:46:16 -0700
2132 Changes affecting future timestamps
2134 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2135 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2136 For future years, guess April's last Thursday to October's last
2137 Thursday except for Ramadan.
2139 Changes affecting past timestamps
2141 Locations while uninhabited now use '-00', not 'zzz', as a
2142 placeholder time zone abbreviation. This is inspired by Internet
2143 RFC 3339 and is more consistent with numeric time zone
2144 abbreviations already used elsewhere. The change affects several
2145 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2146 1920 and Antarctica/Troll before 2005.
2148 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2149 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2153 zic now outputs a dummy transition at time 2**31 - 1 in zones
2154 whose POSIX-style TZ strings contain a '<'. This mostly works
2155 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2156 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2158 Changes affecting documentation and commentary
2160 tz-link.htm says why governments should give plenty of notice for
2161 time zone or DST changes, and refers to Matt Johnson's blog post.
2163 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2166 Release 2016d - 2016-04-17 22:50:29 -0700
2168 Changes affecting future timestamps
2170 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2171 (Thanks to Alexander Krivenyshev for the heads-up.)
2173 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2174 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2176 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2177 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2178 at 02:00. (Thanks to Stepan Golosunov.)
2180 Changes affecting past timestamps
2182 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2183 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2184 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2185 the same change. (Thanks to Stepan Golosunov.)
2187 Russia and nearby locations had daylight-saving transitions on
2188 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2189 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2192 Many corrections to historical time in Kazakhstan from 1991
2193 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2194 invented time zone abbreviations with numeric abbreviations.
2196 Changes to commentary
2198 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2201 Release 2016c - 2016-03-23 00:51:27 -0700
2203 Changes affecting future timestamps
2205 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2207 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2208 Correa for the heads-up, and to Tim Parenti for corrections.)
2209 Guess that future transitions are August's and May's second
2210 Saturdays at 24:00 mainland time. Also, call the period from
2211 2014-09-07 through 2016-05-14 daylight saving time instead of
2212 standard time, as that seems more appropriate now.
2214 Changes affecting past timestamps
2216 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2217 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2218 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2219 (Thanks to Stepan Golosunov.)
2221 Changes to commentary
2223 Several updates and URLs for historical and proposed Russian changes.
2224 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2227 Release 2016b - 2016-03-12 17:30:14 -0800
2231 Starting with release 2016b, some data entries cause zic implementations
2232 derived from tz releases 2005j through 2015e to issue warnings like
2233 "time zone abbreviation differs from POSIX standard (+03)".
2234 These warnings should not otherwise affect zic's output and can safely be
2235 ignored on today's platforms, as the warnings refer to a restriction in
2236 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2237 warnings is to upgrade to zic derived from tz releases 2015f and later.
2239 Changes affecting future timestamps
2241 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2242 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2243 2016-03-27 at 02:00 local time. They need distinct zones since their
2244 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2245 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2246 and local time. The Astrakhan change is already official; the others have
2247 passed the first reading in the State Duma and are extremely likely.
2248 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2249 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2250 and Stepan Golosunov for followup.)
2252 As a trial of a new system that needs less information to be made up,
2253 the new zones use numeric time zone abbreviations like "+04"
2254 instead of invented abbreviations like "ASTT".
2256 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2259 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2260 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2261 Saturday at 01:00, not March's last Friday at 24:00.
2263 Changes affecting past timestamps
2265 Europe/Chisinau observed DST during 1990, and switched from +04 to
2266 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2267 (Thanks to Stepan Golosunov.)
2269 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2270 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2274 tzselect's diagnostics and checking, and checktab.awk's checking,
2275 have been improved. (Thanks to J William Piggott.)
2277 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2279 tzselect now tests Julian-date TZ settings more accurately.
2280 (Thanks to J William Piggott.)
2282 Changes to commentary
2284 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2286 tzselect again limits its menu comments so that menus fit on a
2287 24×80 alphanumeric display.
2289 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2291 In the Theory file, the description of possible time zone abbreviations in
2292 tzdata has been cleaned up, as the old description was unclear and
2293 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2296 Release 2016a - 2016-01-26 23:28:02 -0800
2298 Changes affecting future timestamps
2300 America/Cayman will not observe daylight saving this year after all.
2301 Revert our guess that it would. (Thanks to Matt Johnson.)
2303 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2304 (Thanks to Alexander Krivenyshev.)
2306 Asia/Tehran now has DST predictions for the year 2038 and later,
2307 to be March 21 00:00 to September 21 00:00. This is likely better
2308 than predicting no DST, albeit off by a day every now and then.
2310 Changes affecting past and future timestamps
2312 America/Metlakatla switched from PST all year to AKST/AKDT on
2313 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2315 America/Santa_Isabel has been removed, and replaced with a
2316 backward compatibility link to America/Tijuana. Its contents were
2317 apparently based on a misreading of Mexican legislation.
2319 Changes affecting past timestamps
2321 Asia/Karachi's two transition times in 2002 were off by a minute.
2322 (Thanks to Matt Johnson.)
2324 Changes affecting build procedure
2326 An installer can now combine leap seconds with use of the backzone file,
2327 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2328 The old 'make posix_packrat' rule is now marked as obsolescent.
2329 (Thanks to Ian Abbott for an initial implementation.)
2331 Changes affecting documentation and commentary
2333 A new file LICENSE makes it easier to see that the code and data
2334 are mostly public-domain. (Thanks to James Knight.) The three
2335 non-public-domain files now use the current (3-clause) BSD license
2336 instead of older versions of that license.
2338 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2339 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2340 on editing tz source files (with a mention of Sublime zoneinfo,
2341 thanks to Gilmore Davidson).
2343 The Theory and asia files now mention the 2015 book "The Global
2344 Transformation of Time, 1870-1950", and cite a couple of reviews.
2346 The America/Chicago entry now documents the informal use of US
2347 central time in Fort Pierre, South Dakota. (Thanks to Rick
2348 McDermid, Matt Johnson, and Steve Jones.)
2351 Release 2015g - 2015-10-01 00:39:51 -0700
2353 Changes affecting future timestamps
2355 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2358 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2359 (Thanks to Alexander Krivenyshev.)
2361 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2362 (Thanks to Ken Rylander.)
2364 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2365 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2366 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2368 Changes affecting past timestamps
2370 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2372 Changes affecting code
2374 localtime no longer mishandles America/Anchorage after 2037.
2375 (Thanks to Bradley White for reporting the bug.)
2377 On hosts with signed 32-bit time_t, localtime no longer mishandles
2378 Pacific/Fiji after 2038-01-16 14:00 UTC.
2380 The localtime module allows the variables 'timezone', 'daylight',
2381 and 'altzone' to be in common storage shared with other modules,
2382 and declares them in case the system <time.h> does not.
2383 (Problems reported by Kees Dekker.)
2385 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2386 This simplifies the code and is consistent with zdump.c.
2387 (Problem reported by Christos Zoulas.)
2389 Changes affecting documentation
2391 The tzfile man page now documents that transition times denote the
2392 starts (not the ends) of the corresponding time periods.
2393 (Ambiguity reported by Bill Seymour.)
2396 Release 2015f - 2015-08-10 18:06:56 -0700
2398 Changes affecting future timestamps
2400 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2401 The abbreviation remains "KST". (Thanks to Robert Elz.)
2403 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2406 Changes affecting past and future timestamps
2408 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2409 (Thanks to Roman Tudos.)
2411 Changes affecting data format and code
2413 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2414 field of a Rule line should now be '-'; the old values 'even',
2415 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2416 Although the implementation has not changed, these features do not
2417 work in the default installation, they are not used in the data,
2418 and they are now considered obsolescent.
2420 zic now checks that two rules don't take effect at the same time.
2421 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2422 simultaneity are now documented.
2424 The two characters '%z' in a zone format now stand for the UT
2425 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2426 five hours and thirty minutes ahead. This better supports time
2427 zone abbreviations conforming to POSIX.1-2001 and later.
2429 Changes affecting installed data files
2431 Comments for America/Halifax and America/Glace_Bay have been improved.
2432 (Thanks to Brian Inglis.)
2434 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2435 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2436 installed data files for Europe/Simferopol and Europe/Tallinn.
2437 It does not affect timestamps. (Thanks to Howard Hinnant.)
2439 Changes affecting code
2441 zdump and zic no longer warn about valid time zone abbreviations
2444 Some Visual Studio 2013 warnings have been suppressed.
2445 (Thanks to Kees Dekker.)
2447 'date' no longer sets the time of day and its -a, -d, -n and -t
2448 options have been removed. Long obsolescent, the implementation
2449 of these features had porting problems. Builders no longer need
2450 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2451 (Thanks to Kees Dekker for pointing out the problem.)
2453 Changes affecting documentation
2455 The Theory file mentions naming issues earlier, as these seem to be
2456 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2458 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2460 Mention that Herbert Samuel introduced the term "Summer Time".
2463 Release 2015e - 2015-06-13 10:56:02 -0700
2465 Changes affecting future timestamps
2467 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2468 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2470 Assume Cayman Islands will observe DST starting next year, using US rules.
2471 Although it isn't guaranteed, it is the most likely.
2473 Changes affecting data format
2475 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2476 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2478 Changes affecting code
2480 When displaying data, tzselect converts it to the current locale's
2481 encoding if the iconv command works. (Problem reported by random832.)
2483 tzselect no longer mishandles Dominica, fixing a bug introduced
2484 in Release 2014f. (Problem reported by Owen Leibman.)
2486 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2487 This fixes a bug introduced in Release 2014f.
2488 (Problem reported by Leonardo Chiquitto.)
2491 Release 2015d - 2015-04-24 08:09:46 -0700
2493 Changes affecting future timestamps
2495 Egypt will not observe DST in 2015 and will consider canceling it
2496 permanently. For now, assume no DST indefinitely.
2497 (Thanks to Ahmed Nazmy and Tim Parenti.)
2499 Changes affecting past timestamps
2501 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2502 1966-07-01. Also, Yukon's time zone history is documented better.
2503 (Thanks to Brian Inglis and Dennis Ferguson.)
2505 Change affecting past and future time zone abbreviations
2507 The abbreviations for Hawaii-Aleutian standard and daylight times
2508 have been changed from HAST/HADT to HST/HDT, as per US Government
2509 Printing Office style. This affects only America/Adak since 1983,
2510 as America/Honolulu was already using the new style.
2512 Changes affecting code
2514 zic has some minor performance improvements.
2517 Release 2015c - 2015-04-11 08:55:55 -0700
2519 Changes affecting future timestamps
2521 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2522 not 00:00 on April's last Friday. 2015's transition will therefore be on
2523 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2524 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2526 Changes affecting past timestamps
2528 The following changes affect some pre-1991 Chile-related timestamps
2529 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2531 The 1910 transition was January 10, not January 1.
2533 The 1918 transition was September 10, not September 1.
2535 The UT -04 time observed from 1932 to 1942 is now considered to
2536 be standard time, not year-round DST.
2538 Santiago observed DST (UT -03) from 1946-07-15 through
2539 1946-08-31, then reverted to standard time, then switched to -05
2542 Assume transitions before 1968 were at 00:00, since we have no data
2545 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2546 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2548 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2549 and omit all transitions on Pacific/Easter from 1942 through 1946
2550 since we have no data suggesting that they existed.
2552 One more zone has been turned into a link, as it differed
2553 from an existing zone only for older timestamps. As usual,
2554 this change affects UT offsets in pre-1970 timestamps only.
2555 The zone's old contents have been moved to the 'backzone' file.
2556 The affected zone is America/Montreal.
2558 Changes affecting commentary
2560 Mention the TZUpdater tool.
2562 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2565 Release 2015b - 2015-03-19 23:28:11 -0700
2567 Changes affecting future timestamps
2569 Mongolia will start observing DST again this year, from the last
2570 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2571 (Thanks to Ganbold Tsagaankhuu.)
