1 News for the tz database
3 Release 2022c - 2022-08-15 17:47:18 -0700
6 Work around awk bug in FreeBSD, macOS, etc.
7 Improve tzselect on intercontinental Zones.
11 Work around a bug in onetrueawk that broke commands like
12 'make traditional_tarballs' on FreeBSD, macOS, etc.
13 (Problem reported by Deborah Goldsmith.)
15 Add code to tzselect that uses experimental structured comments in
16 zone1970.tab to clarify whether Zones like Africa/Abidjan and
17 Europe/Istanbul cross continent or ocean boundaries.
18 (Inspired by a problem reported by Peter Krefting.)
20 Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
21 directory /a/b already exists.
23 Remove zoneinfo2tdf.pl, as it was unused and triggered false
24 malware alarms on some email servers.
27 Release 2022b - 2022-08-10 15:38:32 -0700
30 Chile's DST is delayed by a week in September 2022.
31 Iran no longer observes DST after 2022.
32 Rename Europe/Kiev to Europe/Kyiv.
34 Vanguard form now uses %z.
35 Finish moving duplicate-since-1970 zones to 'backzone'.
36 New build option PACKRATLIST
37 New tailored_tarballs target, replacing rearguard_tarballs
39 Changes to future timestamps
41 Chile's 2022 DST start is delayed from September 4 to September 11.
42 (Thanks to Juan Correa.)
44 Iran plans to stop observing DST permanently, after it falls back
45 on 2022-09-21. (Thanks to Ali Mirjamali.)
47 Changes to past timestamps
49 Finish moving to 'backzone' the location-based zones whose
50 timestamps since 1970 are duplicates; adjust links accordingly.
51 This change ordinarily affects only pre-1970 timestamps, and with
52 the new PACKRATLIST option it does not affect any timestamps.
53 In this round the affected zones are Antarctica/Vostok,
54 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
55 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
56 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
57 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
58 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
59 Pacific/Wake and Pacific/Wallis, and the affected links are
60 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
61 Pacific/Truk, and Pacific/Yap.
63 From fall 1994 through fall 1995, Shanks wrote that Crimea's
64 DST transitions were at 02:00 standard time, not at 00:00.
65 (Thanks to Michael Deckers.)
67 Iran adopted standard time in 1935, not 1946. In 1977 it observed
68 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
69 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
70 transition was on 05-27, not 03-21.
71 (Thanks to Roozbeh Pournader and Francis Santoni.)
73 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
74 considered DST, not standard time. Santiago and environs had moved
75 their clocks back to rejoin the rest of mainland Chile; put this
76 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
78 Some old, small clock transitions have been removed, as people at
79 the time did not change their clocks. This affects Asia/Hong_Kong
80 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
84 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
85 English now. Spelling of other names in Ukraine has not yet
86 demonstrably changed in common English practice so for now these
87 names retain old spellings, as in other countries (e.g.,
88 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
92 zic has a new option '-R @N' to output explicit transitions < N.
93 (Need suggested by Almaz Mingaleev.)
95 'zic -r @N' no longer outputs bad data when N < first transition.
96 (Problem introduced in 2021d and reported by Peter Krefting.)
98 zic now checks its input for NUL bytes and unterminated lines, and
99 now supports input line lengths up to 2048 (not 512) bytes.
101 gmtime and related code now use the abbreviation "UTC" not "GMT".
102 POSIX is being revised to require this.
104 When tzset and related functions set vestigial static variables
105 like tzname, they now prefer specified timestamps to unspecified ones.
106 (Problem reported by Almaz Mingaleev.)
108 zic no longer complains "can't determine time zone abbreviation to
109 use just after until time" when a transition to a new standard
110 time occurs simultaneously with the first DST fallback transition.
112 Changes to build procedure
114 Source data in vanguard form now uses the %z notation, introduced
115 in release 2015f. For example, for America/Sao_Paulo vanguard
116 form contains the zone continuation line "-3:00 Brazil %z", which
117 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
118 used in main and rearguard forms. The plan is for the main form
119 to use %z eventually; in the meantime maintainers of zi parsers
120 are encouraged to test the parsers on vanguard.zi.
122 The Makefile has a new PACKRATLIST option to select a subset of
123 'backzone'. For example, 'make PACKRATDATA=backzone
124 PACKRATLIST=zone.tab' now generates TZif files identical to those
125 of the global-tz project.
127 The Makefile has a new tailored_tarballs target for generating
128 special-purpose tarballs. It generalizes and replaces the
129 rearguard_tarballs target and related targets and macros, which
132 'make install' now defaults LOCALTIME to Factory not GMT,
133 which means the default abbreviation is now "-00" not "GMT".
135 Remove the posix_packrat target, marked obsolescent in 2016a.
138 Release 2022a - 2022-03-15 23:02:01 -0700
141 Palestine will spring forward on 2022-03-27, not -03-26.
142 zdump -v now outputs better failure indications.
143 Bug fixes for code that reads corrupted TZif data.
145 Changes to future timestamps
147 Palestine will spring forward on 2022-03-27, not 2022-03-26.
148 (Thanks to Heba Hamad.) Predict future transitions for first
149 Sunday >= March 25. Additionally, predict fallbacks to be the first
150 Friday on or after October 23, not October's last Friday, to be more
151 consistent with recent practice. The first differing fallback
152 prediction is on 2025-10-24, not 2025-10-31.
154 Changes to past timestamps
156 From 1992 through spring 1996, Ukraine's DST transitions were at
157 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
159 Chile's Santiago Mean Time and its LMT precursor have been adjusted
160 eastward by 1 second to align with past and present law.
162 Changes to commentary
164 Add several references for Chile's 1946/1947 transitions, some of
165 which only affected portions of the country.
169 Fix bug when mktime gets confused by truncated TZif files with
170 unspecified local time. (Problem reported by Almaz Mingaleev.)
172 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
173 (Problem reported by Christos Zoulas.)
175 When reading a version 2 or later TZif file, the TZif reader now
176 validates the version 1 header and data block only enough to skip
177 over them, as recommended by RFC 8536 section 4. Also, the TZif
178 reader no longer mistakenly attempts to parse a version 1 TZIf
179 file header as a TZ string.
181 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
182 when local time and UT cannot be determined for a timestamp.
184 Changes to build procedure
186 Distribution tarballs now use standard POSIX.1-1988 ustar format
187 instead of GNU format. Although the formats are almost identical
188 for these tarballs, ustar headers' magic fields contain "ustar"
189 instead of "ustar ", and their version fields contain "00" instead
190 of " ". The two formats are planned to diverge more significantly
191 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
192 format becomes obsolete and the tarballs switch to pax format, an
193 extension of ustar. For details about these formats, please see
194 "pax - portable archive interchange", IEEE Std 1003.1-2017,
195 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
198 Release 2021e - 2021-10-21 18:41:00 -0700
200 Changes to future timestamps
202 Palestine will fall back 10-29 (not 10-30) at 01:00.
203 (Thanks to P Chan and Heba Hemad.)
206 Release 2021d - 2021-10-15 13:48:18 -0700
209 Fiji suspends DST for the 2021/2022 season.
210 'zic -r' marks unspecified timestamps with "-00".
212 Changes to future timestamps
214 Fiji will suspend observance of DST for the 2021/2022 season.
215 Assume for now that it will return next year. (Thanks to Jashneel
220 'zic -r' now uses "-00" time zone abbreviations for intervals
221 with UT offsets that are unspecified due to -r truncation.
222 This implements a change in draft Internet RFC 8536bis.
225 Release 2021c - 2021-10-01 14:21:49 -0700
228 Revert most 2021b changes to 'backward'.
229 Fix 'zic -b fat' bug in pre-1970 32-bit data.
230 Fix two Link line typos.
231 Distribute SECURITY file.
233 This release is intended as a bugfix release, to fix compatibility
234 problems and typos reported since 2021b was released.
236 Changes to Link directives
238 Revert almost all of 2021b's changes to the 'backward' file,
239 by moving Link directives back to where they were in 2021a.
240 Although 'zic' doesn't care which source file contains a Link
241 directive, some downstream uses ran into trouble with the move.
242 (Problem reported by Stephen Colebourne for Joda-Time.)
244 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
245 (problem reported by Chris Walton).
247 Fix 'backzone' typo that linked America/Virgin to the wrong
248 location (problem reported by Michael Deckers).
252 Fix a bug in 'zic -b fat' that caused old timestamps to be
253 mishandled in 32-bit-only readers (problem reported by Daniel
256 Changes to documentation
258 Distribute the SECURITY file (problem reported by Andreas Radke).
261 Release 2021b - 2021-09-24 16:23:00 -0700
264 Jordan now starts DST on February's last Thursday.
265 Samoa no longer observes DST.
266 Merge more location-based Zones whose timestamps agree since 1970.
267 Move some backward-compatibility links to 'backward'.
268 Rename Pacific/Enderbury to Pacific/Kanton.
269 Correct many pre-1993 transitions in Malawi, Portugal, etc.
270 zic now creates each output file or link atomically.
271 zic -L no longer omits the POSIX TZ string in its output.
272 zic fixes for truncation and leap second table expiration.
273 zic now follows POSIX for TZ strings using all-year DST.
274 Fix some localtime crashes and bugs in obscure cases.
275 zdump -v now outputs more-useful boundary cases.
276 tzfile.5 better matches a draft successor to RFC 8536.
279 This release is prompted by recent announcements by Jordan and Samoa.
280 It incorporates many other changes that had accumulated since 2021a.
281 However, it omits most proposed changes that merged all Zones
282 agreeing since 1970, as concerns were raised about doing too many of
283 these changes at once. It does keeps some of these changes in the
284 interest of making tzdb more equitable one step at a time; see
285 "Merge more location-based Zones" below.
287 Changes to future timestamps
289 Jordan now starts DST on February's last Thursday.
290 (Thanks to Steffen Thorsen.)
292 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
296 Rename Pacific/Enderbury to Pacific/Kanton. When we added
297 Enderbury in 1993, we did not know that it is uninhabited and that
298 Kanton (population two dozen) is the only inhabited location in
299 that timezone. The old name is now a backward-compatibility link.
301 Changes to past timestamps
303 Correct many pre-1993 transitions, fixing entries originally
304 derived from Shanks, Whitman, and Mundell. The fixes include:
305 - Barbados: standard time was introduced in 1911, not 1932; and
306 DST was observed in 1942-1944
307 - Cook Islands: In 1899 they switched from east to west of GMT,
308 celebrating Christmas for two days. They (and Niue) switched
309 to standard time in 1952, not 1901.
310 - Guyana: corrected LMT for Georgetown; the introduction of
311 standard time in 1911, not 1915; and corrections to 1975 and
313 - Kanton: uninhabited before 1937-08-31
314 - Niue: only observed -11:20 from 1952 through 1964, then went to
315 -11 instead of -11:30
316 - Portugal: DST was observed in 1950
317 - Tonga: corrected LMT; the introduction of standard time in 1945,
318 not 1901; and corrections to the transition from +12:20 to +13
320 Additional fixes to entries in the 'backzone' file include:
321 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
322 - The Gambia: 1933 and 1942 transitions
323 - Malawi: several 1911 through 1925 transitions
324 - Sierra Leone: several 1913 through 1941 transitions, and DST
325 was NOT observed in 1957 through 1962
326 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
329 Merge more location-based Zones whose timestamps agree since 1970,
330 as pre-1970 timestamps are out of scope. This is part of a
331 process that has been ongoing since 2013. This does not affect
332 post-1970 timestamps, and timezone historians who build with 'make
333 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
334 When merging, keep the most-populous location's data, and move
335 data for other locations to 'backzone' with a backward
336 link in 'backward'. For example, move America/Creston data to
337 'backzone' with a link in 'backward' from America/Phoenix because
338 the two timezones' timestamps agree since 1970; this change
339 affects some pre-1968 timestamps in America/Creston because
340 Creston and Phoenix disagreed before 1968. The affected Zones
341 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
342 America/Creston, America/Curacao, America/Nassau,
343 America/Port_of_Spain, Antarctica/DumontDUrville, and
346 Changes to maintenance procedure
348 The new file SECURITY covers how to report security-related bugs.
350 Several backward-compatibility links have been moved to the
351 'backward' file. These links, which range from Africa/Addis_Ababa
352 to Pacific/Saipan, are only for compatibility with now-obsolete
353 guidelines suggesting an entry for every ISO 3166 code.
354 The intercontinental convenience links Asia/Istanbul and
355 Europe/Nicosia have also been moved to 'backward'.
359 zic now creates each output file or link atomically,
360 possibly by creating a temporary file and then renaming it.
361 This avoids races where a TZ setting would temporarily stop
362 working while zic was installing a replacement file or link.
364 zic -L no longer omits the POSIX TZ string in its output.
365 Starting with 2020a, zic -L truncated its output according to the
366 "Expires" directive or "#expires" comment in the leapseconds file.
367 The resulting TZif files omitted daylight saving transitions after
368 the leap second table expired, which led to far less-accurate
369 predictions of times after the expiry. Although future timestamps
370 cannot be converted accurately in the presence of leap seconds, it
371 is more accurate to convert near-future timestamps with a few
372 seconds error than with an hour error, so zic -L no longer
373 truncates output in this way.