2573 Palestine will start DST on March 28, not March 27. Also,
2574 correct the fall 2014 transition from September 26 to October 24.
2575 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2577 Changes affecting past timestamps
2579 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2580 regression. (Thanks to Stuart Bishop for reporting the problem.)
2582 Some more zones have been turned into links, when they differed
2583 from existing zones only for older timestamps. As usual,
2584 these changes affect UT offsets in pre-1970 timestamps only.
2585 Their old contents have been moved to the 'backzone' file.
2586 The affected zones are: America/Antigua, America/Cayman,
2587 Pacific/Midway, and Pacific/Saipan.
2589 Changes affecting time zone abbreviations
2591 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2594 Changes affecting code
2596 Fix integer overflow bug in reference 'mktime' implementation.
2597 (Problem reported by Jörg Richter.)
2599 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2600 to be used in the same executable as standard-library time_t functions.
2601 (Problems reported by Bradley White.)
2603 Changes affecting commentary
2605 Cite the recent Mexican decree changing Quintana Roo's time zone.
2606 (Thanks to Carlos Raúl Perasso.)
2608 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2610 Update info about Mars time.
2613 Release 2015a - 2015-01-29 22:35:20 -0800
2615 Changes affecting future timestamps
2617 The Mexican state of Quintana Roo, represented by America/Cancun,
2618 will shift from Central Time with DST to Eastern Time without DST
2619 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2621 Chile will not change clocks in April or thereafter; its new standard time
2622 will be its old daylight saving time. This affects America/Santiago,
2623 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2625 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2626 (Thanks to Tim Parenti.)
2628 Changes affecting past timestamps
2630 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2631 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2632 Shanks about time in Iceland between 1837 and 1908.
2634 Some more zones have been turned into links, when they differed
2635 from existing zones only for older timestamps. As usual,
2636 these changes affect UT offsets in pre-1970 timestamps only.
2637 Their old contents have been moved to the 'backzone' file.
2638 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2641 Changes affecting code
2643 tzalloc now scrubs time zone abbreviations compatibly with the way
2644 that tzset always has, by replacing invalid bytes with '_' and by
2645 shortening too-long abbreviations.
2647 tzselect ports to POSIX awk implementations, no longer mishandles
2648 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2649 settings to the user. (Thanks to Stefan Kuhn.)
2651 Changes affecting build procedure
2653 'make check' now checks for links to links in the data.
2654 One such link (for Africa/Asmera) has been fixed.
2655 (Thanks to Stephen Colebourne for pointing out the problem.)
2657 Changes affecting commentary
2659 The leapseconds file commentary now mentions the expiration date.
2660 (Problem reported by Martin Burnicki.)
2662 Update Mexican Library of Congress URL.
2665 Release 2014j - 2014-11-10 17:37:11 -0800
2667 Changes affecting current and future timestamps
2669 Turks & Caicos' switch from US eastern time to UT -04 year-round
2670 did not occur on 2014-11-02 at 02:00. It's currently scheduled
2671 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
2673 Changes affecting past timestamps
2675 Many pre-1989 timestamps have been corrected for Asia/Seoul and
2676 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2677 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
2678 longer guess that Pyongyang mimicked Seoul time after World War II,
2679 as this is politically implausible.
2681 Some more zones have been turned into links, when they differed
2682 from existing zones only for older timestamps. As usual,
2683 these changes affect UT offsets in pre-1970 timestamps only.
2684 Their old contents have been moved to the 'backzone' file.
2685 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2686 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2687 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2690 Changes affecting commentary
2692 The commentary is less enthusiastic about Shanks as a source,
2693 and is more careful to distinguish UT from UTC.
2696 Release 2014i - 2014-10-21 22:04:57 -0700
2698 Changes affecting future timestamps
2700 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2701 (Thanks to Ken Rylander for the heads-up.) Guess that future
2702 years will use a similar pattern.
2704 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2705 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2706 (Thanks to Kiley Walbom for the heads-up.)
2708 Changes affecting time zone abbreviations
2710 Since Belarus is not changing its clocks even though Moscow is,
2711 the time zone abbreviation in Europe/Minsk is changing from FET
2712 to its more-traditional value MSK on 2014-10-26 at 01:00.
2713 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2715 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2716 Indochina, to distinguish it better from ICT (+07).
2718 Changes affecting past timestamps
2720 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2721 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2722 authoritative book). Asia/Ho_Chi_Minh has been added to
2723 zone1970.tab, to give tzselect users in Vietnam two choices,
2724 since north and south Vietnam disagreed after our 1970 cutoff.
2726 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2727 they differed from existing zones only for older timestamps. As
2728 usual, these changes affect pre-1970 timestamps only. Their old
2729 contents have been moved to the 'backzone' file.
2731 Changes affecting code
2733 The time-related library functions now set errno on failure, and
2734 some crashes in the new tzalloc-related library functions have
2735 been fixed. (Thanks to Christos Zoulas for reporting most of
2736 these problems and for suggesting fixes.)
2738 If USG_COMPAT is defined and the requested timestamp is standard time,
2739 the tz library's localtime and mktime functions now set the extern
2740 variable timezone to a value appropriate for that timestamp; and
2741 similarly for ALTZONE, daylight saving time, and the altzone variable.
2742 This change is a companion to the tzname change in 2014h, and is
2743 designed to make timezone and altzone more compatible with tzname.
2745 The tz library's functions now set errno to EOVERFLOW if they fail
2746 because the result cannot be represented. ctime and ctime_r now
2747 return NULL and set errno when a timestamp is out of range, rather
2748 than having undefined behavior.
2750 Some bugs associated with the new 2014g functions have been fixed.
2751 This includes a bug that largely incapacitated the new functions
2752 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
2753 It also includes some uses of uninitialized variables after tzalloc.
2754 The new code uses the standard type 'ssize_t', which the Makefile
2755 now gives porting advice about.
2757 Changes affecting commentary
2759 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2762 Release 2014h - 2014-09-25 18:59:03 -0700
2764 Changes affecting past timestamps
2766 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2768 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2769 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
2771 Some more zones have been turned into links, when they differed
2772 from existing zones only for older timestamps. As usual,
2773 these changes affect UT offsets in pre-1970 timestamps only.
2774 Their old contents have been moved to the 'backzone' file.
2775 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2776 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2777 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2779 Changes affecting code
2781 zdump -V and -v now output gmtoff= values on all platforms,
2782 not merely on platforms defining TM_GMTOFF.
2784 The tz library's localtime and mktime functions now set tzname to a value
2785 appropriate for the requested timestamp, and zdump now uses this
2786 on platforms not defining TM_ZONE, fixing a 2014g regression.
2787 (Thanks to Tim Parenti for reporting the problem.)
2789 The tz library no longer sets tzname if localtime or mktime fails.
2791 zdump -c no longer mishandles transitions near year boundaries.
2792 (Thanks to Tim Parenti for reporting the problem.)
2794 An access to uninitialized data has been fixed.
2795 (Thanks to Jörg Richter for reporting the problem.)
2797 When THREAD_SAFE is defined, the code ports to the C11 memory model.
2798 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2799 and two threads race to initialize data used by gmtime-like functions.
2800 (Thanks to Andy Heninger for reporting the problems.)
2802 Changes affecting build procedure
2804 'make check' now checks better for properly-sorted data.
2806 Changes affecting documentation and commentary
2808 zdump's gmtoff=N output is now documented, and its isdst=D output
2809 is now documented to possibly output D values other than 0 or 1.
2811 zdump -c's treatment of years is now documented to use the
2812 Gregorian calendar and Universal Time without leap seconds,
2813 and its behavior at cutoff boundaries is now documented better.
2814 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2816 Programs are now documented to use the proleptic Gregorian calendar.
2817 (Thanks to Alan Barrett for the suggestion.)
2819 Fractional-second GMT offsets have been documented for civil time
2820 in 19th-century Chennai, Jakarta, and New York.
2823 Release 2014g - 2014-08-28 12:31:23 -0700
2825 Changes affecting future timestamps
2827 Turks & Caicos is switching from US eastern time to UT -04
2828 year-round, modeled as a switch on 2014-11-02 at 02:00.
2829 [As noted in 2014j, this switch was later delayed.]
2831 Changes affecting past timestamps
2833 Time in Russia or the USSR before 1926 or so has been corrected by
2834 a few seconds in the following zones: Asia/Irkutsk,
2835 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
2836 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
2837 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
2838 Vladimir Karpinsky.)
2840 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
2841 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
2842 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
2843 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
2844 (Thanks to Stephen Colebourne for pointing to the decree.)
2846 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
2848 A new file 'backzone' contains data which may appeal to
2849 connoisseurs of old timestamps, although it is out of scope for
2850 the tz database, is often poorly sourced, and contains some data
2851 that is known to be incorrect. The new file is not recommended
2852 for ordinary use and its entries are not installed by default.
2853 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
2854 Isle of Man entries.)
2856 Some more zones have been turned into links, when they differed
2857 from existing zones only for older timestamps. As usual,
2858 these changes affect UT offsets in pre-1970 timestamps only.
2859 Their old contents have been moved to the 'backzone' file.
2860 The affected zones are: Africa/Bangui, Africa/Brazzaville,
2861 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
2862 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
2864 Changes affecting code
2866 Unless NETBSD_INSPIRED is defined to 0, the tz library now
2867 supplies functions for creating and using objects that represent
2868 timezones. The new functions are tzalloc, tzfree, localtime_rz,
2869 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
2870 time2posix_z. They are intended for performance: for example,
2871 localtime_rz (unlike localtime_r) is trivially thread-safe without
2872 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
2873 functions, and to Alan Barrett and Jonathan Lennox for helping to
2876 zdump now builds with the tz library unless USE_LTZ is defined to 0,
2877 This lets zdump use tz features even if the system library lacks them.
2878 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
2879 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
2881 zdump now uses localtime_rz if available, as it's significantly faster,
2882 and it can help zdump better diagnose invalid timezone names.
2883 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
2884 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
2885 not available, zdump now uses localtime_r and tzset if available,
2886 as this is a bit cleaner and faster than plain localtime. Compile
2887 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
2888 lacks these two functions.
2890 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
2891 Although not needed for tz's own applications, which are single-threaded,
2892 this supports POSIX better if the tz library is used in multithreaded apps.
2894 Some crashes have been fixed when zdump or the tz library is given
2895 invalid or outlandish input.
2897 The tz library no longer mishandles leap seconds on platforms with
2898 unsigned time_t in timezones that lack ordinary transitions after 1970.
2900 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
2901 already defined, to make it easier to configure on common platforms.
2902 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
2904 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
2905 assumes that reading uninitialized memory yields garbage values
2906 but does not cause other problems such as traps.
2908 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
2909 more likely to guess right for ambiguous timestamps near
2910 transitions where tm_isdst does not change.
2912 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
2913 strftime_l for compatibility with recent versions of POSIX.
2914 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
2915 to 1 on recent POSIX versions, and to 0 otherwise.
2917 tzselect -c now uses a hybrid distance measure that works better
2918 in Africa. (Thanks to Alan Barrett for noting the problem.)
2920 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
2921 or when time_tz is defined.
2923 When HAVE_UTMPX_H is set the 'date' command now builds on systems
2924 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
2925 the date it updates the wtmpx file if _PATH_WTMPX is defined.
2926 This affects GNU/Linux and similar systems.
2928 For easier maintenance later, some C code has been simplified,
2929 some lint has been removed, and the code has been tweaked so that
2930 plain 'make' is more likely to work.
2932 The C type 'bool' is now used for boolean values, instead of 'int'.
2934 The long-obsolete LOCALE_HOME code has been removed.
2936 The long-obsolete 'gtime' function has been removed.
2938 Changes affecting build procedure
2940 'zdump' no longer links in ialloc.o, as it's not needed.
2942 'make check_time_t_alternatives' no longer assumes GNU diff.
2944 Changes affecting distribution tarballs
2946 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
2947 the tzdata tarball instead of the tzcode tarball, since they help
2948 maintain the data. The NEWS and Theory files are now also
2949 distributed in the tzdata tarball, as they're relevant for data.
2950 (Thanks to Alan Barrett for pointing this out.) Also, the
2951 leapseconds.awk file is no longer distributed in the tzcode
2952 tarball, since it belongs in the tzdata tarball (where 2014f
2953 inadvertently also distributed it).
2955 Changes affecting documentation and commentary
2957 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
2958 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
2961 The man pages have been updated to use function prototypes,
2962 to document thread-safe variants like localtime_r, and to document
2963 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
2966 The fields in Link lines have been renamed to be more descriptive
2967 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
2968 and LINK-TO has become LINK-NAME.
2970 tz-link.htm mentions the IETF's tzdist working group; Windows
2971 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
2973 Some broken URLs have been fixed in the commentary. (Thanks to
2976 Commentary about Philippines DST has been updated, and commentary
2977 on pre-1970 time in India has been added.
2980 Release 2014f - 2014-08-05 17:42:36 -0700
2982 Changes affecting future timestamps
2984 Russia will subtract an hour from most of its time zones on 2014-10-26
2985 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
2986 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
2987 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
2988 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
2989 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
2990 (Europe/Samara) are not changing their clocks. The changed zones are
2991 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
2992 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
2993 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
2994 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
2995 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
2996 but not its UTC offset. Two zones are added: Asia/Chita (split
2997 from Asia/Yakutsk, and also with two hours subtracted) and
2998 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
2999 subtracted). (Thanks to Tim Parenti for much of the above.)
3001 Changes affecting time zone abbreviations
3003 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3004 and similarly for the other Australian zones. That is, for eastern
3005 standard and daylight saving time the abbreviations are AEST and AEDT
3006 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3007 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3008 This change does not affect UT offsets, only time zone abbreviations.
3009 (Thanks to Rich Tibbett and many others.)
3011 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3012 effective 2014-10-26 at 02:00 local time.
3014 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3015 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3017 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3018 Similarly, prefer EET/EEST for eastern European time in Russia.
3020 Change time zone abbreviations in (western) Samoa to use "ST" and
3021 "DT" suffixes, as this is more likely to match common practice.
3022 Prefix "W" to (western) Samoa time when its standard-time offset
3023 disagrees with that of American Samoa.
3025 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3027 Time zone abbreviations have been updated for Japan's two time
3028 zones used 1896-1937. JWST now stands for Western Standard
3029 Time, and JCST for Central Standard Time (formerly this was CJT).
3030 These abbreviations are now used for time in Korea, Taiwan,
3031 and Sakhalin while controlled by Japan.
3033 Changes affecting past timestamps
3035 China's five zones have been simplified to two, since the post-1970
3036 differences in the other three seem to have been imaginary. The
3037 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3038 removed; backwards-compatibility links still work, albeit with
3039 different behaviors for timestamps before May 1980. Asia/Urumqi's
3040 1980 transition to UT +08 has been removed, so that it is now at
3041 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3042 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3044 Some zones have been turned into links, when they differed from existing
3045 zones only for older UT offsets where data entries were likely invented.
3046 These changes affect UT offsets in pre-1970 timestamps only. This is
3047 similar to the change in release 2013e, except this time for western
3048 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3049 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3050 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3051 Atlantic/St_Helena. This also affects the backwards-compatibility
3052 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3053 Tim Parenti, and David Patte for reporting problems in earlier
3054 versions of this change.)
3056 Asia/Shanghai's pre-standard-time UT offset has been changed from
3057 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3058 transition to standard time has been changed from 1928 to 1901.
3060 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3061 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3062 In 1946 it observed DST from 05-15 through 09-30; in 1947
3063 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3064 (Thanks to Yu-Cheng Chuang.)
3066 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3068 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3069 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3071 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3072 period from 1911 to 1950.
3074 Pacific/Chatham has been changed to New Zealand standard time plus
3075 45 minutes for the period before 1957, reflecting a 1956 remark in
3076 the New Zealand parliament.
3078 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3079 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3080 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3081 not 04-06 at 02:00; and there was no DST in 1920.
3083 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3085 Time in Russia before 1927 or so has been corrected by a few seconds in
3086 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3087 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3088 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3089 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3091 Changes affecting data format
3093 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3094 The new file's extended format allows multiple country codes per zone.
3095 The older file is still installed but is deprecated; its format is
3096 not changing and it will still be distributed for a while, but new
3097 applications should use the new file.
3099 The new file format simplifies maintenance of obscure locations.
3100 To test this, it adds coverage for the Crozet Islands and the
3101 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3103 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3104 It is still ASCII now, but commentary about the switch has been added.
3105 The new file 'zone1970.tab' already uses UTF-8.
3107 Changes affecting code
3109 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3110 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3112 'zic' no longer mishandles input when ignoring case in locales that
3113 are not compatible with English, e.g., unibyte Turkish locales when
3114 compiled with HAVE_GETTEXT.
3116 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3117 they no longer use ASCII '-' as if it were a dash.
3119 'zic' now rejects output file names that contain '.' or '..' components.
3120 (Thanks to Tim Parenti for reporting the problem.)
3122 'zic -v' now warns about output file names that do not follow
3123 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3124 David Olson for starting the ball rolling on this.)
3126 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3128 Changes affecting build procedure
3130 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3131 (Thanks to John Cochran.)
3133 Changes affecting documentation and commentary
3135 The 'Theory' file documents legacy names, the longstanding
3136 exceptions to the POSIX-inspired file name rules.
3138 The 'zic' documentation clarifies the role of time types when
3139 interpreting dates. (Thanks to Arthur David Olson.)
3141 Documentation and commentary now prefer UTF-8 to US-ASCII,
3142 allowing the use of proper accents in foreign words and names.
3143 Code and data have not changed because of this. (Thanks to
3144 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3147 Non-HTML documentation and commentary now use plain-text URLs instead of
3148 HTML insertions, and are more consistent about bracketing URLs when they
3149 are not already surrounded by white space. (Thanks to suggestions by
3152 There is new commentary about Xujiahui Observatory, the five time-zone
3153 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3154 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3155 warlord Jin Shuren in the data.
3157 Commentary about the coverage of each Russian zone has been standardized.
3158 (Thanks to Tim Parenti.)
3160 There is new commentary about contemporary timekeeping in Ethiopia.
3162 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3164 There is new commentary about time in Poland in 1919.
3166 Proper credit has been given to DST inventor George Vernon Hudson.
3168 Commentary about time in Metlakatla, AK and Resolute, NU has been
3169 improved, with a new source for the former.
3171 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3174 Commentary about permanent Antarctic bases has been updated.
3176 Several typos have been corrected. (Thanks to Tim Parenti for
3177 contributing some of these fixes.)
3179 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3180 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3181 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3182 (Thanks to a heads-up from Dirkjan Ochtman.)
3184 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3185 have been removed. These obsolescent US Naval Observatory entries were no
3186 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3189 Release 2014e - 2014-06-12 21:53:52 -0700
3191 Changes affecting near-future timestamps
3193 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3194 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3195 switch to standard time at 24:00 the last Thursday before Ramadan, and
3196 back to DST at 00:00 the first Friday after Ramadan.
3198 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3199 to Milamber Space Network.) Guess that from 2015 on Morocco will
3200 temporarily switch to standard time at 03:00 the last Saturday before
3201 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3203 Changes affecting past timestamps
3205 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3206 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3207 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3208 in 1991. (Thanks to Hank W. for reporting the problems.)
3210 Changes affecting commentary
3212 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3213 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3214 removes stale pointers to World Time Explorer and WORLDTIME.
3217 Release 2014d - 2014-05-27 21:34:40 -0700
3219 Changes affecting code
3221 zic no longer generates files containing timestamps before the Big Bang.
3222 This works around GNOME glib bug 878
3223 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3224 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3225 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3227 Changes affecting documentation
3229 tz-link.htm now mentions GNOME.
3232 Release 2014c - 2014-05-13 07:44:13 -0700
3234 Changes affecting near-future timestamps
3236 Egypt observes DST starting 2014-05-15 at 24:00.
3237 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3238 Details have not been announced, except that DST will not be observed
3239 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3240 Morocco, and that Egypt's future spring and fall transitions will be the
3241 same as 2010 when it last observed DST, namely April's last Friday at
3242 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3243 that Ramadan transitions will be at 00:00 standard time.
3245 Changes affecting code
3247 zic now generates transitions for minimum time values, eliminating guesswork
3248 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3250 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3252 Changes affecting commentary and documentation
3254 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3257 Release 2014b - 2014-03-24 21:28:50 -0700
3259 Changes affecting near-future timestamps
3261 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3262 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3264 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3265 Bengt-Inge Larsson.) This is currently an approximation; a better version
3266 will require the zic and localtime fixes mentioned below, and the plan is
3267 to wait for a while until at least the zic fixes propagate.
3269 Changes affecting code
3271 'zic' and 'localtime' no longer reject locations needing four transitions
3272 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3273 Also, 'zic' avoids some unlikely failures due to integer overflow.
3275 Changes affecting build procedure
3277 'make check' now detects Rule lines defined but never used.
3278 The NZAQ rules, an instance of this problem, have been removed.
3280 Changes affecting commentary and documentation
3282 Fix Tuesday/Thursday typo in description of time in Israel.
3283 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3285 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3286 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3287 library supports them.
3289 Add comments about Johnston Island time in the 1960s.
3290 (Thanks to Lyle McElhaney.)
3292 Morocco's 2014 DST start will be as predicted.
3293 (Thanks to Sebastien Willemijns.)
3296 Release 2014a - 2014-03-07 23:30:29 -0800
3298 Changes affecting near-future timestamps
3300 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3301 the heads-up, and to Tim Parenti for simplifying the update.)
3303 Changes affecting past timestamps
3305 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
3306 (Thanks to Steffen Thorsen.)
3308 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3309 (not 1992-01-01), and observed DST during the entire next winter.
3310 (Thanks to Vladimir in Moscow via Alois Treindl.)
3312 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3313 (Thanks to Avigdor Finkelstein.)
3315 Changes affecting code
3317 A uninitialized-storage bug in 'localtime' has been fixed.
3318 (Thanks to Logan Chien.)
3320 Changes affecting the build procedure
3322 The settings for 'make check_web' now default to Ubuntu 13.10.
3324 Changes affecting commentary and documentation
3326 The boundary of the US Pacific time zone is given more accurately.
3327 (Thanks to Alan Mintz.)
3329 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3331 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3333 Better descriptions of countries with same time zone history as
3334 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3336 Several changes affect tz-link.htm, the main web page.
3338 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3341 Mention xCal (Internet RFC 6321) and jCal.
3343 Microsoft has some support for tz database names.
3345 CLDR data formats include both XML and JSON.
3347 Mention Maggiolo's map of solar vs standard time.
3348 (Thanks to Arthur David Olson.)
3350 Mention TZ4Net. (Thanks to Matt Johnson.)
3352 Mention the timezone-olson Haskell package.
3354 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3356 Remove moribund links to daylight-savings-time.info and to
3357 Simple Timer + Clocks.
3359 Update two links. (Thanks to Oscar van Vlijmen.)
3361 Fix some formatting glitches, e.g., remove random newlines from
3362 abbr elements' title attributes.
3365 Release 2013i - 2013-12-17 07:25:23 -0800
3367 Changes affecting near-future timestamps:
3369 Jordan switches back to standard time at 00:00 on December 20, 2013.
3370 The 2006-2011 transition schedule is planned to resume in 2014.
3371 (Thanks to Steffen Thorsen.)
3373 Changes affecting past timestamps:
3375 In 2004, Cuba began DST on March 28, not April 4.
3376 (Thanks to Steffen Thorsen.)