375 Instead, when zic -L is given the "Expires" directive, it now
376 outputs the expiration by appending a no-change entry to the leap
377 second table. Although this should work well with most TZif
378 readers, it does not conform to Internet RFC 8536 and some pickier
379 clients (including tzdb 2017c through 2021a) reject it, so
380 "Expires" directives are currently disabled by default. To enable
381 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
382 this new feature it is marked with a new TZif version number 4,
383 a format intended to be documented in a successor to RFC 8536.
385 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
386 that omits leap second information for the range LO..B when LO
387 falls between two leap seconds A and B. Instead, it generates a
388 TZif version 4 file that represents the previously-missing
391 The TZif reader now allows the leap second table to begin with a
392 correction other than -1 or +1, and to contain adjacent
393 transitions with equal corrections. This supports TZif version 4.
395 The TZif reader now lets leap seconds occur less than 28 days
396 apart. This supports possible future TZif extensions.
398 Fix bug that caused 'localtime' etc. to crash when TZ was
399 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
400 not conform to POSIX but does conform to Internet RFC 8536.
402 Fix another bug that caused 'localtime' etc. to crash when TZ was
403 set to a POSIX-conforming but unusual TZ string like
404 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
406 Fix yet another bug that caused 'localtime' etc. to mishandle slim
407 TZif files containing leap seconds after the last explicit
408 transition in the table, or when handling far-future timestamps
409 in slim TZif files lacking leap seconds.
411 Fix localtime misbehavior involving positive leap seconds.
412 This change affects only behavior for "right" system time,
413 which contains leap seconds, and only if the UT offset is
414 not a multiple of 60 seconds when a positive leap second occurs.
415 (No such timezone exists in tzdb, luckily.) Without the fix,
416 the timestamp was ambiguous during a positive leap second.
417 With the fix, any seconds occurring after a positive leap second
418 and within the same localtime minute are counted through 60, not
419 through 59; their UT offset (tm_gmtoff) is the same as before.
420 Here is how the fix affects timestamps in a timezone with UT
421 offset +01:23:45 (5025 seconds) and with a positive leap second at
422 1972-06-30 23:59:60 UTC (78796800):
424 time_t without the fix with the fix
425 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
426 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
428 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
429 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
431 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
432 civil time changes a few seconds before time_t wraps around, when
433 leap seconds are enabled.
435 Fix bug in zic -r; in some cases, the dummy time type after the
436 last time transition disagreed with the TZ string, contrary to
437 Internet RFC 8563 section 3.3.
439 Fix a bug with 'zic -r @X' when X is a negative leap second that
440 has a nonnegative correction. Without the fix, the output file
441 was truncated so that X appeared to be a positive leap second.
442 Fix a similar, even-less-likely bug when truncating at a positive
443 leap second that has a nonpositive correction.
445 zic -r now reports an error if given rolling leap seconds, as this
446 usage has never generally worked and is evidently unused.
448 zic now generates a POSIX-conforming TZ string for TZif files
449 where all-year DST is predicted for the indefinite future.
450 For example, for all-year Eastern Daylight Time, zic now generates
451 "XXX3EDT4,0/0,J365/23" where it previously generated
452 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
453 noting the possibility of POSIX conformance.)
455 zic.c no longer requires sys/wait.h (thanks to spazmodius for
456 noting it wasn't needed).
458 When reading slim TZif files, zdump no longer mishandles leap
459 seconds on the rare platforms where time_t counts leap seconds,
460 fixing a bug introduced in 2014g.
462 zdump -v now outputs timestamps at boundaries of what localtime
463 and gmtime can represent, instead of the less-useful timestamps
464 one day after the minimum and one day before the maximum.
465 (Thanks to Arthur David Olson for prototype code, and to Manuela
466 Friedrich for debugging help.)
468 zdump's -c and -t options are now consistently inclusive for the
469 lower time bound and exclusive for the upper. Formerly they were
470 inconsistent. (Confusion noted by Martin Burnicki.)
472 Changes to build procedure
474 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
475 non-POSIX hosts where malloc doesn't set errno.
476 (Problem reported by Jan Engelhardt.)
478 Changes to documentation
480 tzfile.5 better matches a draft successor to RFC 8536
481 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
484 Release 2021a - 2021-01-24 10:54:57 -0800
486 Changes to future timestamps
488 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
489 (Thanks to Steffen Thorsen.)
492 Release 2020f - 2020-12-29 00:17:46 -0800
494 Change to build procedure
496 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
497 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
500 Release 2020e - 2020-12-22 15:14:34 -0800
503 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
505 Changes to future timestamps
507 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
508 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
510 Changes to past timestamps
512 Correct many pre-1986 transitions, fixing entries originally
513 derived from Shanks. The fixes include:
514 - Australia: several 1917 through 1971 transitions
515 - The Bahamas: several 1941 through 1945 transitions
516 - Bermuda: several 1917 through 1956 transitions
517 - Belize: several 1942 through 1968 transitions
518 - Ghana: several 1915 through 1956 transitions
519 - Israel and Palestine: several 1940 through 1985 transitions
520 - Kenya and adjacent: several 1908 through 1960 transitions
521 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
522 through 1919 transitions
523 - Seychelles: the introduction of standard time in 1907, not 1906
524 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
527 Because of the Australia change, Australia/Currie (King Island) is
528 no longer needed, as it is identical to Australia/Hobart for all
529 timestamps since 1970 and was therefore created by mistake.
530 Australia/Currie has been moved to the 'backward' file and its
531 corrected data moved to the 'backzone' file.
533 Changes to past time zone abbreviations and DST flags
535 To better match legislation in Turks and Caicos, the 2015 shift to
536 year-round observance of -04 is now modeled as AST throughout before
537 returning to Eastern Time with US DST in 2018, rather than as
538 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
540 Changes to documentation
542 The zic man page now documents zic's coalescing of transitions
543 when a zone falls back just before DST springs forward.
546 Release 2020d - 2020-10-21 11:24:13 -0700
549 Palestine ends DST earlier than predicted, on 2020-10-24.
551 Changes to past and future timestamps
553 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
554 as previously predicted (thanks to Sharef Mustafa.) Its
555 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
556 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
557 its spring 2020 transition was on March 28 at 00:00, not March 27
558 (thanks to Pierre Cashon.) This affects Asia/Gaza and
559 Asia/Hebron. Assume future spring and fall transitions will be on
560 the Saturday preceding the last Sunday of March and October,
564 Release 2020c - 2020-10-16 11:15:53 -0700
567 Fiji starts DST later than usual, on 2020-12-20.
569 Changes to future timestamps
571 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
572 previously predicted. DST will still end on 2021-01-17.
573 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
574 the later-than-usual start date is a one-time departure from the
577 Changes to build procedure
579 Rearguard tarballs now contain an empty file pacificnew.
580 Some older downstream software expects this file to exist.
581 (Problem reported by Mike Cullinan.)
584 Release 2020b - 2020-10-06 18:35:04 -0700
587 Revised predictions for Morocco's changes starting in 2023.
588 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
589 Macquarie Island has stayed in sync with Tasmania since 2011.
590 Casey, Antarctica is at +08 in winter and +11 in summer.
591 zic no longer supports -y, nor the TYPE field of Rules.
593 Changes to future timestamps
595 Morocco's spring-forward after Ramadan is now predicted to occur
596 no sooner than two days after Ramadan, instead of one day.
597 (Thanks to Milamber.) The first altered prediction is for 2023,
598 now predicted to spring-forward on April 30 instead of April 23.
600 Changes to past and future timestamps
602 Casey Station, Antarctica has been using +08 in winter and +11 in
603 summer since 2018. The most recent transition from +08 to +11 was
604 2020-10-04 00:01. Also, Macquarie Island has been staying in
605 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
607 Changes to past and future time zone abbreviations and DST flags
609 Canada's Yukon, represented by America/Whitehorse and
610 America/Dawson, changes its time zone rules from -08/-07 to
611 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
612 This change affects only the time zone abbreviation (MST vs PDT)
613 and daylight saving flag for the period between the two dates.
614 (Thanks to Andrew G. Smith.)
616 Changes to past timestamps
618 Correct several transitions for Hungary for 1918/1983.
619 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
620 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
621 time was on 11-01, not 10-01 (thanks to Michael Deckers).
623 The 1891 French transition was on March 16, not March 15. The
624 1911-03-11 French transition was at midnight, not a minute later.
625 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
626 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
630 Support for zic's long-obsolete '-y YEARISTYPE' option has been
631 removed and, with it, so has support for the TYPE field in Rule
632 lines, which is now reserved for compatibility with earlier zic.
633 These features were previously deprecated in release 2015f.
634 (Thanks to Tim Parenti.)
636 zic now defaults to '-b slim' instead of to '-b fat'.
638 zic's new '-l -' and '-p -' options uninstall any existing
639 localtime and posixrules files, respectively.
641 The undocumented and ineffective tzsetwall function has been
644 Changes to build procedure
646 The Makefile now defaults POSIXRULES to '-', so the posixrules
647 feature (obsolete as of 2019b) is no longer installed by default.
649 Changes to documentation and commentary
651 The long-obsolete files pacificnew, systemv, and yearistype.sh have
652 been removed from the distribution. (Thanks to Tim Parenti.)
655 Release 2020a - 2020-04-23 16:03:47 -0700
658 Morocco springs forward on 2020-05-31, not 2020-05-24.
659 Canada's Yukon advanced to -07 year-round on 2020-03-08.
660 America/Nuuk renamed from America/Godthab.
661 zic now supports expiration dates for leap second lists.
663 Changes to future timestamps
665 Morocco's second spring-forward transition in 2020 will be May 31,
666 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
667 Adjust future-year predictions to use the first Sunday after the
668 day after Ramadan, not the first Sunday after Ramadan.
670 Canada's Yukon, represented by America/Whitehorse and
671 America/Dawson, advanced to -07 year-round, beginning with its
672 spring-forward transition on 2020-03-08, and will not fall back on
673 2020-11-01. Although a government press release calls this
674 "permanent Pacific Daylight Saving Time", we prefer MST for
675 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
676 (Thanks to Tim Parenti.)
678 Changes to past timestamps
680 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
682 Changes to timezone identifiers
684 To reflect current usage in English better, America/Godthab has
685 been renamed to America/Nuuk. A backwards-compatibility link
686 remains for the old name.
690 localtime.c no longer mishandles timestamps after the last
691 transition in a TZif file with leap seconds and with daylight
692 saving time transitions projected into the indefinite future.
693 For example, with TZ='America/Los_Angeles' with leap seconds,
694 zdump formerly reported a DST transition on 2038-03-14
695 from 01:59:32.999... to 02:59:33 instead of the correct transition
696 from 01:59:59.999... to 03:00:00.
698 zic -L now supports an Expires line in the leapseconds file, and
699 truncates the TZif output accordingly. This propagates leap
700 second expiration information into the TZif file, and avoids the
701 abovementioned localtime.c bug as well as similar bugs present in
702 many client implementations. If no Expires line is present, zic
703 -L instead truncates the TZif output based on the #expires comment
704 present in leapseconds files distributed by tzdb 2018f and later;
705 however, this usage is obsolescent. For now, the distributed
706 leapseconds file has an Expires line that is commented out, so
707 that the file can be fed to older versions of zic which ignore the
708 commented-out line. Future tzdb distributions are planned to
709 contain a leapseconds file with an Expires line.
711 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
712 set to 1 if the system library supports the feature, and 2 if not.
713 As before, these macros are nonzero if tzcode should support the
714 feature, zero otherwise.
716 The configuration macro ALTZONE now has the same values with the
717 same meaning as HAVE_TZNAME and USG_COMPAT.
719 The code's defense against CRLF in leap-seconds.list is now
720 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
722 Although the undocumented tzsetwall function is not changed in
723 this release, it is now deprecated in preparation for removal in
724 future releases. Due to POSIX requirements, tzsetwall has not
725 worked for some time. Any code that uses it should instead use
726 tzalloc(NULL) or, if portability trumps thread-safety, should
727 unset the TZ environment variable.
729 Changes to commentary
731 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
732 following America/Halifax, and comments about Yukon's "south" and
733 "north" have been corrected to say "east" and "west". (Thanks to
737 Release 2019c - 2019-09-11 08:59:48 -0700
740 Fiji observes DST from 2019-11-10 to 2020-01-12.
741 Norfolk Island starts observing Australian-style DST.
743 Changes to future timestamps
745 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
746 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
747 Adjust future guesses accordingly.
749 Norfolk Island will observe Australian-style DST starting in
750 spring 2019. The first transition is on 2019-10-06. (Thanks to
751 Kyle Czech and Michael Deckers.)
753 Changes to past timestamps
755 Many corrections to time in Turkey from 1940 through 1985.
756 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
758 The Norfolk Island 1975-03-02 transition was at 02:00 standard
759 time, not 02:00 DST. (Thanks to Michael Deckers.)
761 South Korea observed DST from 1948 through 1951. Although this
762 info was supposed to appear in release 2014j, a typo inadvertently
763 suppressed the change. (Thanks to Alois Treindl.)