3378 Changes affecting code
3380 The compile-time flag NOSOLAR has been removed, as nowadays the
3381 benefit of slightly shrinking runtime table size is outweighed by the
3382 cost of disallowing potential future updates that exceed old limits.
3384 Changes affecting documentation and commentary
3386 The files solar87, solar88, and solar89 are no longer distributed.
3387 They were a negative experiment - that is, a demonstration that
3388 tz data can represent solar time only with some difficulty and error.
3389 Their presence in the distribution caused confusion, as Riyadh
3390 civil time was generally not solar time in those years.
3392 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3395 Release 2013h - 2013-10-25 15:32:32 -0700
3397 Changes affecting current and future timestamps:
3399 Libya has switched its UT offset back to +02 without DST, instead
3400 of +01 with DST. (Thanks to Even Scharning.)
3402 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3403 (Thanks to Gwillim Law.)
3405 Changes affecting future timestamps:
3407 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3408 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3409 (Thanks to Steffen Thorsen.)
3411 Add entries for DST transitions in Morocco in the year 2038.
3412 This avoids some year-2038 glitches introduced in 2013g.
3413 (Thanks to Yoshito Umaoka for reporting the problem.)
3415 Changes affecting API
3417 The 'tzselect' command no longer requires the 'select' command,
3418 and should now work with /bin/sh on more platforms. It also works
3419 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3420 Patrick 'P. J.' McDermott and Alan Barrett.)
3422 Changes affecting code
3424 Fix localtime overflow bugs with 32-bit unsigned time_t.
3426 zdump no longer assumes sscanf returns maximal values on overflow.
3428 Changes affecting the build procedure
3430 The builder can specify which programs to use, if any, instead of
3431 'ar' and 'ranlib', and libtz.a is now built locally before being
3432 installed. (Thanks to Michael Forney.)
3434 A dependency typo in the 'zdump' rule has been fixed.
3435 (Thanks to Andrew Paprocki.)
3437 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3438 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3440 'make clean' no longer removes 'leapseconds', since it's
3441 host-independent and is part of the distribution.
3443 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3445 Changes affecting documentation and commentary
3447 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3448 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3450 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3451 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3452 longer maintained) and for old advisories. SOFA now does C.
3454 Release 2013g - 2013-09-30 21:08:26 -0700
3456 Changes affecting current and near-future timestamps
3458 Morocco now observes DST from the last Sunday in March to the last
3459 Sunday in October, not April to September respectively. (Thanks
3460 to Steffen Thorsen.)
3462 Changes affecting 'zic'
3464 'zic' now runs on platforms that lack both hard links and symlinks.
3465 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3466 Also, fix some bugs on platforms that lack hard links but have symlinks.
3468 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3469 to predict the far future, fixing a bug introduced in 2013e.
3471 Changes affecting the build procedure
3473 The 'leapseconds' file is again put into the tzdata tarball.
3474 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3475 Matt Burgess and Ian Abbott.) The timestamps of these and other
3476 dependent files in tarballs are adjusted more consistently.
3478 Changes affecting documentation and commentary
3480 The README file is now part of the data tarball as well as the code.
3481 It now states that files are public domain unless otherwise specified.
3482 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3483 Its details about the 1989 release moved to a place of honor near
3487 Release 2013f - 2013-09-24 23:37:36 -0700
3489 Changes affecting near-future timestamps
3491 Tocantins will very likely not observe DST starting this spring.
3492 (Thanks to Steffen Thorsen.)
3494 Jordan will likely stay at UT +03 indefinitely, and will not fall
3497 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3499 Changes affecting API
3501 The types of the global variables 'timezone' and 'altzone' (if present)
3502 have been changed back to 'long'. This is required for 'timezone'
3503 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3504 These variables were originally 'long' in the tz code, but were
3505 mistakenly changed to 'time_t' in 1987; nobody reported the
3506 incompatibility until now. The difference matters on x32, where
3507 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3509 Changes affecting the build procedure
3511 Avoid long strings in leapseconds.awk to work around a mawk bug.
3512 (Thanks to Cyril Baurand.)
3514 Changes affecting documentation and commentary
3516 New file 'NEWS' that contains release notes like this one.
3518 Paraguay's law does not specify DST transition time; 00:00 is customary.
3519 (Thanks to Waldemar Villamayor-Venialbo.)
3521 Minor capitalization fixes.
3523 Changes affecting version-control only
3525 The experimental GitHub repository now contains annotated and
3526 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3527 Releases are tagged starting with 2012e; earlier releases were
3528 done differently, and tags would either not have a simple name or
3529 not exactly match what was released.
3531 'make set-timestamps' is now simpler and a bit more portable.
3534 Release 2013e - 2013-09-19 23:50:04 -0700
3536 Changes affecting near-future timestamps
3538 This year Fiji will start DST on October 27, not October 20.
3539 (Thanks to David Wheeler for the heads-up.) For now, guess that
3540 Fiji will continue to spring forward the Sunday before the fourth
3543 Changes affecting current and future time zone abbreviations
3545 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3546 time zone abbreviations since 1932. (Thanks to George Ziegler,
3547 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3548 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3549 Asia/Makassar, and Asia/Pontianak.
3551 Use ART (UT -03, standard time), rather than WARST (also -03, but
3552 daylight saving time) for San Luis, Argentina since 2009.
3554 Changes affecting Godthåb timestamps after 2037 if version mismatch
3556 Allow POSIX-like TZ strings where the transition time's hour can
3557 range from -167 through 167, instead of the POSIX-required 0
3558 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3559 new Fiji rules. This is a more-compact way to represent
3560 far-future timestamps for America/Godthab, America/Santiago,
3561 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3562 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3563 this change. (Derived from a suggestion by Arthur David Olson.)
3565 Allow POSIX-like TZ strings where daylight saving time is in
3566 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3567 Argentina Summer Time all year. This supports a more-compact way
3568 to represent the 2013d data for America/Argentina/San_Luis.
3569 Because of the change for San Luis noted above this change does not
3570 affect the current data. (Thanks to Andrew Main (Zefram) for
3571 suggestions that improved this change.)
3573 Where these two TZ changes take effect, there is a minor extension
3574 to the tz file format in that it allows new values for the
3575 embedded TZ-format string, and the tz file format version number
3576 has therefore been increased from 2 to 3 as a precaution.
3577 Version-2-based client code should continue to work as before for
3578 all timestamps before 2038. Existing version-2-based client code
3579 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3580 files, and typically works in practice even for timestamps after
3581 2037; the only known exception is America/Godthab.
3583 Changes affecting timestamps before 1970
3585 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3586 some errors before 1947.
3588 Some zones have been turned into links, when they differ from existing
3589 zones only in older data entries that were likely invented or that
3590 differ only in LMT or transitions from LMT. These changes affect
3591 only timestamps before 1943. The affected zones are:
3592 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3593 America/Grenada, America/Guadeloupe, America/Marigot,
3594 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3595 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3596 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3597 confirming that the old Europe/Vaduz zone was wrong and the new
3598 link is better for WWII-era times.)
3600 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3601 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3604 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3605 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3608 Change the date of the circa-1850 Zurich transition from 1849-09-12
3609 to 1853-07-16, overriding Shanks with data from Messerli about
3610 postal and telegraph time in Switzerland.
3612 Changes affecting time zone abbreviations before 1970
3614 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3615 as Jakarta was called Batavia back then.
3617 Changes affecting API
3619 The 'zic' command now outputs a dummy transition when far-future
3620 data can't be summarized using a TZ string, and uses a 402-year
3621 window rather than a 400-year window. For the current data, this
3622 affects only the Asia/Tehran file. It does not affect any of the
3623 timestamps that this file represents, so zdump outputs the same
3624 information as before. (Thanks to Andrew Main (Zefram).)
3626 The 'date' command has a new '-r' option, which lets you specify
3627 the integer time to display, a la FreeBSD.
3629 The 'tzselect' command has two new options '-c' and '-n', which lets you
3630 select a zone based on latitude and longitude.
3632 The 'zic' command's '-v' option now warns about constructs that
3633 require the new version-3 binary file format. (Thanks to Arthur
3634 David Olson for the suggestion.)
3636 Support for floating-point time_t has been removed.
3637 It was always dicey, and POSIX no longer requires it.
3638 (Thanks to Eric Blake for suggesting to the POSIX committee to
3639 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3640 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3641 bugs and elucidating some of the corners of the old floating-point
3644 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3645 changed back to the old practice of using 'long' to represent UT
3646 offsets. This had been inadvertently and mistakenly changed to
3647 'int_fast32_t'. (Thanks to Christos Zoulas.)
3649 The code avoids undefined behavior on integer overflow in some
3650 more places, including gmtime, localtime, mktime and zdump.
3652 Changes affecting the zdump utility
3654 zdump now outputs "UT" when referring to Universal Time, not "UTC".
3655 "UTC" does not make sense for timestamps that predate the introduction
3656 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
3657 for clarifying UT vs UTC.)
3659 Data changes affecting behavior of tzselect and similar programs
3661 Country code BQ is now called the more-common name "Caribbean Netherlands"
3662 rather than the more-official "Bonaire, St Eustatius & Saba".
3664 Remove from zone.tab the names America/Montreal, America/Shiprock,
3665 and Antarctica/South_Pole, as they are equivalent to existing
3666 same-country-code zones for post-1970 timestamps. The data entries for
3667 these names are unchanged, so the names continue to work as before.
3669 Changes affecting code internals
3671 zic -c now runs way faster on 64-bit hosts when given large numbers.
3673 zic now uses vfprintf to avoid allocating and freeing some memory.
3675 tzselect now computes the list of continents from the data,
3676 rather than have it hard-coded.
3678 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3680 Changes affecting the build procedure
3682 The 'leapseconds' file is now generated automatically from a
3683 new file 'leap-seconds.list', which is a copy of
3684 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3685 A new source file 'leapseconds.awk' implements this.
3686 The goal is simplification of the future maintenance of 'leapseconds'.
3688 When building the 'posix' or 'right' subdirectories, if the
3689 subdirectory would be a copy of the default subdirectory, it is
3690 now made a symbolic link if that is supported. This saves about
3691 2 MB of file system space.
3693 The links America/Shiprock and Antarctica/South_Pole have been
3694 moved to the 'backward' file. This affects only nondefault builds
3695 that omit 'backward'.
3697 Changes affecting version-control only
3699 .gitignore now ignores 'date'.
3701 Changes affecting documentation and commentary
3703 Changes to the 'tzfile' man page
3705 It now mentions that the binary file format may be extended in
3706 future versions by appending data.
3708 It now refers to the 'zdump' and 'zic' man pages.
3710 Changes to the 'zic' man page
3712 It lists conditions that elicit a warning with '-v'.
3714 It says that the behavior is unspecified when duplicate names
3715 are given, or if the source of one link is the target of another.
3717 Its examples are updated to match the latest data.
3719 The definition of white space has been clarified slightly.
3720 (Thanks to Michael Deckers.)
3722 Changes to the 'Theory' file
3724 There is a new section about the accuracy of the tz database,
3725 describing the many ways that errors can creep in, and
3726 explaining why so many of the pre-1970 timestamps are wrong or
3727 misleading (thanks to Steve Allen, Lester Caine, and Garrett
3728 Wollman for discussions that contributed to this).
3730 The 'Theory' file describes LMT better (this follows a
3731 suggestion by Guy Harris).
3733 It refers to the 2013 edition of POSIX rather than the 2004 edition.
3735 It's mentioned that excluding 'backward' should not affect the
3736 other data, and it suggests at least one zone.tab name per
3737 inhabited country (thanks to Stephen Colebourne).
3739 Some longstanding restrictions on names are documented, e.g.,
3740 'America/New_York' precludes 'America/New_York/Bronx'.
3742 It gives more reasons for the 1970 cutoff.
3744 It now mentions which time_t variants are supported, such as
3745 signed integer time_t. (Thanks to Paul Goyette for reporting
3746 typos in an experimental version of this change.)
3748 (Thanks to Philip Newton for correcting typos in these changes.)
3750 Documentation and commentary is more careful to distinguish UT in
3751 general from UTC in particular. (Thanks to Steve Allen.)
3753 Add a better source for the Zurich 1894 transition.
3754 (Thanks to Pierre-Yves Berger.)
3756 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
3759 Release 2013d - 2013-07-05 07:38:01 -0700
3761 Changes affecting future timestamps:
3763 Morocco's midsummer transitions this year are July 7 and August 10,
3764 not July 9 and August 8. (Thanks to Andrew Paprocki.)
3766 Israel now falls back on the last Sunday of October.
3767 (Thanks to Ephraim Silverberg.)
3769 Changes affecting past timestamps:
3771 Specify Jerusalem's location more precisely; this changes the pre-1880
3774 Changing affecting metadata only:
3776 Fix typos in the entries for country codes BQ and SX.
3778 Changes affecting code:
3780 Rework the code to fix a bug with handling Australia/Macquarie on
3781 32-bit hosts (thanks to Arthur David Olson).
3783 Port to platforms like NetBSD, where time_t can be wider than long.
3785 Add support for testing time_t types other than the system's.
3786 Run 'make check_time_t_alternatives' to try this out.
3787 Currently, the tests fail for unsigned time_t;
3788 this should get fixed at some point.
3790 Changes affecting documentation and commentary:
3792 Deemphasize the significance of national borders.
3794 Update the zdump man page.
3796 Remove obsolete NOID comment (thanks to Denis Excoffier).
3798 Update several URLs and comments in the web pages.
3800 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3802 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3805 Release 2013c - 2013-04-19 16:17:40 -0700
3807 Changes affecting current and future timestamps:
3809 Palestine observed DST starting March 29, 2013. (Thanks to
3810 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
3811 with the predicted rules being the last Thursday in March at 24:00
3812 to the first Friday on or after September 21 at 01:00.
3814 Assume that the recent change to Paraguay's DST rules is permanent,
3815 by moving the end of DST to the 4th Sunday in March every year.
3816 (Thanks to Carlos Raúl Perasso.)
3818 Changes affecting past timestamps:
3820 Fix some historical data for Palestine to agree with that of
3821 timeanddate.com, as follows:
3823 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3826 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3829 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3831 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
3833 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
3835 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
3837 Fix times of habitation for Macquarie to agree with the Tasmania
3838 Parks & Wildlife Service history, which indicates that permanent
3839 habitation was 1899-1919 and 1948 on.
3841 Changing affecting metadata only:
3843 Macquarie Island is politically part of Australia, not Antarctica.
3844 (Thanks to Tobias Conradi.)
3846 Sort Macquarie more-consistently with other parts of Australia.
3847 (Thanks to Tim Parenti.)
3850 Release 2013b - 2013-03-10 22:33:40 -0700
3852 Changes affecting current and future timestamps:
3854 Haiti uses US daylight-saving rules this year, and presumably future years.
3855 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
3857 Paraguay will end DST on March 24 this year.
3858 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
3860 Morocco does not observe DST during Ramadan;
3861 try to predict Ramadan in Morocco as best we can.
3862 (Thanks to Erik Homoet for the heads-up.)
3864 Changes affecting commentary:
3866 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
3867 Update URL for Solaris. Mention Internet RFC 6557.
3868 Update Internet RFCs 2445->5545, 2822->5322.
3869 Switch from FTP to HTTP for Internet RFCs.
3872 Release 2013a - 2013-02-27 09:20:35 -0800
3874 Change affecting binary data format:
3876 The zone offset at the end of version-2-format zone files is now
3877 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
3879 Changes affecting current and future timestamps:
3881 Chile's 2013 rules, and we guess rules for 2014 and later, will be
3882 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
3883 (Thanks to Steffen Thorsen and Robert Elz.)
3885 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
3886 (Thanks to Tobias Conradi and Arthur David Olson.)
3888 Many changes affect historical timestamps before 1940.
3889 These were deduced from: Milne J. Civil time. Geogr J. 1899
3890 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
3892 Changes affecting the code:
3894 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
3895 the data). (Thanks to Arthur David Olson.)
3897 Fix localtime bug when time_t is unsigned and data files were generated
3898 by a signed time_t system. (Thanks to Doug Bailey for reporting and
3899 to Arthur David Olson for fixing.)
3901 Allow the email address for bug reports to be set by the packager.
3902 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
3904 Update HTML checking to be compatible with Ubuntu 12.10.
3906 Check that files are a safe subset of ASCII. At some point we may
3907 relax this requirement to a safe subset of UTF-8. Without the
3908 check, some non-UTF-8 encodings were leaking into the distribution.
3912 Restore a comment about copyright notices that was inadvertently deleted.
3913 (Thanks to Arthur David Olson.)
3915 Improve the commentary about which districts observe what times
3916 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
3918 Add web page links to tz.js.
3920 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
3923 Release 2012j - 2012-11-12 18:34:49 -0800
3925 Libya moved to CET this weekend, but with DST planned next year.
3926 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3928 Signatures now have the extension .asc, not .sign, as that's more
3929 standard. (Thanks to Phil Pennock.)
3931 The output of 'zdump --version', and of 'zic --version', now
3932 uses a format that is more typical for --version.
3933 (Thanks to Joseph S. Myers.)
3935 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
3936 now uses tz@iana.org rather than the old elsie address.
3938 zic -v now complains about abbreviations that are less than 3
3939 or more than 6 characters, as per Posix. Formerly, it checked
3940 for abbreviations that were more than 3.
3942 'make public' no longer puts its temporary directory under /tmp,
3943 and uses the just-built zic rather than the system zic.
3945 Various fixes to documentation and commentary.
3948 Release 2012i - 2012-11-03 12:57:09 -0700
3950 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
3952 Linker flags can now be specified via LDFLAGS.
3953 AWK now defaults to 'awk', not 'nawk'.
3954 The shell in tzselect now defaults to /bin/bash, but this can
3955 be overridden by specifying KSHELL.
3956 The main web page now mentions the unofficial GitHub repository.
3957 (Thanks to Mike Frysinger.)
3959 Tarball signatures can now be built by running 'make signatures'.
3960 There are also new makefile rules 'tarballs', 'check_public', and
3961 separate makefile rules for each tarball and signature file.
3962 A few makefile rules are now more portable to strict POSIX.
3964 The main web page now lists the canonical IANA URL.
3967 Release 2012h - 2012-10-26 22:49:10 -0700
3969 Bahia no longer has DST. (Thanks to Kelley Cook.)
3971 Tocantins has DST. (Thanks to Rodrigo Severo.)
3973 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
3975 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
3979 More C modernization, except that at Arthur David Olson's suggestion
3980 the instances of 'register' were kept.
3983 Release 2012g - 2012-10-17 20:59:45 -0700
3985 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
3987 Palestine fall 2012. (Thanks to Steffen Thorsen.)
3991 To attack the version-number problem, this release ships the file
3992 'Makefile' (which contains the release number) in both the tzcode and
3993 the tzdata tarballs. The two Makefiles are identical, and should be
3994 identical in any matching pair of tarballs, so it shouldn't matter
3995 which order you extract the tarballs. Perhaps we can come up with a
3996 better version-number scheme at some point; this scheme does have the
3997 virtue of not adding more files.
4000 Release 2012f - 2012-09-12 23:17:03 -0700
4002 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4003 20 this year. (Thanks to Steffen Thorsen.)
4006 Release 2012e - 2012-08-02 20:44:55 -0700
4008 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4009 (Thanks to Steffen Thorsen.)
4011 * Use a single version number for both code and data.
4013 * .gitignore: New file.
4015 * Remove trailing white space.
4018 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4020 Changes for Morocco's timestamps, which take effect in a couple of
4021 hours, along with infrastructure changes to accommodate how the tz
4022 code and data are released on IANA.
4025 Release data2012c - 2012-03-27 12:17:25 -0400
4028 Summer time changes for Morocco (to start late April 2012)
4031 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4034 Haiti following US/Canada rules for 2012 (and we're assuming,
4035 for now anyway, for the future).
4038 Release 2012b - 2012-03-02 12:29:15 +0700
4040 There is just one change to tzcode2012b (compared with 2012a):
4041 the Makefile that was accidentally included with 2012a has been
4042 replaced with the version that should have been there, which is
4043 identical with the previous version (from tzcode2011i).
4045 There are just two changes in tzdata2012b compared with 2012a.
4047 Most significantly, summer time in Cuba has been delayed 3 weeks
4048 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4049 date, as listed in 2012a) is just a little over a week away, this
4052 Less importantly, an excess tab in one of the changes in zone.tab
4053 in 2012a has been removed.
4056 Release 2012a - 2012-03-01 18:28:10 +0700
4058 The changes in tzcode2012a (compared to the previous version, 2011i)
4059 are entirely to the README and tz-art.htm and tz-link.htm files, if
4060 none of those concern you, you can ignore the code update. The changes
4061 reflect the changed addresses for the mailing list and the code and
4062 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4063 has been added to tz-link.htm).
4065 In tzdata2012a (compared to the previous release, which was 2011n)
4066 the major changes are:
4067 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4068 Falkland Islands onto permanent summer time (we're assuming for the
4069 foreseeable future, though 2012 is all we're fairly certain of.)
4070 Armenia has abolished Summer Time.
4071 Tokelau jumped the International Date Line back last December
4072 (just the same as their near neighbour, Samoa).
4073 America/Creston is a new zone for a small area of British Columbia
4074 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4076 Other minor changes are:
4077 Corrections to 1918 Canadian summer time end dates.
4078 Updated URL for UK time zone history (in comments)
4079 A few typos in Le Corre's list of free French place names (comments)
4082 Release data2011n - 2011-10-30 14:57:54 +0700
4084 There are three changes of note - most urgently, Cuba (America/Havana)
4085 has extended summer time by two weeks, now to end on Nov 13, rather than
4086 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4087 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4088 all, and consequently that zone has been removed (again) and reinstated
4089 in the "backward" file as a link to Europe/Chisinau. And third, the
4090 end date for Fiji's summer time this summer was moved forward from the
4091 earlier planned Feb 26, to Jan 22.
4093 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4094 (and the incorrect syntax that was in the 2011m version of that file
4095 is so fixed - it would have been fixed in a different way had this
4096 change not happened - that's the "missing" sccs version id).
4099 Release data2011m - 2011-10-24 21:42:16 +0700
4101 In particular, the typos in comments in the data (2011-11-17 should have
4102 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4103 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4104 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
4105 Tim Parenti, and also Denys Gavrysh)
4107 In addition, I added Europe/Tiraspol to zone.tab.
4109 This time, all the files have new version numbers... (including the files
4110 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4111 version numbers there...)
4114 Release data2011l - 2011-10-10 11:15:43 +0700
4116 There are just 2 changes that cause different generated tzdata files from
4117 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4118 is included, but commented out. Compared with the diff I sent out last week,
4119 this version also includes attributions for the sources for the changes
4120 (in much the same format as ado used, but the html tags have not been
4121 checked, verified, or used in any way at all, so if there are errors there,
4122 please let me know.)
4125 Release data2011k - 2011-09-20 17:54:03 -0400
4130 Release data2011j - 2011-09-12 09:22:49 -0400
4132 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4133 Tanzania); there are also two spelling corrections to comments in
4134 the australasia file (with thanks to Christos Zoulas).