765 Detroit observed DST in 1967 and 1968 following the US DST rules,
766 except that its 1967 DST began on June 14 at 00:01. (Thanks to
767 Alois Treindl for pointing out that the old data entries were
770 Fix several errors in pre-1970 transitions in Perry County, IN.
771 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
773 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
774 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
775 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
776 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
777 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
778 Königsberg switched to +03 on 04-07 not 01-01.
780 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
781 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
782 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
784 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
785 (Thanks to Michael Deckers.)
787 Changes to past time zone abbreviations and DST flags
789 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
790 is now flagged as DST and is abbreviated HKWT not HKT.
794 leapseconds.awk now relies only on its input data, rather than
795 also relying on its comments. (Inspired by code from Dennis
796 Ferguson and Chris Woodbury.)
798 The code now defends against CRLFs in leap-seconds.list.
799 (Thanks to Brian Inglis and Chris Woodbury.)
801 Changes to documentation and commentary
803 theory.html discusses leap seconds. (Thanks to Steve Summit.)
805 Nashville's newspapers dueled about the time of day in the 1950s.
806 (Thanks to John Seigenthaler.)
808 Liechtenstein observed Swiss DST in 1941/2.
809 (Thanks to Alois Treindl.)
812 Release 2019b - 2019-07-01 00:09:53 -0700
815 Brazil no longer observes DST.
816 'zic -b slim' outputs smaller TZif files; please try it out.
817 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
819 Changes to future timestamps
821 Brazil has canceled DST and will stay on standard time indefinitely.
822 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
825 Predictions for Morocco now go through 2087 instead of 2037, to
826 work around a problem on newlib when using TZif files output by
827 zic 2019a or earlier. (Problem reported by David Gauchard.)
829 Changes to past and future timestamps
831 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
832 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
833 future transitions to be March's last Friday at 00:00.
835 Changes to past timestamps
837 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
838 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
839 not 09-15 at 00:00. In 1946 its spring-forward transition was on
840 04-21 at 00:00, not the previous day at 03:30. From 1946 through
841 1952 its fall-back transitions occurred at 04:30, not at 03:30.
842 In 1947 its fall-back transition was on 11-30, not 12-30.
845 Changes to past time zone abbreviations
847 Italy's 1866 transition to Rome Mean Time was on December 12, not
848 September 22. This affects only the time zone abbreviation for
849 Europe/Rome between those dates. (Thanks to Stephen Trainor and
852 Changes affecting metadata only
854 Add info about the Crimea situation in zone1970.tab and zone.tab.
855 (Problem reported by Serhii Demediuk.)
859 zic's new -b option supports a way to control data bloat and to
860 test for year-2038 bugs in software that reads TZif files.
861 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
862 for example, changing from fat to slim shrinks the Europe/London
863 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
864 files represent the same set of timestamps and use the same TZif
865 format as documented in tzfile(5) and in Internet RFC 8536.
866 Fat format attempts to work around bugs or incompatibilities in
867 older software, notably software that mishandles 64-bit TZif data
868 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
869 Slim format is more efficient and does not work around 64-bit bugs
870 or obsolete TZ strings. Currently zic defaults to fat format
871 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
872 out-of-the-box default is intended to change in future releases
873 as the buggy software often mishandles timestamps anyway.
875 zic no longer treats a set of rules ending in 2037 specially.
876 Previously, zic assumed that such a ruleset meant that future
877 timestamps could not be predicted, and therefore omitted a
878 POSIX-like TZ string in the TZif output. The old behavior is no
879 longer needed for current tzdata, and caused problems with newlib
880 when used with older tzdata (reported by David Gauchard).
882 zic no longer generates some artifact transitions. For example,
883 Europe/London no longer has a no-op transition in January 1996.
885 Changes to build procedure
887 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
890 Changes to documentation and commentary
892 The Makefile now documents the POSIXRULES macro as being obsolete,
893 and similarly, zic's -p POSIXRULES option is now documented as
894 being obsolete. Although the POSIXRULES feature still exists and
895 works as before, in practice it is rarely used for its intended
896 purpose, and it does not work either in the default reference
897 implementation (for timestamps after 2037) or in common
898 implementations such as GNU/Linux (for contemporary timestamps).
899 Since POSIXRULES was designed primarily as a temporary transition
900 facility for System V platforms that died off decades ago, it is
901 being decommissioned rather than institutionalized.
903 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
906 Release 2019a - 2019-03-25 22:01:33 -0700
909 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
910 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
912 Changes to past and future timestamps
914 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
915 previously predicted. Adjust our prediction by guessing that spring
916 transitions will be between 24 and 30 March, which matches recent practice
917 since 2016. (Thanks to Even Scharning and Tim Parenti.)
919 Metlakatla ended its observance of Pacific standard time,
920 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
921 Stanley and Tim Parenti.)
923 Changes to past timestamps
925 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
926 (Thanks to Alois Treindl and Isaac Starkman.)
928 Changes to time zone abbreviations
930 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
931 of being a separate zone that generates the abbreviation "UCT",
932 which nowadays is typically a typo. (Problem reported by Isiah
937 zic now has an -r option to limit the time range of output data.
938 For example, 'zic -r @1000000000' limits the output data to
939 timestamps starting 1000000000 seconds after the Epoch.
940 This helps shrink output size and can be useful for applications
941 not needing the full timestamp history, such as TZDIST truncation;
942 see Internet RFC 8536 section 5.1. (Inspired by a feature request
943 from Christopher Wong, helped along by bug reports from Wong and
946 Changes to documentation
948 Mention Internet RFC 8536 (February 2019), which documents TZif.
950 tz-link.html now cites tzdata-meta
951 <https://tzdata-meta.timtimeonline.com/>.
954 Release 2018i - 2018-12-30 11:05:43 -0800
957 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
959 Changes to future timestamps
961 Due to a change in government, São Tomé and Príncipe switches back
962 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
963 Nasardinov and Michael Deckers.)
966 Release 2018h - 2018-12-23 17:59:32 -0800
969 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
970 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
971 Metlakatla, Alaska observes PST this winter only.
972 Guess Morocco will continue to adjust clocks around Ramadan.
973 Add predictions for Iran from 2038 through 2090.
975 Changes to future timestamps
977 Guess that Morocco will continue to fall back just before and
978 spring forward just after Ramadan, the practice since 2012.
979 (Thanks to Maamar Abdelkader.) This means Morocco will observe
980 negative DST during Ramadan in main and vanguard formats, and in
981 rearguard format it stays in the +00 timezone and observes
982 ordinary DST in all months other than Ramadan. As before, extend
983 this guesswork to the year 2037. As a consequence, Morocco is
984 scheduled to observe three DST transitions in some Gregorian years
985 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
988 The table of exact transitions for Iranian DST has been extended.
989 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
990 It now cuts off before 2091 as there is doubt about how the Persian
991 calendar will treat 2091. This change predicts DST transitions in
992 2038-9, 2042-3, and 2046-7 to occur one day later than previously
993 predicted. As before, post-cutoff transitions are approximated.
995 Changes to past and future timestamps
997 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
998 +05 on 2018-12-21. This is a zone split as Qostanay (aka
999 Kostanay) did not switch, so create a zone Asia/Qostanay.
1001 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
1002 It did not change clocks that day and remains on -08 this winter.
1003 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
1004 rules next spring, so this change affects only timestamps
1005 from 2018-11-04 through 2019-03-10.
1007 Change to past timestamps
1009 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
1010 not 00:00. I transcribed the time incorrectly from Shanks.
1011 (Thanks to Phake Nick.)
1013 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
1014 (Thanks to Phake Nick.)
1016 Guam observed DST irregularly from 1959 through 1977.
1017 (Thanks to Phake Nick.)
1019 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
1020 10-01 changed standard time to +08:30 (not +08). Its transition
1021 back to +08 after WWII was on 1945-09-15, not the previous day.
1022 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
1023 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1024 its 1952 fallback was on 11-02 (not 10-25).
1026 This release contains many changes to timestamps before 1946 due
1027 to Japanese possession or occupation of Pacific/Chuuk,
1028 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1029 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1030 (Thanks to Phake Nick.)
1032 Assume that the Spanish East Indies was like the Philippines and
1033 observed American time until the end of 1844. This affects
1034 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1036 Changes to past tm_isdst flags
1038 For the recent Morocco change, the tm_isdst flag should be 1 from
1039 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1040 Give a URL to the official decree. (Thanks to Matt Johnson.)
1043 Release 2018g - 2018-10-26 22:22:45 -0700
1046 Morocco switches to permanent +01 on 2018-10-28.
1048 Changes to future timestamps
1050 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1051 so its clocks will not fall back as previously scheduled.
1052 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1056 When generating TZif files with leap seconds, zic no longer uses a
1057 format that trips up older 32-bit clients, fixing a bug introduced
1058 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1059 for QTBUG-53071 now also works for TZif files with leap seconds.
1061 The translator to rearguard format now rewrites the line
1062 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1063 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1064 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1065 and earlier. (Reported by Christos Zoulas.)
1067 Changes to past time zone abbreviations
1069 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1070 This reverts to 2011h, as the abbreviation change in 2011i was
1073 Changes to documentation
1075 tzfile.5 has new sections on interoperability issues.
1078 Release 2018f - 2018-10-18 00:14:18 -0700
1081 Volgograd moves from +03 to +04 on 2018-10-28.
1082 Fiji ends DST 2019-01-13, not 2019-01-20.
1083 Most of Chile changes DST dates, effective 2019-04-06.
1085 Changes to future timestamps
1087 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1088 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1090 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1091 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1094 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1095 time, and resume DST on the first Saturday in September at 24:00 mainland
1096 time. The changes are effective from 2019-04-06, and do not affect the
1097 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1098 and Tim Parenti.) Adjust future predictions accordingly.
1100 Changes to past timestamps
1102 The 2018-05-05 North Korea 30-minute time zone change took place
1103 at 23:30 the previous day, not at 00:00 that day.
1105 China's 1988 spring-forward transition was on April 17, not
1106 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1109 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1110 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1111 temporarily switched to +09/+10 during World War II. Macau
1112 observed DST in 1942/79, not 1961/80, and there were several
1113 errors for transition times and dates. (Thanks to P Chan.)
1115 The 1948-1951 fallback transitions in Japan were at 25:00 on
1116 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1117 zic turns this into 01:00 on the day after September's second
1118 Saturday, which is the best that POSIX or C platforms can do.
1120 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1121 paper by Li Yu, replacing more-questionable data from Shanks.
1123 Changes to time zone abbreviations
1125 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1129 zic now always generates TZif files where time type 0 is used for
1130 timestamps before the first transition. This simplifies the
1131 reading of TZif files and should not affect behavior of existing
1132 TZif readers because the same set of time types is used; only
1133 their internal indexes may have changed. This affects only the
1134 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1135 EET, which previously used nonzero types for these timestamps.
1137 Because of the type 0 change, zic no longer outputs a dummy
1138 transition at time -2**59 (before the Big Bang), as clients should
1139 no longer need this to handle historical timestamps correctly.
1140 This reverts a change introduced in 2013d and shrinks most TZif
1141 files by a few bytes.
1143 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1144 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1145 occurs at 18:00 on the Saturday before the last Sunday in April.
1146 This behavior was documented in 2018a but the code did not
1147 entirely match the documentation.
1149 localtime.c no longer requires at least one time type in TZif
1150 files that lack transitions or have a POSIX-style TZ string. This
1151 future-proofs the code against possible future extensions to the
1152 format that would allow TZif files with POSIX-style TZ strings and
1153 without transitions or time types.
1155 A read-access subscript error in localtime.c has been fixed.
1156 It could occur only in TZif files with timecnt == 0, something that
1157 does not happen in practice now but could happen in future versions.
1159 localtime.c no longer ignores TZif POSIX-style TZ strings that
1160 specify only standard time. Instead, these TZ strings now
1161 override the default time type for timestamps after the last
1162 transition (or for all timestamps if there are no transitions),
1163 just as DST strings specifying DST have always done.
1165 leapseconds.awk now outputs "#updated" and "#expires" comments,
1166 and supports leap seconds at the ends of months other than June
1167 and December. (Inspired by suggestions from Chris Woodbury.)
1169 Changes to documentation
1171 New restrictions: A Rule name must start with a character that
1172 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1173 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1174 The latter restriction makes room for future extensions (a
1175 possibility noted by Tom Lane).
1177 tzfile.5 now documents what time types apply before the first and
1178 after the last transition, if any.
1180 Documentation now uses the spelling "timezone" for a TZ setting
1181 that determines timestamp history, and "time zone" for a
1182 geographic region currently sharing the same standard time.
1184 The name "TZif" is now used for the tz binary data format.
1186 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1187 (Thanks to Aldrin Martoq for the link.)
1189 Changes to build procedure
1191 New 'make' target 'rearguard_tarballs' to build the rearguard
1192 tarball only. This is a convenience on platforms that lack lzip
1193 if you want to build the rearguard tarball. (Problem reported by
1196 tzdata.zi is now more stable from release to release. (Problem
1197 noted by Tom Lane.) It is also a bit shorter.
1199 tzdata.zi now can contain comment lines documenting configuration
1200 information, such as which data format was selected, which input
1201 files were used, and how leap seconds are treated. (Problems
1202 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1203 are used these comment lines are absent, for backward
1204 compatibility. A redistributor intending to alter its copy of the
1205 files should also append "-LABEL" to the 'version' file's first
1206 line, where "LABEL" identifies the redistributor's change.
1209 Release 2018e - 2018-05-01 23:42:51 -0700
1213 North Korea switches back to +09 on 2018-05-05.
1214 The main format uses negative DST again, for Ireland etc.
1215 'make tarballs' now also builds a rearguard tarball.
1216 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1218 Changes to past and future timestamps
1220 North Korea switches back from +0830 to +09 on 2018-05-05.
1221 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1224 Bring back the negative-DST changes of 2018a, except be more
1225 compatible with data parsers that do not support negative DST.
1226 Also, this now affects historical timestamps in Namibia and the
1227 former Czechoslovakia, not just Ireland. The main format now uses
1228 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1229 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1230 does not affect UT offsets, only time zone abbreviations and the
1231 tm_isdst flag. Also, this does not affect rearguard or vanguard
1232 formats; effectively the main format now uses vanguard instead of
1233 rearguard format. Data parsers that do not support negative DST
1234 can still use data from the rearguard tarball described below.
1236 Changes to build procedure
1238 The command 'make tarballs' now also builds the tarball
1239 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1240 except that it uses rearguard format intended for trailing-edge
1243 Changes to data format and to code
1245 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1246 suffix, which specifies whether the adjusted time is standard time
1247 or daylight saving time. If no suffix is given, daylight saving
1248 time is used if and only if the SAVE column is nonzero; this is
1249 the longstanding behavior. Although this new feature is not used
1250 in tzdata, it could be used to specify the legal time in Namibia
1251 1994-2017, as opposed to the popular time (see below).
1253 Changes to past timestamps
1255 From 1994 through 2017 Namibia observed DST in winter, not summer.
1256 That is, it used negative DST, as Ireland still does. This change
1257 does not affect UTC offsets; it affects only the tm_isdst flag and
1258 the abbreviation used during summer, which is now CAT, not WAST.
1259 Although (as noted by Michael Deckers) summer and winter time were
1260 both simply called "standard time" in Namibian law, in common
1261 practice winter time was considered to be DST (as noted by Stephen
1262 Colebourne). The full effect of this change is only in vanguard
1263 and main format; in rearguard format, the tm_isdst flag is still
1264 zero in winter and nonzero in summer.
1266 In 1946/7 Czechoslovakia also observed negative DST in winter.
1267 The full effect of this change is only in vanguard and main
1268 formats; in rearguard format, it is modeled as plain GMT without
1269 daylight saving. Also, the dates of some 1944/5 DST transitions
1270 in Czechoslovakia have been changed.
1273 Release 2018d - 2018-03-22 07:05:46 -0700
1277 Palestine starts DST a week earlier in 2018.
1278 Add support for vanguard and rearguard data consumers.
1279 Add subsecond precision to source data format, though not to data.
1281 Changes to future timestamps
1283 In 2018, Palestine starts DST on March 24, not March 31.
1284 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1286 Changes to past and future timestamps
1288 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1289 at 04:00. (Thanks to Steffen Thorsen.)
1291 Changes to past timestamps
1293 Historical transitions for Uruguay, represented by
1294 America/Montevideo, have been updated per official legal documents,
1295 replacing previous data mainly originating from the inventions of
1296 Shanks & Pottenger. This has resulted in adjustments ranging from
1297 30 to 90 minutes in either direction over at least two dozen
1298 distinct periods ranging from one day to several years in length.
1299 A mere handful of pre-1991 transitions are unaffected; data since
1300 then has come from more reliable contemporaneous reporting. These
1301 changes affect various timestamps in 1920-1923, 1936, 1939,
1302 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1303 Additionally, Uruguay's pre-standard-time UT offset has been
1304 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1305 match the location of the Observatory of the National Meteorological
1306 Institute in Montevideo.
1307 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1309 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1310 (Thanks to Kerry Shetline.)
1312 Fix the 1912-01-01 transition for Portugal and its colonies.
1313 This transition was at 00:00 according to the new UT offset, not
1314 according to the old one. Also assume that Cape Verde switched on
1315 the same date as the rest, not in 1907. This affects
1316 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1317 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1318 (Thanks to Michael Deckers.)
1320 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1323 Changes to past time zone abbreviations
1325 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1326 is no clock change associated with the transition.
1328 Changes to build procedure
1330 The new DATAFORM macro in the Makefile lets the installer choose
1331 among three source data formats. The idea is to lessen downstream
1332 disruption when data formats are improved.
1334 * DATAFORM=vanguard installs from the latest, bleeding-edge
1335 format. DATAFORM=main (the default) installs from the format
1336 used in the 'africa' etc. files. DATAFORM=rearguard installs
1337 from a trailing-edge format. Eventually, elements of today's
1338 vanguard format should move to the main format, and similarly
1339 the main format's features should eventually move to the
1342 * In the current version, the main and rearguard formats are
1343 identical and match that of 2018c, so this change does not
1344 affect default behavior. The vanguard format currently contains
1345 one feature not in the main format: negative SAVE values. This
1346 improves support for Ireland, which uses Irish Standard Time
1347 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1348 supported negative SAVE values for decades, and this feature
1349 should move to the main format soon. However, it will not move
1350 to the rearguard format for quite some time because some
1351 downstream parsers do not support it.
1353 * The build procedure constructs three files vanguard.zi, main.zi,
1354 and rearguard.zi, one for each format. Although the files
1355 represent essentially the same data, they may have minor
1356 discrepancies that users are not likely to notice. The files
1357 are intended for downstream data consumers and are not
1358 installed. Zoneinfo parsers that do not support negative SAVE values
1359 should start using rearguard.zi, so that they will be unaffected
1360 when the negative-DST feature moves from vanguard to main.
1361 Bleeding-edge Zoneinfo parsers that support the new features
1362 already can use vanguard.zi; in this respect, current tzcode is
1365 The Makefile should now be safe for parallelized builds, and 'make
1366 -j to2050new.tzs' is now much faster on a multiprocessor host
1369 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1370 prepends TZDIR/ to file names that do not begin with '/'. This is
1371 not recommended for general use, due to its security implications.
1372 (From a suggestion by Manuela Friedrich.)
1376 zic now accepts subsecond precision in expressions like
1377 00:19:32.13, which is approximately the legal time of the
1378 Netherlands from 1835 to 1937. However, because it is
1379 questionable whether the few recorded uses of non-integer offsets
1380 had subsecond precision in practice, there are no plans for tzdata
1381 to use this feature. (Thanks to Steve Allen for pointing out
1382 the limitations of historical data in this area.)
1384 The code is a bit more portable to MS-Windows. Installers can
1385 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1386 reserve identifiers like 'localtime'. (Thanks to Manuela
1389 Changes to documentation and commentary
1391 theory.html now outlines tzdb's extensions to POSIX's model for
1392 civil time, and has a section "POSIX features no longer needed"
1393 that lists POSIX API components that are now vestigial.
1394 (From suggestions by Steve Summit.) It also better distinguishes
1395 time zones from tz regions. (From a suggestion by Guy Harris.)
1397 Commentary is now more consistent about using the phrase "daylight
1398 saving time", to match the C name tm_isdst. Daylight saving time
1399 need not occur in summer, and need not have a positive offset from
1402 Commentary about historical transitions in Uruguay has been expanded
1403 with links to many relevant legal documents.
1404 (Thanks to Tim Parenti.)
1406 Commentary now uses some non-ASCII characters with Unicode value
1407 less than U+0100, as they can be useful and should work even with
1408 older editors such as XEmacs.
1411 Release 2018c - 2018-01-22 23:00:44 -0800
1414 Revert Irish changes that relied on negative SAVE values.
1418 Revert the 2018a change to Europe/Dublin. As before, this change
1419 does not affect UT offsets or abbreviations; it affects only
1420 whether timestamps are considered to be standard time or
1421 daylight-saving time, as expressed in the tm_isdst flag of C's
1422 struct tm type. This reversion is intended to be a temporary
1423 workaround for problems discovered with downstream uses of
1424 releases 2018a and 2018b, which implemented Irish time by using
1425 negative SAVE values in the Eire rules of the 'europe' file.
1426 Although negative SAVE values have been part of tzcode for many
1427 years and are supported by many platforms, they were not
1428 documented before 2018a and ICU and OpenJDK do not currently
1429 support them. A mechanism to export data to platforms lacking
1430 support for negative DST is planned to be developed before the
1431 change is reapplied. (Problems reported by Deborah Goldsmith and
1432 Stephen Colebourne.)
1434 Changes to past timestamps
1436 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1437 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1439 Changes to build procedure
1441 The build procedure now works around mawk 1.3.3's lack of support
1442 for character class expressions. (Problem reported by Ohyama.)
1445 Release 2018b - 2018-01-17 23:24:48 -0800
1448 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1450 Changes to build procedure
1452 The distribution now contains the file 'pacificnew' again.
1453 This file was inadvertently omitted in the 2018a distribution.
1454 (Problem reported by Matias Fonzo.)
1457 Release 2018a - 2018-01-12 22:29:21 -0800
1460 São Tomé and Príncipe switched from +00 to +01.
1461 Brazil's DST will now start on November's first Sunday.
1462 Ireland's standard time is now in the summer, not the winter.
1463 Use Debian-style installation locations, instead of 4.3BSD-style.
1466 Changes to past and future timestamps
1468 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1469 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1471 Changes to future timestamps
1473 Starting in 2018 southern Brazil will begin DST on November's
1474 first Sunday instead of October's third Sunday. (Thanks to
1477 Changes to past timestamps
1479 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1480 been corrected. The 'backzone' and 'zone.tab' files did not agree
1481 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1484 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1485 BST instead of BOST, to be more consistent with the convention
1486 used for Latvian Summer Time (1918-9) and for British Summer Time.
1490 Change Europe/Dublin so that it observes Irish Standard Time (UT
1491 +01) in summer and GMT (as negative daylight-saving) in winter,
1492 instead of observing standard time (GMT) in winter and Irish
1493 Summer Time (UT +01) in summer. This change does not affect UT
1494 offsets or abbreviations; it affects only whether timestamps are
1495 considered to be standard time or daylight-saving time, as
1496 expressed in the tm_isdst flag of C's struct tm type.
1497 (Discrepancy noted by Derick Rethans.)
1499 Changes to build procedure
1501 The default installation locations have been changed to mostly
1502 match Debian circa 2017, instead of being designed as an add-on to
1503 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1504 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1505 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1506 locations more precisely. (This responds to suggestions from
1507 Brian Inglis and from Steve Summit.)
1509 The default installation procedure no longer creates the
1510 backward-compatibility link US/Pacific-New, which causes
1511 confusion during user setup (e.g., see Debian bug 815200).
1512 Use 'make BACKWARD="backward pacificnew"' to create the link
1513 anyway, for now. Eventually we plan to remove the link entirely.
1515 tzdata.zi now contains a version-number comment.
1516 (Suggested by Tom Lane.)
1518 The Makefile now quotes values like BACKWARD more carefully when
1519 passing them to the shell. (Problem reported by Zefram.)
1521 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1522 that have snprintf and use pre-C99 compilers. (Problem reported
1527 zic has a new option -t FILE that specifies the location of the
1528 file that determines local time when TZ is unset. The default for
1529 this location can be configured via the new TZDEFAULT makefile
1530 macro, which defaults to /etc/localtime.
1532 Diagnostics and commentary now distinguish UT from UTC more
1533 carefully; see theory.html for more information about UT vs UTC.
1535 zic has been ported to GCC 8's -Wstringop-truncation option.
1536 (Problem reported by Martin Sebor.)
1538 Changes to documentation and commentary
1540 The zic man page now documents the longstanding behavior that
1541 times and years can be out of the usual range, with negative times
1542 counting backwards from midnight and with year 0 preceding year 1.
1543 (Problem reported by Michael Deckers.)
1545 The theory.html file now mentions the POSIX limit of six chars
1546 per abbreviation, and lists alphabetic abbreviations used.
1548 The files tz-art.htm and tz-link.htm have been renamed to
1549 tz-art.html and tz-link.html, respectively, for consistency with
1550 other file names and to simplify web server configuration.
1553 Release 2017c - 2017-10-20 14:49:34 -0700
1556 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1557 Fiji ends DST 2018-01-14, not 2018-01-21.
1558 Namibia switches from +01/+02 to +02 on 2018-04-01.
1559 Sudan switches from +03 to +02 on 2017-11-01.
1560 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1561 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1562 A new file tzdata.zi now holds a small text copy of all data.
1563 The zic input format has been regularized slightly.
1565 Changes to future timestamps
1567 Northern Cyprus has decided to resume EU rules starting
1568 2017-10-29, thus reinstituting winter time.
1570 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1571 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1574 Namibia will switch from +01 with DST to +02 all year on
1575 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1576 at 02:00. (Thanks to Steffen Thorsen.)
1578 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1579 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1580 Africa/Juba is no longer a link to Africa/Khartoum.
1582 Tonga has likely ended its experiment with DST, and will not
1583 adjust its clocks on 2017-11-05. Although Tonga has not announced
1584 whether it will continue to observe DST, the IATA is assuming that
1585 it will not. (Thanks to David Wade.)