4137 Release 2011i - 2011-08-29 05:56:32 -0400
4142 Release data2011h - 2011-06-15 18:41:48 -0400
4144 Russia and Curaçao changes
4147 Release 2011g - 2011-04-25 09:07:22 -0400
4149 update the rules for Egypt to reflect its abandonment of DST this year
4152 Release 2011f - 2011-04-06 17:14:53 -0400
4157 Release 2011e - 2011-03-31 16:04:38 -0400
4159 Morocco, Chile, and tz-link changes
4162 Release 2011d - 2011-03-14 09:18:01 -0400
4164 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4167 Release 2011c - 2011-03-07 09:30:09 -0500
4169 These do affect current timestamps in Chile and Annette Island, Canada.
4172 Release 2011b - 2011-02-07 08:44:50 -0500
4177 Release 2011a - 2011-01-24 10:30:16 -0500
4182 Release data2010o - 2010-11-01 09:18:23 -0400
4184 change to the end of DST in Fiji in 2011
4187 Release 2010n - 2010-10-25 08:19:17 -0400
4192 Release 2010m - 2010-09-27 09:24:48 -0400
4194 Hong Kong, Vostok, and zic.c changes
4197 Release 2010l - 2010-08-16 06:57:25 -0400
4202 Release 2010k - 2010-07-26 10:42:27 -0400
4207 Release 2010j - 2010-05-10 09:07:48 -0400
4209 changes for Bahía de Banderas and for version naming
4212 Release data2010i - 2010-04-16 18:50:45 -0400
4214 the end of DST in Morocco on 2010-08-08
4217 Release data2010h - 2010-04-05 09:58:56 -0400
4222 Release data2010g - 2010-03-24 11:14:53 -0400
4227 Release 2010f - 2010-03-22 09:45:46 -0400
4232 Release data2010e - 2010-03-08 14:24:27 -0500
4234 corrects the Dhaka bug found by Danvin Ruangchan
4237 Release data2010d - 2010-03-06 07:26:01 -0500
4242 Release 2010c - 2010-03-01 09:20:58 -0500
4244 changes including KRE's suggestion for earlier initialization of
4245 "goahead" and "goback" structure elements
4248 Release code2010a - 2010-02-16 10:40:04 -0500
4253 Release data2010b - 2010-01-20 12:37:01 -0500
4258 Release data2010a - 2010-01-18 08:30:04 -0500
4263 Release data2009u - 2009-12-26 08:32:28 -0500
4265 changes to DST in Bangladesh
4268 Release 2009t - 2009-12-21 13:24:27 -0500
4273 Release data2009s - 2009-11-14 10:26:32 -0500
4275 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4278 Release 2009r - 2009-11-09 10:10:31 -0500
4280 "antarctica" and "tz-link.htm" changes
4283 Release 2009q - 2009-11-02 09:12:40 -0500
4285 with two corrections as reported by Eric Muller and Philip Newton
4288 Release data2009p - 2009-10-23 15:05:27 -0400
4290 Argentina (including San Luis) changes (with the correction from
4294 Release data2009o - 2009-10-14 16:49:38 -0400
4296 Samoa (commentary only), Pakistan, and Bangladesh changes
4299 Release data2009n - 2009-09-22 15:13:38 -0400
4301 added commentary for Argentina and a change to the end of DST in
4305 Release data2009m - 2009-09-03 10:23:43 -0400
4307 Samoa and Palestine changes
4310 Release data2009l - 2009-08-14 09:13:07 -0400
4312 Samoa (comments only) and Egypt
4315 Release 2009k - 2009-07-20 09:46:08 -0400
4320 Release data2009j - 2009-06-15 06:43:59 -0400
4322 Bangladesh change (with a short turnaround since the DST change is
4326 Release 2009i - 2009-06-08 09:21:22 -0400
4328 updating for DST in Bangladesh this year
4331 Release 2009h - 2009-05-26 09:19:14 -0400
4336 Release data2009g - 2009-04-20 16:34:07 -0400
4341 Release data2009f - 2009-04-10 11:00:52 -0400
4343 correct DST in Pakistan
4346 Release 2009e - 2009-04-06 09:08:11 -0400
4351 Release 2009d - 2009-03-23 09:38:12 -0400
4353 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4356 Release data2009c - 2009-03-16 09:47:51 -0400
4358 change to the start of Cuban DST
4361 Release 2009b - 2009-02-09 11:15:22 -0500
4366 Release 2009a - 2009-01-21 10:09:39 -0500
4371 Release data2008i - 2008-10-21 12:10:25 -0400
4373 southamerica and zone.tab files, with Argentina DST rule changes and
4374 United States zone reordering and recommenting
4377 Release 2008h - 2008-10-13 07:33:56 -0400
4382 Release 2008g - 2008-10-06 09:03:18 -0400
4384 Fix a broken HTML anchor and update Brazil's DST transitions;
4385 there's also a slight reordering of information in tz-art.htm.
4388 Release data2008f - 2008-09-09 22:33:26 -0400
4393 Release 2008e - 2008-07-28 14:11:17 -0400
4395 changes by Arthur David Olson and Jesper Nørgaard Welen
4398 Release data2008d - 2008-07-07 09:51:38 -0400
4400 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4403 Release data2008c - 2008-05-19 17:48:03 -0400
4405 Pakistan, Morocco, and Mongolia
4408 Release data2008b - 2008-03-24 08:30:59 -0400
4410 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4414 Release 2008a - 2008-03-08 05:42:16 -0500
4419 Release 2007k - 2007-12-31 10:25:22 -0500
4421 most importantly, changes to the "southamerica" file based on
4422 Argentina's readoption of daylight saving time
4425 Release 2007j - 2007-12-03 09:51:01 -0500
4427 1. eliminate the "P" (parameter) macro;
4429 2. the "noncontroversial" changes circulated on the time zone
4430 mailing list (less the changes to "logwtmp.c");
4432 3. eliminate "too many transition" errors when "min" is used in time
4435 4. changes by Paul Eggert (including updated information for Venezuela).
4438 Release data2007i - 2007-10-30 10:28:11 -0400
4440 changes for Cuba and Syria
4443 Release 2007h - 2007-10-01 10:05:51 -0400
4445 changes by Paul Eggert, as well as an updated link to the ICU
4446 project in tz-link.htm
4449 Release 2007g - 2007-08-20 10:47:59 -0400
4451 changes by Paul Eggert
4453 The "leapseconds" file has been updated to incorporate the most
4454 recent International Earth Rotation and Reference Systems Service
4457 There's an addition to tz-art.htm regarding the television show "Medium".
4460 Release 2007f - 2007-05-07 10:46:46 -0400
4462 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4465 changes to zic.c to allow hour values greater than 24 (along with
4466 Paul's improved time value overflow checking)
4469 Release 2007e - 2007-04-02 10:11:52 -0400
4471 Syria and Honduras changes by Paul Eggert
4473 zic.c variable renaming changes by Arthur David Olson
4476 Release 2007d - 2007-03-20 08:48:30 -0400
4478 changes by Paul Eggert
4480 the elimination of white space at the ends of lines
4483 Release 2007c - 2007-02-26 09:09:37 -0500
4485 changes by Paul Eggert
4488 Release 2007b - 2007-02-12 09:34:20 -0500
4490 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4492 changes to the commentary in "leapseconds" reflecting the IERS
4493 announcement that there is to be no positive leap second at the end
4497 Release 2007a - 2007-01-08 12:28:29 -0500
4499 changes by Paul Eggert
4501 Derick Rethans's Asmara change
4503 Oscar van Vlijmen's Easter Island local mean time change
4505 symbolic link changes
4508 Release 2006p - 2006-11-27 08:54:27 -0500
4510 changes by Paul Eggert
4513 Release 2006o - 2006-11-06 09:18:07 -0500
4515 changes by Paul Eggert
4518 Release 2006n - 2006-10-10 11:32:06 -0400
4520 changes by Paul Eggert
4523 Release 2006m - 2006-10-02 15:32:35 -0400
4525 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4527 (minimalist) changes to zic.8 to clarify "until" information
4530 Release data2006l - 2006-09-18 12:58:11 -0400
4532 Paul's best-effort work on this coming weekend's Egypt time change
4535 Release 2006k - 2006-08-28 12:19:09 -0400
4537 changes by Paul Eggert
4540 Release 2006j - 2006-08-21 09:56:32 -0400
4542 changes by Paul Eggert
4545 Release code2006i - 2006-08-07 12:30:55 -0400
4549 Ken Pizzini's conversion script
4552 Release code2006h - 2006-07-24 09:19:37 -0400
4554 adds public domain notices to four files
4556 includes a fix for transition times being off by a second
4558 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4561 Release 2006g - 2006-05-08 17:18:09 -0400
4563 northamerica changes by Paul Eggert
4566 Release 2006f - 2006-05-01 11:46:00 -0400
4568 a missing version number problem is fixed (with thanks to Bradley
4569 White for catching the problem)
4572 Release 2006d - 2006-04-17 14:33:43 -0400
4574 changes by Paul Eggert
4576 added new items to tz-arts.htm that were found by Paul
4579 Release 2006c - 2006-04-03 10:09:32 -0400
4581 two sets of data changes by Paul Eggert
4583 a fencepost error fix in zic.c
4585 changes to zic.c and the "europe" file to minimize differences
4586 between output produced by the old 32-bit zic and the new 64-bit
4590 Release 2006b - 2006-02-20 10:08:18 -0500
4591 [tz32code2006b + tz64code2006b + tzdata2006b]
4595 All SCCS IDs were bumped to "8.1" for this release.
4598 Release 2006a - 2006-01-30 08:59:31 -0500
4600 changes by Paul Eggert (in particular, Indiana time zone moves)
4602 an addition to the zic manual page to describe how special-case
4603 transitions are handled
4606 Release 2005r - 2005-12-27 09:27:13 -0500
4608 Canadian changes by Paul Eggert
4610 They also add "<pre>" directives to time zone data files and reflect
4611 changes to warning message logic in "zdump.c" (but with calls to
4612 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4615 Release 2005q - 2005-12-13 09:17:09 -0500
4617 Nothing earth-shaking here:
4618 1. Electronic mail addresses have been removed.
4619 2. Casts of the return value of exit have been removed.
4620 3. Casts of the argument of is.* macros have been added.
4621 4. Indentation in one section of zic.c has been fixed.
4622 5. References to dead URLs in the data files have been dealt with.
4625 Release 2005p - 2005-12-05 10:30:53 -0500
4627 "systemv", "tz-link.htm", and "zdump.c" changes
4628 (less the casts of arguments to the is* macros)
4631 Release 2005o - 2005-11-28 10:55:26 -0500
4633 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4635 zdump.c lint fixes by Arthur David Olson
4638 Release 2005n - 2005-10-03 09:44:09 -0400
4640 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4644 Release 2005m - 2005-08-29 12:15:40 -0400
4646 changes by Paul Eggert (with a small tweak to the tz-art change)
4648 a declaration of an unused variable has been removed from zdump.c
4651 Release 2005l - 2005-08-22 12:06:39 -0400
4653 changes by Paul Eggert
4655 overflow/underflow checks by Arthur David Olson, minus changes to
4656 the "Theory" file about the pending addition of 64-bit data (I grow
4657 less confident of the changes being accepted with each passing day,
4658 and the changes no longer increase the data files nine-fold--there's
4659 less than a doubling in size by my local Sun's reckoning)
4662 Release 2005k - 2005-07-14 14:14:24 -0400
4664 The "leapseconds" file has been edited to reflect the recently
4665 announced leap second at the end of 2005.
4667 I've also deleted electronic mail addresses from the files as an
4671 Release 2005j - 2005-06-13 14:34:13 -0400
4673 These reflect changes to limit the length of time zone abbreviations
4674 and the characters used in those abbreviations.
4676 There are also changes to handle POSIX-style "quoted" timezone
4677 environment variables.
4679 The changes were circulated on the time zone mailing list; the only
4680 change since then was the removal of a couple of minimum-length of
4681 abbreviation checks.