1587 Turks & Caicos will switch from -04 all year to -05 with US DST on
1588 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1589 at 02:00. (Thanks to Steffen Thorsen.)
1591 Changes to past timestamps
1593 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1594 (Thanks to Arthur David Olson.)
1596 Detroit did not observe DST in 1967.
1598 Use railway time for Asia/Kolkata before 1941, by switching to
1599 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1600 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1602 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1603 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1605 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1606 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1608 Adjust the 1867 transition in Alaska to better reflect the
1609 historical record, by changing it to occur on 1867-10-18 at 15:30
1610 Sitka time rather than at the start of 1867-10-17 local time.
1611 Although strictly speaking this is accurate only for Sitka,
1612 the rest of Alaska's blanks need to be filled in somehow.
1614 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1615 (Thanks to Michael Deckers.)
1617 Add 7 s to the UT offset in Asia/Yangon before 1920.
1619 Changes to zone names
1621 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1622 exceeded the 14-character limit and was an unused misnomer anyway.
1624 Changes to build procedure
1626 To support applications that prefer to read time zone data in text
1627 form, two zic input files tzdata.zi and leapseconds are now
1628 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1629 leapseconds tzdata.zi' can reproduce the tzdata binary files
1630 without and with leap seconds, respectively. To prevent these two
1631 new files from being installed, use 'make TZDATA_TEXT=', and to
1632 suppress leap seconds from the tzdata text installation, use 'make
1633 TZDATA_TEXT=tzdata.zi'.
1635 'make BACKWARD=' now suppresses backward-compatibility names
1636 like 'US/Pacific' that are defined in the 'backward' and
1639 'make check' now works on systems that lack a UTF-8 locale,
1640 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1641 the name of a UTF-8 locale, if you have one.
1643 Y2K runtime checks are no longer enabled by default. Add
1644 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1645 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1646 to disable them. (New name suggested by Brian Inglis.)
1648 The build procedure for zdump now works on AIX 7.1.
1649 (Problem reported by Kees Dekker.)
1653 zic and the reference runtime now reject multiple leap seconds
1654 within 28 days of each other, or leap seconds before the Epoch.
1655 As a result, support for double leap seconds, which was
1656 obsolescent and undocumented, has been removed. Double leap
1657 seconds were an error in the C89 standard; they have never existed
1658 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1659 noticing glitches in the code that uncovered this problem.)
1661 zic now warns about use of the obsolescent and undocumented -y
1662 option, and about use of the obsolescent TYPE field of Rule lines.
1664 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1665 weekdays; formerly it rejected them due to a bug. Conversely, zic
1666 no longer considers non-prefixes to be abbreviations; for example,
1667 it no longer accepts "lF" as an abbreviation for "lastFriday".
1668 Also, zic warns about the undocumented usage with a "last-"
1669 prefix, e.g., "last-Fri".
1671 Similarly, zic now accepts the unambiguous abbreviation "L" for
1672 "Link" in ordinary context and for "Leap" in leap-second context.
1673 Conversely, zic no longer accepts non-prefixes such as "La" as
1674 abbreviations for words like "Leap".
1676 zic no longer accepts leap second lines in ordinary input, or
1677 ordinary lines in leap second input. Formerly, zic sometimes
1678 warned about this undocumented usage and handled it incorrectly.
1680 The new macro HAVE_TZNAME governs whether the tzname external
1681 variable is exported, instead of USG_COMPAT. USG_COMPAT now
1682 governs only the external variables "timezone" and "daylight".
1683 This change is needed because the three variables are not in the
1684 same category: although POSIX requires tzname, it specifies the
1685 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
1686 if not defined, the code attempts to guess it from other macros.
1688 localtime.c and difftime.c no longer require stdio.h, and .c files
1689 other than zic.c no longer require sys/wait.h.
1691 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
1693 Calculation of time_t extrema works around a bug in GCC 4.8.4
1694 (Reported by Stan Shebs and Joseph Myers.)
1696 zic.c no longer mistranslates formats of line numbers in non-English
1697 locales. (Problem reported by Benno Schulenberg.)
1699 Several minor changes have been made to the code to make it a
1700 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
1701 Dekker for reporting the problems.)
1703 Changes to documentation and commentary
1705 The two new files 'theory.html' and 'calendars' contain the
1706 contents of the removed file 'Theory'. The goal is to document
1707 tzdb theory more accessibly.
1709 The zic man page now documents abbreviation rules.
1711 tz-link.htm now covers how to apply tzdata changes to clients.
1712 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
1714 The leap-seconds.list URL has been updated to something that is
1715 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
1717 Release 2017b - 2017-03-17 07:30:38 -0700
1719 Briefly: Haiti has resumed DST.
1721 Changes to past and future timestamps
1723 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
1725 Changes to past timestamps
1727 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1729 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1730 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
1734 The reference localtime implementation now falls back on the
1735 current US daylight-saving transition rules rather than the
1736 1987-2006 rules. This fallback occurs only when (1) the TZ
1737 environment variable has a value like "AST4ADT" that asks
1738 for daylight saving time but does not specify the rules, (2) there
1739 is no file by that name, and (3) the TZDEFRULES file cannot be
1740 loaded. (Thanks to Tom Lane.)
1743 Release 2017a - 2017-02-28 00:05:36 -0800
1745 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1748 Changes to future timestamps
1750 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
1752 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1753 Its clocks diverge from America/Santiago starting 2017-05-13 at
1754 23:00, hiving off a new zone America/Punta_Arenas. Although the
1755 Chilean government says this change expires in May 2019, for now
1756 assume it's permanent. (Thanks to Juan Correa and Deborah
1757 Goldsmith.) This also affects Antarctica/Palmer.
1759 Changes to past timestamps
1761 Fix many entries for historical timestamps for Europe/Madrid
1762 before 1979, to agree with tables compiled by Pere Planesas of the
1763 National Astronomical Observatory of Spain. As a side effect,
1764 this changes some timestamps for Africa/Ceuta before 1929, which
1765 are probably guesswork anyway. (Thanks to Steve Allen and
1766 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1767 correcting the 1901 transition.)
1769 Ecuador observed DST from 1992-11-28 to 1993-02-05.
1770 (Thanks to Alois Treindl.)
1772 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1773 (Thanks to Stepan Golosunov.)
1775 Changes to past and future time zone abbreviations
1777 Switch to numeric time zone abbreviations for South America, as
1778 part of the ongoing project of removing invented abbreviations.
1779 This avoids the need to invent an abbreviation for the new Chilean
1780 new zone. Similarly, switch from invented to numeric time zone
1781 abbreviations for Afghanistan, American Samoa, the Azores,
1782 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1783 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1784 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1785 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1786 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1787 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1788 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1789 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1790 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1791 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1792 for half-hour daylight saving time in Belize before 1944 and in
1793 the Dominican Republic before 1975; and for Canary Islands before
1794 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1795 Indian Summer Time before 1942, for Indonesia before around 1964,
1796 for Kenya before 1960, for Liberia before 1973, for Madeira before
1797 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1798 Pakistan before 1971, for Western Sahara before 1977, and for
1799 Zaporozhye in 1880-1924.
1801 For Alaska time from 1900 through 1967, instead of "CAT" use the
1802 abbreviation "AST", the abbreviation commonly used at the time
1803 (Atlantic Standard Time had not been standardized yet). Use "AWT"
1804 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1806 Use "CST" and "CDT" instead of invented abbreviations for Macau
1807 before 1999 and Taiwan before 1938, and use "JST" instead of the
1808 invented abbreviation "JCST" for Japan and Korea before 1938.
1810 Change to database entry category
1812 Move the Pacific/Johnston link from 'australasia' to 'backward',
1813 since Johnston is now uninhabited.
1817 zic no longer mishandles some transitions in January 2038 when it
1818 attempts to work around Qt bug 53071. This fixes a bug affecting
1819 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
1820 now contains a workaround, useful when loading a file generated by
1821 a buggy zic. (Problem and localtime.c fix reported by Bradley
1824 zdump -i now outputs non-hour numeric time zone abbreviations
1825 without a colon, e.g., "+0530" rather than "+05:30". This agrees
1826 with zic %z and with common practice, and simplifies auditing of
1829 zdump is now buildable again with -DUSE_LTZ=0.
1830 (Problem reported by Joseph Myers.)
1832 zdump.c now always includes private.h, to avoid code duplication
1833 with private.h. (Problem reported by Kees Dekker.)
1835 localtime.c no longer mishandles early or late timestamps
1836 when TZ is set to a POSIX-style string that specifies DST.
1837 (Problem reported by Kees Dekker.)
1839 date and strftime now cause %z to generate "-0000" instead of
1840 "+0000" when the UT offset is zero and the time zone abbreviation
1843 Changes to documentation and commentary
1845 The 'Theory' file now better documents choice of historical time
1846 zone abbreviations. (Problems reported by Michael Deckers.)
1848 tz-link.htm now covers leap smearing, which is popular in clouds.
1851 Release 2016j - 2016-11-22 23:17:13 -0800
1853 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1855 Changes to future timestamps
1857 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
1858 This hives off a new zone Europe/Saratov from Europe/Volgograd.
1859 (Thanks to Yuri Konotopov and Stepan Golosunov.)
1861 Changes to past timestamps
1863 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
1864 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
1865 1999, not fall 1994. (Thanks to Stepan Golosunov.)
1867 Changes to past time zone abbreviations
1869 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
1870 summer time before 1948. The old use of "EET" was a typo.
1874 zic no longer mishandles file systems that lack hard links, fixing
1875 bugs introduced in 2016g. (Problems reported by Tom Lane.)
1876 Also, when the destination already contains symbolic links, zic
1877 should now work better on systems where the 'link' system call
1878 does not follow symbolic links.
1880 Changes to documentation and commentary
1882 tz-link.htm now documents the relationship between release version
1883 numbers and development-repository commit tags. (Suggested by
1886 The 'Theory' file now documents UT.
1888 iso3166.tab now accents "Curaçao", and commentary now mentions
1889 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
1892 Release 2016i - 2016-11-01 23:19:52 -0700
1894 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
1895 reintroduces DST on 2016-11-06.
1897 Changes to future timestamps
1899 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
1900 2017-01-15 at 03:00. Assume future observances in Tonga will be
1901 from the first Sunday in November through the third Sunday in
1902 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
1903 time zone abbreviations for this zone.
1905 Changes to past and future timestamps
1907 Northern Cyprus is now +03 year round, causing a split in Cyprus
1908 time zones starting 2016-10-30 at 04:00. This creates a zone
1909 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
1911 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
1912 (Thanks to Steffen Thorsen.)
1914 Changes to past timestamps
1916 Several corrections were made for pre-1975 timestamps in Italy.
1917 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
1920 First, the 1893-11-01 00:00 transition in Italy used the new UT
1921 offset (+01), not the old (+00:49:56). (Thanks to Michael
1924 Second, rules for daylight saving in Italy were changed to agree
1925 with Italy's National Institute of Metrological Research (INRiM)
1926 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
1927 Inglis, and Michael Deckers):
1929 The 1916-06-03 transition was at 24:00, not 00:00.
1931 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
1934 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
1937 The 1944-09-17 transition was at 03:00, not 01:00. This
1938 particular change is taken from Italian law as INRiM's table,
1939 (which says 02:00) appears to have a typo here. Also, keep the
1940 1944-04-03 transition for Europe/Rome, as Rome was controlled by
1943 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
1948 The code should now be buildable on AmigaOS merely by setting the
1949 appropriate Makefile variables. (From a patch by Carsten Larsen.)
1952 Release 2016h - 2016-10-19 23:17:57 -0700
1954 Changes to future timestamps
1956 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
1957 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
1958 future fall transitions will be on the last Saturday of October
1959 at 01:00, which is consistent with predicted spring transitions
1960 on the last Saturday of March. (Thanks to Tim Parenti.)
1962 Changes to past timestamps
1964 In Turkey, transitions in 1986-1990 were at 01:00 standard time
1965 not at 02:00, and the spring 1994 transition was on March 20, not
1966 March 27. (Thanks to Kıvanç Yazan.)
1968 Changes to past and future time zone abbreviations
1970 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
1971 instead of alphabetic ones like "IST" and "LKT". Various
1972 English-language sources use "IST", "LKT" and "SLST", with no
1973 working consensus. (Usage of "SLST" mentioned by Sadika
1978 zic no longer mishandles relativizing file names when creating
1979 symbolic links like /etc/localtime, when these symbolic links
1980 are outside the usual directory hierarchy. This fixes a bug
1981 introduced in 2016g. (Problem reported by Andreas Stieger.)
1983 Changes to build procedure
1985 New rules 'traditional_tarballs' and 'traditional_signatures' for
1986 building just the traditional-format distribution. (Requested by
1989 The file 'version' is now put into the tzdata tarball too.
1990 (Requested by Howard Hinnant.)
1992 Changes to documentation and commentary
1994 The 'Theory' file now has a section on interface stability.
1995 (Requested by Paul Koning.) It also mentions features like
1996 tm_zone and localtime_rz that have long been supported by the
1999 tz-link.htm has improved coverage of time zone boundaries suitable
2000 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
2003 The US commentary now mentions Allen and the "day of two noons".
2005 The Fiji commentary mentions the government's 2016-10-03 press
2006 release. (Thanks to Raymond Kumar.)