4684 Release data2005i - 2005-04-21 15:04:16 -0400
4686 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4689 Release 2005h - 2005-04-04 11:24:47 -0400
4691 changes by Paul Eggert
4693 minor changes to Makefile and zdump.c to produce more useful output
4694 when doing a "make typecheck"
4697 Release 2005g - 2005-03-14 10:11:21 -0500
4699 changes by Paul Eggert (a change to current DST rules in Uruguay and
4700 an update to a link to time zone software)
4703 Release 2005f - 2005-03-01 08:45:32 -0500
4705 data and documentation changes by Paul Eggert
4708 Release 2005e - 2005-02-10 15:59:44 -0500
4713 Release code2005d - 2005-01-31 09:21:47 -0500
4715 make zic complain about links to links if the -v flag is used
4717 have "make public" do more code checking
4719 add an include to "localtime.c" for the benefit of gcc systems
4722 Release 2005c - 2005-01-17 18:36:29 -0500
4724 get better results when mktime runs on a system where time_t is double
4726 changes to the data files (most importantly to Paraguay)
4729 Release 2005b - 2005-01-10 09:19:54 -0500
4731 Get localtime and gmtime working on systems with exotic time_t types.
4733 Update the leap second commentary in the "leapseconds" file.
4736 Release 2005a - 2005-01-01 13:13:44 -0500
4741 Release code2004i - 2004-12-14 13:42:58 -0500
4743 Deal with systems where time_t is unsigned.
4746 Release code2004h - 2004-12-07 11:40:18 -0500
4748 64-bit-time_t changes
4751 Release 2004g - 2004-11-02 09:06:01 -0500
4753 update to Cuba (taking effect this weekend)
4755 other changes by Paul Eggert
4757 correction of the spelling of Oslo
4759 changed versions of difftime.c and private.h
4762 Release code2004f - 2004-10-21 10:25:22 -0400
4764 Cope with wide-ranging tm_year values.
4767 Release 2004e - 2004-10-11 14:47:21 -0400
4769 Brazil/Argentina/Israel changes by Paul Eggert
4771 changes to tz-link.htm by Paul
4773 one small fix to Makefile
4776 Release 2004d - 2004-09-22 08:27:29 -0400
4778 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4781 Release 2004c - 2004-08-11 12:06:26 -0400
4783 asctime-related changes
4785 (variants of) some of the documentation changes suggested by Paul Eggert
4788 Release 2004b - 2004-07-19 14:33:35 -0400
4790 data changes by Paul Eggert - most importantly, updates for Argentina
4793 Release 2004a - 2004-05-27 12:00:47 -0400
4795 changes by Paul Eggert
4797 Handle DST transitions that occur at the end of a month in some
4798 years but at the start of the following month in other years.
4800 Add a copy of the correspondence that's the basis for claims about
4801 DST in the Navajo Nation.
4804 Release 2003e - 2003-12-15 09:36:47 -0500
4806 changes by Arthur David Olson (primarily code changes)
4808 changes by Paul Eggert (primarily data changes)
4810 minor changes to "Makefile" and "northamerica" (in the latter case,
4811 optimization of the "Toronto" rules)
4814 Release 2003d - 2003-10-06 09:34:44 -0400
4816 changes by Paul Eggert
4819 Release 2003c - 2003-09-16 10:47:05 -0400
4821 Fix bad returns in zic.c's inleap function.
4822 Thanks to Bradley White for catching the problem!
4825 Release 2003b - 2003-09-16 07:13:44 -0400
4827 Add a "--version" option (and documentation) to the zic and zdump commands.
4829 changes to overflow/underflow checking in zic
4831 a localtime typo fix.
4833 Update the leapseconds and tz-art.htm files.
4836 Release 2003a - 2003-03-24 09:30:54 -0500
4838 changes by Paul Eggert
4840 a few additions and modifications to the tz-art.htm file
4843 Release 2002d - 2002-10-15 13:12:42 -0400
4845 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
4847 There's also a new time zone quote in "tz-art.htm".
4850 Release 2002c - 2002-04-04 11:55:20 -0500
4852 changes by Paul Eggert
4854 Change zic.c to avoid creating symlinks to files that don't exist.
4857 Release 2002b - 2002-01-28 12:56:03 -0500
4859 [These change notes are for Release 2002a, which was corrupted.
4860 2002b was a corrected version of 2002a.]
4862 changes by Paul Eggert
4864 Update the "leapseconds" file to note that there'll be no leap
4865 second at the end of June, 2002.
4867 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
4869 Change to "difftime.c" to avoid sizeof problems.
4872 Release 2001d - 2001-10-09 13:31:32 -0400
4874 changes by Paul Eggert
4877 Release 2001c - 2001-06-05 13:59:55 -0400
4879 changes by Paul Eggert and Andrew Brown
4882 Release 2001b - 2001-04-05 16:44:38 -0400
4884 changes by Paul Eggert (modulo jnorgard's typo fix)
4886 tz-art.htm has been HTMLified.
4889 Release 2001a - 2001-03-13 12:57:44 -0500
4891 changes by Paul Eggert
4893 An addition to the "leapseconds" file: comments with the text of the
4894 latest IERS leap second notice.
4896 Trailing white space has been removed from data file lines, and
4897 repeated spaces in "Rule Jordan" lines in the "asia" file have been
4901 Release 2000h - 2000-12-14 15:33:38 -0500
4903 changes by Paul Eggert
4905 one typo fix in the "art" file
4907 With providence, this is the last update of the millennium.
4910 Release 2000g - 2000-10-10 11:35:22 -0400
4912 changes by Paul Eggert
4914 correction of John Mackin's name submitted by Robert Elz
4916 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
4917 Emmy Awards broadcast.
4920 Release 2000f - 2000-08-10 09:31:58 -0400
4922 changes by Paul Eggert
4924 Added information in "tz-art.htm" on a Seinfeld reference to DST.
4926 Error checking and messages in the "yearistype" script have been
4930 Release 2000e - 2000-07-31 09:27:54 -0400
4932 data changes by Paul Eggert
4934 a change to the default value of the defined constant HAVE_STRERROR
4936 the addition of a Dave Barry quote on DST to the tz-arts file
4939 Release 2000d - 2000-04-20 15:43:04 -0400
4941 changes to the documentation and code of strftime for C99 conformance
4943 a bug fix for date.c
4945 These are based on (though modified from) changes by Paul Eggert.
4948 Release 2000c - 2000-03-04 10:31:43 -0500
4950 changes by Paul Eggert
4953 Release 2000b - 2000-02-21 12:16:29 -0500
4955 changes by Paul Eggert and Joseph Myers
4957 modest tweaks to the tz-art.htm and tz-link.htm files
4960 Release 2000a - 2000-01-18 09:21:26 -0500
4962 changes by Paul Eggert
4964 The two hypertext documents have also been renamed.
4967 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
4969 Paul Eggert's changes
4971 additions to the "zic" manual page and the "Arts.htm" file
4974 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
4979 Release data1999h - 1999-10-07 03:50:29 -0400
4981 changes by Paul Eggert to "europe" (most importantly, fixing
4982 Lithuania and Estonia)
4985 Release 1999g - 1999-09-28 11:06:18 -0400
4987 data changes by Paul Eggert (most importantly, the change for
4988 Lebanon that buys correctness for this coming Sunday)
4990 The "code" file contains changes to "Makefile" and "checktab.awk" to
4991 allow better checking of time zone files before they are published.
4994 Release 1999f - 1999-09-23 09:48:14 -0400
4996 changes by Arthur David Olson and Paul Eggert
4999 Release 1999e - 1999-08-17 15:20:54 -0400
5001 changes circulated by Paul Eggert, although the change to handling
5002 of DST-specifying timezone names has been commented out for now
5003 (search for "XXX" in "localtime.c" for details). These files also
5004 do not make any changes to the start of DST in Brazil.
5006 In addition to Paul's changes, there are updates to "Arts.htm" and
5010 Release 1999d - 1999-03-30 11:31:07 -0500
5012 changes by Paul Eggert
5014 The Makefile's "make public" rule has also been changed to do a test
5015 compile of each individual time zone data file (which should help
5016 avoid problems such as the one we had with Nicosia).
5019 Release 1999c - 1999-03-25 09:47:47 -0500
5021 changes by Paul Eggert, most importantly the change for Chile.
5024 Release 1999b - 1999-02-01 17:51:44 -0500
5026 changes by Paul Eggert
5028 code changes (suggested by Mani Varadarajan, mani at be.com) for
5029 correct handling of symbolic links when building using a relative directory
5031 code changes to generate correct messages for failed links
5033 updates to the URLs in Arts.htm
5036 Release 1999a - 1999-01-19 16:20:29 -0500
5038 error message internationalizations and corrections in zic.c and
5039 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5043 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5045 changes for Brazil, Chile, and Germany
5047 support for use of "24:00" in the input files for the time zone compiler
5050 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5052 changes by Paul Eggert
5054 correction to a define in the "private.h" file
5057 Release data1998g - 1998-08-11 03:28:35 -0000
5058 [tzdata1998g.tar.gz is missing!]
5060 Lithuanian change provided by mgedmin at pub.osf.it
5062 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5063 "backward") to ensure that the GMT file is created even where folks
5064 don't want the "backward" links (as suggested by Paul Eggert).
5067 Release data1998f - 1998-07-20 13:50:00 -0000
5068 [tzdata1998f.tar.gz is missing!]
5070 Update the "leapseconds" file to include the newly-announced
5071 insertion at the end of 1998.
5074 Release code1998f - 1998-06-01 10:18:31 -0400
5076 addition to localtime.c by Guy Harris
5079 Release 1998e - 1998-05-28 09:56:26 -0400
5081 The Makefile is changed to produce zoneinfo-posix rather than
5082 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5085 data changes by Paul Eggert
5087 changes from Guy Harris to provide asctime_r and ctime_r
5089 A usno1998 file (substantially identical to usno1997) has been added.
5092 Release 1998d - 1998-05-14 11:58:34 -0400
5094 changes to comments (in particular, elimination of references to CIA maps).
5095 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5096 where changes occur.
5099 Release 1998c - 1998-02-28 12:32:26 -0500
5101 changes by Paul Eggert (save the "French correction," on which I'll
5102 wait for the dust to settle)
5106 changes and additions to Arts.htm
5109 Release 1998b - 1998-01-17 14:31:51 -0500
5111 URL cleanups and additions
5114 Release 1998a - 1998-01-13 12:37:35 -0500
5116 changes by Paul Eggert
5119 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5121 changes by Paul Eggert, with minor modifications from Arthur David
5122 Olson to make the files more browser friendly
5125 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5127 minor changes to put "TZif" at the start of each timezone information file
5129 a rule has also been added to the Makefile so you can
5131 to just recompile the zone information files (rather than doing a
5132 full "make install" with its other effects).
5135 Release data1997i - 1997-10-07 08:45:38 -0400
5137 changes to Africa by Paul Eggert
5140 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5142 corrections for Uruguay (and other locations)
5144 Arthur David Olson's simple-minded fix allowing mktime to both
5145 correctly handle leap seconds and correctly handle tm_sec values
5146 upon which arithmetic has been performed.
5149 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5151 Paul Eggert's updates
5153 a small change to a function prototype;
5155 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5156 include information on Around the World in Eighty Days.
5159 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5161 fixes to zic's error handling
5163 changes inspired by the item circulated on Slovenia
5165 The description of Web resources has been HTMLified for browsing
5168 A new piece of tz-related music has been added to the "Music" file.
5171 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5173 Paul Eggert's latest suggestions
5176 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5178 changes to "zic.c" to correct performance of the "-s" option
5180 a new file "usno1997"
5183 Release data1997c - 1997-03-04 09:58:18 -0500
5188 Release 1997b - 1997-02-27 18:34:19 -0500
5190 The data file incorporates the 1997 leap second.
5192 The code file incorporates Arthur David Olson's take on the
5193 zic/multiprocessor/directory-creation situation.