2009 Release 2016g - 2016-09-13 08:56:38 -0700
2011 Changes to future timestamps
2013 Turkey switched from EET/EEST (+02/+03) to permanent +03,
2014 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
2015 than an invented abbreviation for the new time.
2017 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
2018 (Thanks to Tim Parenti.)
2020 Changes to past timestamps
2022 For America/Los_Angeles, spring-forward transition times have been
2023 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2026 For zones using Soviet time on 1919-07-01, transitions to UT-based
2027 time were at 00:00 UT, not at 02:00 local time. The affected
2028 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2029 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2031 Changes to past and future time zone abbreviations
2033 The Factory zone now uses the time zone abbreviation -00 instead
2034 of a long English-language string, as -00 is now the normal way to
2035 represent an undefined time zone.
2037 Several zones in Antarctica and the former Soviet Union, along
2038 with zones intended for ships at sea that cannot use POSIX TZ
2039 strings, now use numeric time zone abbreviations instead of
2040 invented or obsolete alphanumeric abbreviations. The affected
2041 zones are Antarctica/Casey, Antarctica/Davis,
2042 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2043 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2044 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2045 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2046 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2047 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2048 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2049 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2050 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2051 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2052 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2053 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2054 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2055 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2056 was replaced by +05, whereas MSK and MSD were kept as they are not
2057 our invention and are widely used.
2059 Changes to zone names
2061 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2062 (Thanks to David Massoud.)
2066 zic no longer generates binary files containing POSIX TZ-like
2067 strings that disagree with the local time type after the last
2068 explicit transition in the data. This fixes a bug with
2069 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2070 on the reference platform. (Thanks to Alexander Belopolsky for
2071 reporting the bug and suggesting a way forward.)
2073 If the installed localtime and/or posixrules files are symbolic
2074 links, zic now keeps them symbolic links when updating them, for
2075 compatibility with platforms like OpenSUSE where other programs
2076 configure these files as symlinks.
2078 zic now avoids hard linking to symbolic links, avoids some
2079 unnecessary mkdir and stat system calls, and uses shorter file
2082 zdump has a new -i option to generate transitions in a
2083 more-compact but still human-readable format. This option is
2084 experimental, and the output format may change in future versions.
2085 (Thanks to Jon Skeet for suggesting that an option was needed,
2086 and thanks to Tim Parenti and Chris Rovick for further comments.)
2088 Changes to build procedure
2090 An experimental distribution format is available, in addition
2091 to the traditional format which will continue to be distributed.
2092 The new format is a tarball tzdb-VERSION.tar.lz with signature
2093 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2094 tzdb-VERSION containing the code and data of the traditional
2095 two-tarball format, along with extra data that may be useful.
2096 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2097 for comments about the experimental format.)
2099 The release version number is now more accurate in the usual case
2100 where releases are built from a Git repository. For example, if
2101 23 commits and some working-file changes have been made since
2102 release 2016g, the version number is now something like
2103 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2104 Tagged releases use the same version number format as before,
2105 e.g., '2016g'. To support the more-accurate version number, its
2106 specification has moved from a line in the Makefile to a new
2107 source file 'version'.
2109 The experimental distribution contains a file to2050.tzs that
2110 contains what should be the output of 'zdump -i -c 2050' on
2111 primary zones. If this file is available, 'make check' now checks
2112 that zdump generates this output.
2114 'make check_web' now works on Fedora-like distributions.
2116 Changes to documentation and commentary
2118 tzfile.5 now documents the new restriction on POSIX TZ-like
2119 strings that is now implemented by zic.
2121 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2122 (Thanks to Alexander Belopolsky.)
2124 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2125 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2126 description of Java 8 has been brought up to date (thanks to
2127 Stephen Colebourne). Its description of local time on Mars has
2128 been updated to match current practice, and URLs have been updated
2129 and some obsolete ones removed.
2132 Release 2016f - 2016-07-05 16:26:51 +0200
2134 Changes affecting future timestamps
2136 The Egyptian government changed its mind on short notice, and
2137 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2138 (Thanks to Mina Samuel.)
2140 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2141 (Thanks to Stepan Golosunov.)
2143 Changes to past and future timestamps
2145 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2146 abbreviations instead of invented ones.
2148 Changes affecting past timestamps
2150 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2151 (Thanks to Stepan Golosunov.)
2154 Release 2016e - 2016-06-14 08:46:16 -0700
2156 Changes affecting future timestamps
2158 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2159 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2160 For future years, guess April's last Thursday to October's last
2161 Thursday except for Ramadan.
2163 Changes affecting past timestamps
2165 Locations while uninhabited now use '-00', not 'zzz', as a
2166 placeholder time zone abbreviation. This is inspired by Internet
2167 RFC 3339 and is more consistent with numeric time zone
2168 abbreviations already used elsewhere. The change affects several
2169 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2170 1920 and Antarctica/Troll before 2005.
2172 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2173 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2177 zic now outputs a dummy transition at time 2**31 - 1 in zones
2178 whose POSIX-style TZ strings contain a '<'. This mostly works
2179 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2180 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2182 Changes affecting documentation and commentary
2184 tz-link.htm says why governments should give plenty of notice for
2185 time zone or DST changes, and refers to Matt Johnson's blog post.
2187 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2190 Release 2016d - 2016-04-17 22:50:29 -0700
2192 Changes affecting future timestamps
2194 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2195 (Thanks to Alexander Krivenyshev for the heads-up.)
2197 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2198 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2200 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2201 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2202 at 02:00. (Thanks to Stepan Golosunov.)
2204 Changes affecting past timestamps
2206 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2207 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2208 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2209 the same change. (Thanks to Stepan Golosunov.)
2211 Russia and nearby locations had daylight-saving transitions on
2212 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2213 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2216 Many corrections to historical time in Kazakhstan from 1991
2217 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2218 invented time zone abbreviations with numeric abbreviations.
2220 Changes to commentary
2222 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2225 Release 2016c - 2016-03-23 00:51:27 -0700
2227 Changes affecting future timestamps
2229 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2231 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2232 Correa for the heads-up, and to Tim Parenti for corrections.)
2233 Guess that future transitions are August's and May's second
2234 Saturdays at 24:00 mainland time. Also, call the period from
2235 2014-09-07 through 2016-05-14 daylight saving time instead of
2236 standard time, as that seems more appropriate now.
2238 Changes affecting past timestamps
2240 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2241 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2242 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2243 (Thanks to Stepan Golosunov.)
2245 Changes to commentary
2247 Several updates and URLs for historical and proposed Russian changes.
2248 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2251 Release 2016b - 2016-03-12 17:30:14 -0800
2255 Starting with release 2016b, some data entries cause zic implementations
2256 derived from tz releases 2005j through 2015e to issue warnings like
2257 "time zone abbreviation differs from POSIX standard (+03)".
2258 These warnings should not otherwise affect zic's output and can safely be
2259 ignored on today's platforms, as the warnings refer to a restriction in
2260 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2261 warnings is to upgrade to zic derived from tz releases 2015f and later.
2263 Changes affecting future timestamps
2265 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2266 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2267 2016-03-27 at 02:00 local time. They need distinct zones since their
2268 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2269 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2270 and local time. The Astrakhan change is already official; the others have
2271 passed the first reading in the State Duma and are extremely likely.
2272 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2273 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2274 and Stepan Golosunov for followup.)
2276 As a trial of a new system that needs less information to be made up,
2277 the new zones use numeric time zone abbreviations like "+04"
2278 instead of invented abbreviations like "ASTT".
2280 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2283 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2284 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2285 Saturday at 01:00, not March's last Friday at 24:00.
2287 Changes affecting past timestamps
2289 Europe/Chisinau observed DST during 1990, and switched from +04 to
2290 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2291 (Thanks to Stepan Golosunov.)
2293 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2294 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2298 tzselect's diagnostics and checking, and checktab.awk's checking,
2299 have been improved. (Thanks to J William Piggott.)
2301 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2303 tzselect now tests Julian-date TZ settings more accurately.
2304 (Thanks to J William Piggott.)
2306 Changes to commentary
2308 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2310 tzselect again limits its menu comments so that menus fit on a
2311 24×80 alphanumeric display.
2313 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2315 In the Theory file, the description of possible time zone abbreviations in
2316 tzdata has been cleaned up, as the old description was unclear and
2317 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2320 Release 2016a - 2016-01-26 23:28:02 -0800
2322 Changes affecting future timestamps
2324 America/Cayman will not observe daylight saving this year after all.
2325 Revert our guess that it would. (Thanks to Matt Johnson.)
2327 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2328 (Thanks to Alexander Krivenyshev.)
2330 Asia/Tehran now has DST predictions for the year 2038 and later,
2331 to be March 21 00:00 to September 21 00:00. This is likely better
2332 than predicting no DST, albeit off by a day every now and then.
2334 Changes affecting past and future timestamps
2336 America/Metlakatla switched from PST all year to AKST/AKDT on
2337 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2339 America/Santa_Isabel has been removed, and replaced with a
2340 backward compatibility link to America/Tijuana. Its contents were
2341 apparently based on a misreading of Mexican legislation.
2343 Changes affecting past timestamps
2345 Asia/Karachi's two transition times in 2002 were off by a minute.
2346 (Thanks to Matt Johnson.)
2348 Changes affecting build procedure
2350 An installer can now combine leap seconds with use of the backzone file,
2351 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2352 The old 'make posix_packrat' rule is now marked as obsolescent.
2353 (Thanks to Ian Abbott for an initial implementation.)
2355 Changes affecting documentation and commentary
2357 A new file LICENSE makes it easier to see that the code and data
2358 are mostly public-domain. (Thanks to James Knight.) The three
2359 non-public-domain files now use the current (3-clause) BSD license
2360 instead of older versions of that license.
2362 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2363 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2364 on editing tz source files (with a mention of Sublime zoneinfo,
2365 thanks to Gilmore Davidson).
2367 The Theory and asia files now mention the 2015 book "The Global
2368 Transformation of Time, 1870-1950", and cite a couple of reviews.
2370 The America/Chicago entry now documents the informal use of US
2371 central time in Fort Pierre, South Dakota. (Thanks to Rick
2372 McDermid, Matt Johnson, and Steve Jones.)
2375 Release 2015g - 2015-10-01 00:39:51 -0700
2377 Changes affecting future timestamps
2379 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2382 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2383 (Thanks to Alexander Krivenyshev.)
2385 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2386 (Thanks to Ken Rylander.)
2388 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2389 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2390 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2392 Changes affecting past timestamps
2394 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2396 Changes affecting code
2398 localtime no longer mishandles America/Anchorage after 2037.
2399 (Thanks to Bradley White for reporting the bug.)
2401 On hosts with signed 32-bit time_t, localtime no longer mishandles
2402 Pacific/Fiji after 2038-01-16 14:00 UTC.
2404 The localtime module allows the variables 'timezone', 'daylight',
2405 and 'altzone' to be in common storage shared with other modules,
2406 and declares them in case the system <time.h> does not.
2407 (Problems reported by Kees Dekker.)
2409 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2410 This simplifies the code and is consistent with zdump.c.
2411 (Problem reported by Christos Zoulas.)
2413 Changes affecting documentation
2415 The tzfile man page now documents that transition times denote the
2416 starts (not the ends) of the corresponding time periods.
2417 (Ambiguity reported by Bill Seymour.)
2420 Release 2015f - 2015-08-10 18:06:56 -0700
2422 Changes affecting future timestamps
2424 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2425 The abbreviation remains "KST". (Thanks to Robert Elz.)
2427 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2430 Changes affecting past and future timestamps
2432 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2433 (Thanks to Roman Tudos.)
2435 Changes affecting data format and code
2437 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2438 field of a Rule line should now be '-'; the old values 'even',
2439 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2440 Although the implementation has not changed, these features do not
2441 work in the default installation, they are not used in the data,
2442 and they are now considered obsolescent.
2444 zic now checks that two rules don't take effect at the same time.
2445 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2446 simultaneity are now documented.
2448 The two characters '%z' in a zone format now stand for the UT
2449 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2450 five hours and thirty minutes ahead. This better supports time
2451 zone abbreviations conforming to POSIX.1-2001 and later.
2453 Changes affecting installed data files
2455 Comments for America/Halifax and America/Glace_Bay have been improved.
2456 (Thanks to Brian Inglis.)
2458 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2459 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2460 installed data files for Europe/Simferopol and Europe/Tallinn.
2461 It does not affect timestamps. (Thanks to Howard Hinnant.)
2463 Changes affecting code
2465 zdump and zic no longer warn about valid time zone abbreviations
2468 Some Visual Studio 2013 warnings have been suppressed.
2469 (Thanks to Kees Dekker.)
2471 'date' no longer sets the time of day and its -a, -d, -n and -t
2472 options have been removed. Long obsolescent, the implementation
2473 of these features had porting problems. Builders no longer need
2474 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2475 (Thanks to Kees Dekker for pointing out the problem.)
2477 Changes affecting documentation
2479 The Theory file mentions naming issues earlier, as these seem to be
2480 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2482 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2484 Mention that Herbert Samuel introduced the term "Summer Time".
2487 Release 2015e - 2015-06-13 10:56:02 -0700
2489 Changes affecting future timestamps
2491 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2492 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2494 Assume Cayman Islands will observe DST starting next year, using US rules.
2495 Although it isn't guaranteed, it is the most likely.
2497 Changes affecting data format
2499 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2500 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2502 Changes affecting code
2504 When displaying data, tzselect converts it to the current locale's
2505 encoding if the iconv command works. (Problem reported by random832.)
2507 tzselect no longer mishandles Dominica, fixing a bug introduced
2508 in Release 2014f. (Problem reported by Owen Leibman.)
2510 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2511 This fixes a bug introduced in Release 2014f.
2512 (Problem reported by Leonardo Chiquitto.)
2515 Release 2015d - 2015-04-24 08:09:46 -0700
2517 Changes affecting future timestamps
2519 Egypt will not observe DST in 2015 and will consider canceling it
2520 permanently. For now, assume no DST indefinitely.
2521 (Thanks to Ahmed Nazmy and Tim Parenti.)
2523 Changes affecting past timestamps
2525 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2526 1966-07-01. Also, Yukon's time zone history is documented better.
2527 (Thanks to Brian Inglis and Dennis Ferguson.)
2529 Change affecting past and future time zone abbreviations
2531 The abbreviations for Hawaii-Aleutian standard and daylight times
2532 have been changed from HAST/HADT to HST/HDT, as per US Government
2533 Printing Office style. This affects only America/Adak since 1983,
2534 as America/Honolulu was already using the new style.
2536 Changes affecting code
2538 zic has some minor performance improvements.
2541 Release 2015c - 2015-04-11 08:55:55 -0700
2543 Changes affecting future timestamps
2545 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2546 not 00:00 on April's last Friday. 2015's transition will therefore be on
2547 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2548 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2550 Changes affecting past timestamps
2552 The following changes affect some pre-1991 Chile-related timestamps
2553 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2555 The 1910 transition was January 10, not January 1.
2557 The 1918 transition was September 10, not September 1.
2559 The UT -04 time observed from 1932 to 1942 is now considered to
2560 be standard time, not year-round DST.
2562 Santiago observed DST (UT -03) from 1946-07-15 through
2563 1946-08-31, then reverted to standard time, then switched to -05
2566 Assume transitions before 1968 were at 00:00, since we have no data
2569 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2570 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2572 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2573 and omit all transitions on Pacific/Easter from 1942 through 1946
2574 since we have no data suggesting that they existed.
2576 One more zone has been turned into a link, as it differed
2577 from an existing zone only for older timestamps. As usual,
2578 this change affects UT offsets in pre-1970 timestamps only.
2579 The zone's old contents have been moved to the 'backzone' file.
2580 The affected zone is America/Montreal.
2582 Changes affecting commentary
2584 Mention the TZUpdater tool.
2586 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2589 Release 2015b - 2015-03-19 23:28:11 -0700
2591 Changes affecting future timestamps
2593 Mongolia will start observing DST again this year, from the last
2594 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2595 (Thanks to Ganbold Tsagaankhuu.)
2597 Palestine will start DST on March 28, not March 27. Also,
2598 correct the fall 2014 transition from September 26 to October 24.
2599 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2601 Changes affecting past timestamps
2603 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2604 regression. (Thanks to Stuart Bishop for reporting the problem.)
2606 Some more zones have been turned into links, when they differed
2607 from existing zones only for older timestamps. As usual,
2608 these changes affect UT offsets in pre-1970 timestamps only.
2609 Their old contents have been moved to the 'backzone' file.
2610 The affected zones are: America/Antigua, America/Cayman,
2611 Pacific/Midway, and Pacific/Saipan.
2613 Changes affecting time zone abbreviations
2615 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2618 Changes affecting code
2620 Fix integer overflow bug in reference 'mktime' implementation.
2621 (Problem reported by Jörg Richter.)
2623 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2624 to be used in the same executable as standard-library time_t functions.
2625 (Problems reported by Bradley White.)
2627 Changes affecting commentary
2629 Cite the recent Mexican decree changing Quintana Roo's time zone.
2630 (Thanks to Carlos Raúl Perasso.)
2632 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2634 Update info about Mars time.
2637 Release 2015a - 2015-01-29 22:35:20 -0800
2639 Changes affecting future timestamps
2641 The Mexican state of Quintana Roo, represented by America/Cancun,
2642 will shift from Central Time with DST to Eastern Time without DST
2643 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2645 Chile will not change clocks in April or thereafter; its new standard time
2646 will be its old daylight saving time. This affects America/Santiago,
2647 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2649 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2650 (Thanks to Tim Parenti.)
2652 Changes affecting past timestamps
2654 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2655 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2656 Shanks about time in Iceland between 1837 and 1908.
2658 Some more zones have been turned into links, when they differed
2659 from existing zones only for older timestamps. As usual,
2660 these changes affect UT offsets in pre-1970 timestamps only.
2661 Their old contents have been moved to the 'backzone' file.
2662 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2665 Changes affecting code
2667 tzalloc now scrubs time zone abbreviations compatibly with the way
2668 that tzset always has, by replacing invalid bytes with '_' and by
2669 shortening too-long abbreviations.
2671 tzselect ports to POSIX awk implementations, no longer mishandles
2672 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2673 settings to the user. (Thanks to Stefan Kuhn.)
2675 Changes affecting build procedure
2677 'make check' now checks for links to links in the data.
2678 One such link (for Africa/Asmera) has been fixed.
2679 (Thanks to Stephen Colebourne for pointing out the problem.)
2681 Changes affecting commentary
2683 The leapseconds file commentary now mentions the expiration date.
2684 (Problem reported by Martin Burnicki.)
2686 Update Mexican Library of Congress URL.
2689 Release 2014j - 2014-11-10 17:37:11 -0800
2691 Changes affecting current and future timestamps
2693 Turks & Caicos' switch from US eastern time to UT -04 year-round
2694 did not occur on 2014-11-02 at 02:00. It's currently scheduled
2695 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
2697 Changes affecting past timestamps
2699 Many pre-1989 timestamps have been corrected for Asia/Seoul and
2700 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2701 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
2702 longer guess that Pyongyang mimicked Seoul time after World War II,
2703 as this is politically implausible.
2705 Some more zones have been turned into links, when they differed
2706 from existing zones only for older timestamps. As usual,
2707 these changes affect UT offsets in pre-1970 timestamps only.
2708 Their old contents have been moved to the 'backzone' file.
2709 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2710 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2711 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2714 Changes affecting commentary
2716 The commentary is less enthusiastic about Shanks as a source,
2717 and is more careful to distinguish UT from UTC.
2720 Release 2014i - 2014-10-21 22:04:57 -0700
2722 Changes affecting future timestamps
2724 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2725 (Thanks to Ken Rylander for the heads-up.) Guess that future
2726 years will use a similar pattern.
2728 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2729 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2730 (Thanks to Kiley Walbom for the heads-up.)
2732 Changes affecting time zone abbreviations
2734 Since Belarus is not changing its clocks even though Moscow is,
2735 the time zone abbreviation in Europe/Minsk is changing from FET
2736 to its more-traditional value MSK on 2014-10-26 at 01:00.
2737 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2739 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2740 Indochina, to distinguish it better from ICT (+07).
2742 Changes affecting past timestamps
2744 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2745 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2746 authoritative book). Asia/Ho_Chi_Minh has been added to
2747 zone1970.tab, to give tzselect users in Vietnam two choices,
2748 since north and south Vietnam disagreed after our 1970 cutoff.
2750 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2751 they differed from existing zones only for older timestamps. As
2752 usual, these changes affect pre-1970 timestamps only. Their old
2753 contents have been moved to the 'backzone' file.
2755 Changes affecting code
2757 The time-related library functions now set errno on failure, and
2758 some crashes in the new tzalloc-related library functions have
2759 been fixed. (Thanks to Christos Zoulas for reporting most of
2760 these problems and for suggesting fixes.)
2762 If USG_COMPAT is defined and the requested timestamp is standard time,
2763 the tz library's localtime and mktime functions now set the extern
2764 variable timezone to a value appropriate for that timestamp; and
2765 similarly for ALTZONE, daylight saving time, and the altzone variable.
2766 This change is a companion to the tzname change in 2014h, and is
2767 designed to make timezone and altzone more compatible with tzname.
2769 The tz library's functions now set errno to EOVERFLOW if they fail
2770 because the result cannot be represented. ctime and ctime_r now
2771 return NULL and set errno when a timestamp is out of range, rather
2772 than having undefined behavior.
2774 Some bugs associated with the new 2014g functions have been fixed.
2775 This includes a bug that largely incapacitated the new functions
2776 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
2777 It also includes some uses of uninitialized variables after tzalloc.
2778 The new code uses the standard type 'ssize_t', which the Makefile
2779 now gives porting advice about.
2781 Changes affecting commentary
2783 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2786 Release 2014h - 2014-09-25 18:59:03 -0700
2788 Changes affecting past timestamps
2790 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2792 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2793 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
2795 Some more zones have been turned into links, when they differed
2796 from existing zones only for older timestamps. As usual,
2797 these changes affect UT offsets in pre-1970 timestamps only.
2798 Their old contents have been moved to the 'backzone' file.
2799 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2800 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2801 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2803 Changes affecting code
2805 zdump -V and -v now output gmtoff= values on all platforms,
2806 not merely on platforms defining TM_GMTOFF.
2808 The tz library's localtime and mktime functions now set tzname to a value
2809 appropriate for the requested timestamp, and zdump now uses this
2810 on platforms not defining TM_ZONE, fixing a 2014g regression.
2811 (Thanks to Tim Parenti for reporting the problem.)
2813 The tz library no longer sets tzname if localtime or mktime fails.
2815 zdump -c no longer mishandles transitions near year boundaries.
2816 (Thanks to Tim Parenti for reporting the problem.)
2818 An access to uninitialized data has been fixed.
2819 (Thanks to Jörg Richter for reporting the problem.)
2821 When THREAD_SAFE is defined, the code ports to the C11 memory model.
2822 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2823 and two threads race to initialize data used by gmtime-like functions.
2824 (Thanks to Andy Heninger for reporting the problems.)
2826 Changes affecting build procedure
2828 'make check' now checks better for properly-sorted data.
2830 Changes affecting documentation and commentary
2832 zdump's gmtoff=N output is now documented, and its isdst=D output
2833 is now documented to possibly output D values other than 0 or 1.
2835 zdump -c's treatment of years is now documented to use the
2836 Gregorian calendar and Universal Time without leap seconds,
2837 and its behavior at cutoff boundaries is now documented better.
2838 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2840 Programs are now documented to use the proleptic Gregorian calendar.
2841 (Thanks to Alan Barrett for the suggestion.)
2843 Fractional-second GMT offsets have been documented for civil time
2844 in 19th-century Chennai, Jakarta, and New York.
2847 Release 2014g - 2014-08-28 12:31:23 -0700
2849 Changes affecting future timestamps
2851 Turks & Caicos is switching from US eastern time to UT -04
2852 year-round, modeled as a switch on 2014-11-02 at 02:00.
2853 [As noted in 2014j, this switch was later delayed.]
2855 Changes affecting past timestamps
2857 Time in Russia or the USSR before 1926 or so has been corrected by
2858 a few seconds in the following zones: Asia/Irkutsk,
2859 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
2860 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
2861 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
2862 Vladimir Karpinsky.)
2864 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
2865 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
2866 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
2867 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
2868 (Thanks to Stephen Colebourne for pointing to the decree.)
2870 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
2872 A new file 'backzone' contains data which may appeal to
2873 connoisseurs of old timestamps, although it is out of scope for
2874 the tz database, is often poorly sourced, and contains some data
2875 that is known to be incorrect. The new file is not recommended
2876 for ordinary use and its entries are not installed by default.
2877 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
2878 Isle of Man entries.)
2880 Some more zones have been turned into links, when they differed
2881 from existing zones only for older timestamps. As usual,
2882 these changes affect UT offsets in pre-1970 timestamps only.
2883 Their old contents have been moved to the 'backzone' file.
2884 The affected zones are: Africa/Bangui, Africa/Brazzaville,
2885 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
2886 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
2888 Changes affecting code
2890 Unless NETBSD_INSPIRED is defined to 0, the tz library now
2891 supplies functions for creating and using objects that represent
2892 timezones. The new functions are tzalloc, tzfree, localtime_rz,
2893 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
2894 time2posix_z. They are intended for performance: for example,
2895 localtime_rz (unlike localtime_r) is trivially thread-safe without
2896 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
2897 functions, and to Alan Barrett and Jonathan Lennox for helping to
2900 zdump now builds with the tz library unless USE_LTZ is defined to 0,
2901 This lets zdump use tz features even if the system library lacks them.
2902 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
2903 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
2905 zdump now uses localtime_rz if available, as it's significantly faster,
2906 and it can help zdump better diagnose invalid timezone names.
2907 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
2908 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
2909 not available, zdump now uses localtime_r and tzset if available,
2910 as this is a bit cleaner and faster than plain localtime. Compile
2911 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
2912 lacks these two functions.