5196 Release 1997a - 1997-01-21 09:11:10 -0500
5198 Paul Eggert's Antarctica (and other changes)
5200 Arthur David Olson finessed the "getopt" issue by checking against
5201 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5202 is returned while SunOS 5.5's manual says EOF is returned).
5205 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5207 Paul Eggert's latest changes
5210 Release code1996n - 1996-12-16 09:42:02 -0500
5212 link snapping fix from Bruce Evans (via Garrett Wollman)
5215 Release data1996m - 1996-11-24 02:37:34 -0000
5216 [tzdata1996m.tar.gz is missing!]
5218 Paul Eggert's batch of changes
5221 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5223 No functional changes here; the files have simply been changed to
5224 make more use of ISO style dates in comments. The names of the above
5225 files now include the year in full.
5228 Release code96l - 1996-09-08 17:12:20 -0400
5230 tzcode96k was missing a couple of pieces.
5233 Release 96k - 1996-09-08 16:06:22 -0400
5235 the latest round of changes from Paul Eggert
5237 the recent Year 2000 material
5240 Release code96j - 1996-07-30 13:18:53 -0400
5242 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5245 Release code96i - 1996-07-27 20:11:35 -0400
5247 Paul's suggested patch for strftime %V week numbers
5250 Release data96i - 1996-07-01 18:13:04 -0400
5252 "northamerica" and "europe" changes by Paul Eggert
5255 Release code96h - 1996-06-05 08:02:21 -0400
5257 fix for handling transitions specified in Universal Time
5259 Some "public domain" notices have also been added.
5262 Release code96g - 1996-05-16 14:00:26 -0400
5264 fix for the simultaneous-DST-and-zone-change challenge
5267 Release data96h - 1996-05-09 17:40:51 -0400
5269 changes by Paul Eggert
5272 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5273 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5275 The changes get us some of the way to fixing the problems noted in Paul
5276 Eggert's letter yesterday (in addition to a few others). The approach
5277 has been to make zic a bit smarter about figuring out what time zone
5278 abbreviations apply just after the time specified in the "UNTIL" part
5279 of a zone line. Putting the smarts in zic means avoiding having
5280 transition times show up in both "Zone" lines and "Rule" lines, which
5281 in turn avoids multiple transition time entries in time zone files.
5282 (This also makes the zic input files such as "europe" a bit shorter and
5283 should ease maintenance.)
5286 Release data96f - 1996-04-19 19:20:03 -0000
5287 [tzdata96f.tar.gz is missing!]
5289 The only changes are to the "northamerica" file; the time zone
5290 abbreviation for Denver is corrected to MST (and MDT), and the
5291 comments for Mexico have been updated.
5294 Release data96e - 1996-03-19 17:37:26 -0500
5296 Proposals by Paul Eggert, in particular the Portugal change that
5297 comes into play at the end of this month.
5300 Release data96d - 1996-03-18 20:49:39 -0500
5305 Release code96e - 1996-02-29 15:43:27 -0000
5306 [tzcode96e.tar.gz is missing!]
5308 internationalization changes and the fix to the documentation for strftime
5311 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5313 The "code" file simply updates Bob Kridle's electronic address.
5315 The "data" file updates rules for Mexico.
5318 Release data96b - 1996-01-27 15:44:42 -0500
5323 Release code96c - 1996-01-16 16:58:15 -0500
5325 leap-year streamlining and binary-search changes
5330 Release code96b - 1996-01-10 20:42:39 -0500
5332 fixes and enhancements from Paul Eggert, including code that
5333 emulates the behavior of recent versions of the SunOS "date"
5337 Release 96a - 1996-01-06 09:08:24 -0500
5341 fixes to strftime.c for correct ISO 8601 week number generation,
5342 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5343 numbers (which are not necessarily the same as calendar year numbers)
5346 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5348 The latest revisions from Paul Eggert are included, the usno1995
5349 file has been updated, and a new file ("WWW") covering useful URLs
5353 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5355 A simplification of a macro definition, a change to data for Sudan,
5356 and (for last minute shoppers) notes in the "Music" file on the CD
5360 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5362 (slightly reformatted) 8-bit-clean proposed patch
5364 minor patch: US/Eastern -> America/New_York
5366 snapshot of the USNO's latest data ("usno1995")
5368 some other minor cleanups
5371 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5372 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5376 support for 64-bit time_t's
5378 optimization in localtime.c
5381 Release code95e - 1995-10-13 13:23:57 -0400
5383 the mktime change to scan from future to past when trying to find time zone
5387 Release data95i - 1995-09-26 10:43:26 -0400
5389 For Canada/Central, guess that the Sun customer's "one week too
5390 early" was just a approximation, and the true error is one month
5391 too early. This is consistent with the rest of Canada.
5394 Release data95h - 1995-09-21 11:26:48 -0400
5396 latest changes from Paul Eggert
5399 Release code95d - 1995-09-14 11:14:45 -0400
5401 the addition of a "Music" file, which documents four recorded
5402 versions of the tune "Save That Time".
5405 Release data95g - 1995-09-01 17:21:36 -0400
5407 "yearistype" correction
5410 Release data95f - 1995-08-28 20:46:56 -0400
5412 Paul Eggert's change to the australasia file
5415 Release data95e - 1995-07-08 18:02:34 -0400
5417 The only change is a leap second at the end of this year.
5418 Thanks to Bradley White for forwarding news on the leap second.
5421 Release data95d - 1995-07-03 13:26:22 -0400
5423 Paul Eggert's changes
5426 Release data95c - 1995-07-02 19:19:28 -0400
5428 changes to "asia", "backward", "europe", and "southamerica"
5429 (read: northamericacentrics need not apply)
5432 Release code95c - 1995-03-13 14:00:46 -0500
5434 one-line fix for sign extension problems in detzcode
5437 Release 95b - 1995-03-04 11:22:38 -0500
5439 Minor changes in both:
5441 The "code" file contains a workaround for the lack of "unistd.h" in
5442 Microsoft C++ version 7.
5444 The "data" file contains a fixed "Link" for America/Shiprock.
5447 Release 94h - 1994-12-10 12:51:14 -0500
5451 * incorporate the changes to "zdump" and "date" to make changes to
5452 the "TZ" environment variable permanent;
5454 * incorporate the table changes by Paul Eggert;
5456 * include (and document) support for universal time specifications in
5457 data files - but do not (yet) include use of this feature in the
5460 Think of this as "TZ Classic" - the software has been set up not to break if
5461 universal time shows up in its input, and data entries have been
5462 left as is so as not to break existing implementations.
5465 Release data94f - 1994-08-20 12:56:09 -0400
5467 (with thanks!) the latest data updates from Paul Eggert
5470 Release data94e - 1994-06-04 13:13:53 -0400
5475 Release code94g - 1994-05-05 12:14:07 -0400
5477 fix missing "optind.c" and a reference to it in the Makefile
5480 Release code94f - 1994-05-05 13:00:33 -0000
5481 [tzcode94f.tar.gz is missing!]
5483 changes to avoid overflow in difftime, as well as changes to cope
5484 with the 52/53 challenge in strftime
5487 Release code94e - 1994-03-30 23:32:59 -0500
5489 change for the benefit of PCTS
5492 Release 94d - 1994-02-24 15:42:25 -0500
5494 Avoid clashes with POSIX semantics for zones such as GMT+4.
5496 Some other very minor housekeeping is also present.
5499 Release code94c - 1994-02-10 08:52:40 -0500
5501 Fix bug where mkdirs was broken unless you compile with
5502 -fwritable-strings (which is generally losing to do).
5505 Release 94b - 1994-02-07 10:04:33 -0500
5507 work by Paul Eggert who notes:
5509 I found another book of time zone histories by E W Whitman; it's not
5510 as extensive as Shanks but has a few goodies of its own. I used it
5511 to update the tables. I also fixed some more as a result of
5512 correspondence with Adam David and Peter Ilieve, and move some stray
5513 links from 'europe' to 'backward'. I corrected some scanning errors
5516 As far as the code goes, I fixed zic to allow years in the range
5517 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5518 And I cleaned up the zic documentation a little bit.
5521 Release data94a - 1994-02-03 08:58:54 -0500
5523 It simply incorporates the recently announced leap second into the
5527 Release 93g - 1993-11-22 17:28:27 -0500
5529 Paul Eggert has provided a good deal of historic information (based
5530 on Shanks), and there are some code changes to deal with the buglets
5531 that crawled out in dealing with the new information.
5534 Release 93f - 1993-10-15 12:27:46 -0400
5536 Paul Eggert's changes
5539 Release 93e - 1993-09-05 21:21:44 -0400
5541 This has updated data for Israel, England, and Kwajalein. There's
5542 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5543 Thanks to Paul Eggert and Peter Ilieve for the changes.
5546 Release 93d - 1993-06-17 23:34:17 -0400
5548 new fix and new data on Israel
5551 Release 93c - 1993-06-06 19:31:55 -0400
5556 Release 93b - 1993-02-02 14:53:58 -0500
5558 updated "leapseconds" file
5561 Release 93 - 1993-01-08 07:01:06 -0500
5563 At kre's suggestion, the package has been split in two - a code piece
5564 (which also includes documentation) that's only of use to folks who
5565 want to recompile things and a data piece useful to anyone who can
5568 The new version has a few changes to the data files, a few
5569 portability changes, and an off-by-one fix (with thanks to
5570 Tom Karzes at deshaw.com for providing a description and a
5574 Release 92c - 1992-11-21 17:35:36 -0000
5575 [tz92c.tar.Z is missing!]
5577 The fallout from the latest round of DST transitions.
5579 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5580 there's also a change to "zic.c" that makes it portable to more systems.
5583 Release 92 - 1992-04-25 18:17:03 -0000
5584 [tz92.tar.Z is missing!]
5586 By popular demand (well, at any rate, following a request by kre at munnari)
5589 The 1989 update of the time zone package featured:
5591 * POSIXization (including interpretation of POSIX-style TZ environment
5592 variables, provided by Guy Harris),
5593 * ANSIfication (including versions of "mktime" and "difftime"),
5594 * SVIDulation (an "altzone" variable)
5595 * MACHination (the "gtime" function)
5596 * corrections to some time zone data (including corrections to the rules
5597 for Great Britain and New Zealand)
5598 * reference data from the United States Naval Observatory for folks who
5599 want to do additional time zones
5600 * and the 1989 data for Saudi Arabia.
5602 (Since this code will be treated as "part of the implementation" in some
5603 places and as "part of the application" in others, there's no good way to
5604 name functions, such as timegm, that are not part of the proposed ANSI C
5605 standard; such functions have kept their old, underscore-free names in this
5608 And the "dysize" function has disappeared; it was present to allow
5609 compilation of the "date" command on old BSD systems, and a version of "date"
5610 is now provided in the package. The "date" command is not created when you
5611 "make all" since it may lack options provided by the version distributed with
5612 your operating system, or may not interact with the system in the same way
5613 the native version does.
5615 Since POSIX frowns on correct leap second handling, the default behavior of
5616 the "zic" command (in the absence of a "-L" option) has been changed to omit
5617 leap second information from its output files.
5623 This file contains copies of the part of each release announcement
5624 that talks about the changes in that release. The text has been
5625 adapted and reformatted for the purposes of this file.
5627 Traditionally a release R consists of a pair of tarball files,
5628 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5629 code2010a, data2012c) consist of just one or the other tarball, and a
5630 few (e.g., code2012c-data2012d) have tarballs with mixed version
5631 numbers. Recent releases also come in an experimental format
5632 consisting of a single tarball tzdb-R.tar.lz with extra data.
5634 Release timestamps are taken from the release's commit (for newer,
5635 Git-based releases), from the newest file in the tarball (for older
5636 releases, where this info is available) or from the email announcing
5637 the release (if all else fails; these are marked with a time zone
5638 abbreviation of -0000 and an "is missing!" comment).
5640 Earlier versions of the code and data were not announced on the tz
5641 list and are not summarized here.
5643 This file is in the public domain.