2914 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
2915 Although not needed for tz's own applications, which are single-threaded,
2916 this supports POSIX better if the tz library is used in multithreaded apps.
2918 Some crashes have been fixed when zdump or the tz library is given
2919 invalid or outlandish input.
2921 The tz library no longer mishandles leap seconds on platforms with
2922 unsigned time_t in timezones that lack ordinary transitions after 1970.
2924 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
2925 already defined, to make it easier to configure on common platforms.
2926 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
2928 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
2929 assumes that reading uninitialized memory yields garbage values
2930 but does not cause other problems such as traps.
2932 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
2933 more likely to guess right for ambiguous timestamps near
2934 transitions where tm_isdst does not change.
2936 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
2937 strftime_l for compatibility with recent versions of POSIX.
2938 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
2939 to 1 on recent POSIX versions, and to 0 otherwise.
2941 tzselect -c now uses a hybrid distance measure that works better
2942 in Africa. (Thanks to Alan Barrett for noting the problem.)
2944 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
2945 or when time_tz is defined.
2947 When HAVE_UTMPX_H is set the 'date' command now builds on systems
2948 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
2949 the date it updates the wtmpx file if _PATH_WTMPX is defined.
2950 This affects GNU/Linux and similar systems.
2952 For easier maintenance later, some C code has been simplified,
2953 some lint has been removed, and the code has been tweaked so that
2954 plain 'make' is more likely to work.
2956 The C type 'bool' is now used for boolean values, instead of 'int'.
2958 The long-obsolete LOCALE_HOME code has been removed.
2960 The long-obsolete 'gtime' function has been removed.
2962 Changes affecting build procedure
2964 'zdump' no longer links in ialloc.o, as it's not needed.
2966 'make check_time_t_alternatives' no longer assumes GNU diff.
2968 Changes affecting distribution tarballs
2970 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
2971 the tzdata tarball instead of the tzcode tarball, since they help
2972 maintain the data. The NEWS and Theory files are now also
2973 distributed in the tzdata tarball, as they're relevant for data.
2974 (Thanks to Alan Barrett for pointing this out.) Also, the
2975 leapseconds.awk file is no longer distributed in the tzcode
2976 tarball, since it belongs in the tzdata tarball (where 2014f
2977 inadvertently also distributed it).
2979 Changes affecting documentation and commentary
2981 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
2982 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
2985 The man pages have been updated to use function prototypes,
2986 to document thread-safe variants like localtime_r, and to document
2987 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
2990 The fields in Link lines have been renamed to be more descriptive
2991 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
2992 and LINK-TO has become LINK-NAME.
2994 tz-link.htm mentions the IETF's tzdist working group; Windows
2995 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
2997 Some broken URLs have been fixed in the commentary. (Thanks to
3000 Commentary about Philippines DST has been updated, and commentary
3001 on pre-1970 time in India has been added.
3004 Release 2014f - 2014-08-05 17:42:36 -0700
3006 Changes affecting future timestamps
3008 Russia will subtract an hour from most of its time zones on 2014-10-26
3009 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
3010 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
3011 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
3012 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
3013 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
3014 (Europe/Samara) are not changing their clocks. The changed zones are
3015 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
3016 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
3017 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
3018 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
3019 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
3020 but not its UTC offset. Two zones are added: Asia/Chita (split
3021 from Asia/Yakutsk, and also with two hours subtracted) and
3022 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
3023 subtracted). (Thanks to Tim Parenti for much of the above.)
3025 Changes affecting time zone abbreviations
3027 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3028 and similarly for the other Australian zones. That is, for eastern
3029 standard and daylight saving time the abbreviations are AEST and AEDT
3030 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3031 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3032 This change does not affect UT offsets, only time zone abbreviations.
3033 (Thanks to Rich Tibbett and many others.)
3035 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3036 effective 2014-10-26 at 02:00 local time.
3038 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3039 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3041 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3042 Similarly, prefer EET/EEST for eastern European time in Russia.
3044 Change time zone abbreviations in (western) Samoa to use "ST" and
3045 "DT" suffixes, as this is more likely to match common practice.
3046 Prefix "W" to (western) Samoa time when its standard-time offset
3047 disagrees with that of American Samoa.
3049 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3051 Time zone abbreviations have been updated for Japan's two time
3052 zones used 1896-1937. JWST now stands for Western Standard
3053 Time, and JCST for Central Standard Time (formerly this was CJT).
3054 These abbreviations are now used for time in Korea, Taiwan,
3055 and Sakhalin while controlled by Japan.
3057 Changes affecting past timestamps
3059 China's five zones have been simplified to two, since the post-1970
3060 differences in the other three seem to have been imaginary. The
3061 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3062 removed; backwards-compatibility links still work, albeit with
3063 different behaviors for timestamps before May 1980. Asia/Urumqi's
3064 1980 transition to UT +08 has been removed, so that it is now at
3065 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3066 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3068 Some zones have been turned into links, when they differed from existing
3069 zones only for older UT offsets where data entries were likely invented.
3070 These changes affect UT offsets in pre-1970 timestamps only. This is
3071 similar to the change in release 2013e, except this time for western
3072 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3073 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3074 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3075 Atlantic/St_Helena. This also affects the backwards-compatibility
3076 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3077 Tim Parenti, and David Patte for reporting problems in earlier
3078 versions of this change.)
3080 Asia/Shanghai's pre-standard-time UT offset has been changed from
3081 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3082 transition to standard time has been changed from 1928 to 1901.
3084 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3085 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3086 In 1946 it observed DST from 05-15 through 09-30; in 1947
3087 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3088 (Thanks to Yu-Cheng Chuang.)
3090 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3092 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3093 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3095 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3096 period from 1911 to 1950.
3098 Pacific/Chatham has been changed to New Zealand standard time plus
3099 45 minutes for the period before 1957, reflecting a 1956 remark in
3100 the New Zealand parliament.
3102 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3103 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3104 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3105 not 04-06 at 02:00; and there was no DST in 1920.
3107 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3109 Time in Russia before 1927 or so has been corrected by a few seconds in
3110 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3111 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3112 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3113 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3115 Changes affecting data format
3117 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3118 The new file's extended format allows multiple country codes per zone.
3119 The older file is still installed but is deprecated; its format is
3120 not changing and it will still be distributed for a while, but new
3121 applications should use the new file.
3123 The new file format simplifies maintenance of obscure locations.
3124 To test this, it adds coverage for the Crozet Islands and the
3125 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3127 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3128 It is still ASCII now, but commentary about the switch has been added.
3129 The new file 'zone1970.tab' already uses UTF-8.
3131 Changes affecting code
3133 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3134 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3136 'zic' no longer mishandles input when ignoring case in locales that
3137 are not compatible with English, e.g., unibyte Turkish locales when
3138 compiled with HAVE_GETTEXT.
3140 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3141 they no longer use ASCII '-' as if it were a dash.
3143 'zic' now rejects output file names that contain '.' or '..' components.
3144 (Thanks to Tim Parenti for reporting the problem.)
3146 'zic -v' now warns about output file names that do not follow
3147 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3148 David Olson for starting the ball rolling on this.)
3150 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3152 Changes affecting build procedure
3154 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3155 (Thanks to John Cochran.)
3157 Changes affecting documentation and commentary
3159 The 'Theory' file documents legacy names, the longstanding
3160 exceptions to the POSIX-inspired file name rules.
3162 The 'zic' documentation clarifies the role of time types when
3163 interpreting dates. (Thanks to Arthur David Olson.)
3165 Documentation and commentary now prefer UTF-8 to US-ASCII,
3166 allowing the use of proper accents in foreign words and names.
3167 Code and data have not changed because of this. (Thanks to
3168 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3171 Non-HTML documentation and commentary now use plain-text URLs instead of
3172 HTML insertions, and are more consistent about bracketing URLs when they
3173 are not already surrounded by white space. (Thanks to suggestions by
3176 There is new commentary about Xujiahui Observatory, the five time-zone
3177 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3178 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3179 warlord Jin Shuren in the data.
3181 Commentary about the coverage of each Russian zone has been standardized.
3182 (Thanks to Tim Parenti.)
3184 There is new commentary about contemporary timekeeping in Ethiopia.
3186 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3188 There is new commentary about time in Poland in 1919.
3190 Proper credit has been given to DST inventor George Vernon Hudson.
3192 Commentary about time in Metlakatla, AK and Resolute, NU has been
3193 improved, with a new source for the former.
3195 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3198 Commentary about permanent Antarctic bases has been updated.
3200 Several typos have been corrected. (Thanks to Tim Parenti for
3201 contributing some of these fixes.)
3203 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3204 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3205 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3206 (Thanks to a heads-up from Dirkjan Ochtman.)
3208 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3209 have been removed. These obsolescent US Naval Observatory entries were no
3210 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3213 Release 2014e - 2014-06-12 21:53:52 -0700
3215 Changes affecting near-future timestamps
3217 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3218 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3219 switch to standard time at 24:00 the last Thursday before Ramadan, and
3220 back to DST at 00:00 the first Friday after Ramadan.
3222 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3223 to Milamber Space Network.) Guess that from 2015 on Morocco will
3224 temporarily switch to standard time at 03:00 the last Saturday before
3225 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3227 Changes affecting past timestamps
3229 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3230 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3231 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3232 in 1991. (Thanks to Hank W. for reporting the problems.)
3234 Changes affecting commentary
3236 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3237 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3238 removes stale pointers to World Time Explorer and WORLDTIME.
3241 Release 2014d - 2014-05-27 21:34:40 -0700
3243 Changes affecting code
3245 zic no longer generates files containing timestamps before the Big Bang.
3246 This works around GNOME glib bug 878
3247 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3248 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3249 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3251 Changes affecting documentation
3253 tz-link.htm now mentions GNOME.
3256 Release 2014c - 2014-05-13 07:44:13 -0700
3258 Changes affecting near-future timestamps
3260 Egypt observes DST starting 2014-05-15 at 24:00.
3261 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3262 Details have not been announced, except that DST will not be observed
3263 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3264 Morocco, and that Egypt's future spring and fall transitions will be the
3265 same as 2010 when it last observed DST, namely April's last Friday at
3266 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3267 that Ramadan transitions will be at 00:00 standard time.
3269 Changes affecting code
3271 zic now generates transitions for minimum time values, eliminating guesswork
3272 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3274 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3276 Changes affecting commentary and documentation
3278 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3281 Release 2014b - 2014-03-24 21:28:50 -0700
3283 Changes affecting near-future timestamps
3285 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3286 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3288 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3289 Bengt-Inge Larsson.) This is currently an approximation; a better version
3290 will require the zic and localtime fixes mentioned below, and the plan is
3291 to wait for a while until at least the zic fixes propagate.
3293 Changes affecting code
3295 'zic' and 'localtime' no longer reject locations needing four transitions
3296 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3297 Also, 'zic' avoids some unlikely failures due to integer overflow.
3299 Changes affecting build procedure
3301 'make check' now detects Rule lines defined but never used.
3302 The NZAQ rules, an instance of this problem, have been removed.
3304 Changes affecting commentary and documentation
3306 Fix Tuesday/Thursday typo in description of time in Israel.
3307 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3309 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3310 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3311 library supports them.
3313 Add comments about Johnston Island time in the 1960s.
3314 (Thanks to Lyle McElhaney.)
3316 Morocco's 2014 DST start will be as predicted.
3317 (Thanks to Sebastien Willemijns.)
3320 Release 2014a - 2014-03-07 23:30:29 -0800
3322 Changes affecting near-future timestamps
3324 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3325 the heads-up, and to Tim Parenti for simplifying the update.)
3327 Changes affecting past timestamps
3329 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
3330 (Thanks to Steffen Thorsen.)
3332 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3333 (not 1992-01-01), and observed DST during the entire next winter.
3334 (Thanks to Vladimir in Moscow via Alois Treindl.)
3336 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3337 (Thanks to Avigdor Finkelstein.)
3339 Changes affecting code
3341 A uninitialized-storage bug in 'localtime' has been fixed.
3342 (Thanks to Logan Chien.)
3344 Changes affecting the build procedure
3346 The settings for 'make check_web' now default to Ubuntu 13.10.
3348 Changes affecting commentary and documentation
3350 The boundary of the US Pacific time zone is given more accurately.
3351 (Thanks to Alan Mintz.)
3353 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3355 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3357 Better descriptions of countries with same time zone history as
3358 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3360 Several changes affect tz-link.htm, the main web page.
3362 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3365 Mention xCal (Internet RFC 6321) and jCal.
3367 Microsoft has some support for tz database names.
3369 CLDR data formats include both XML and JSON.
3371 Mention Maggiolo's map of solar vs standard time.
3372 (Thanks to Arthur David Olson.)
3374 Mention TZ4Net. (Thanks to Matt Johnson.)
3376 Mention the timezone-olson Haskell package.
3378 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3380 Remove moribund links to daylight-savings-time.info and to
3381 Simple Timer + Clocks.
3383 Update two links. (Thanks to Oscar van Vlijmen.)
3385 Fix some formatting glitches, e.g., remove random newlines from
3386 abbr elements' title attributes.
3389 Release 2013i - 2013-12-17 07:25:23 -0800
3391 Changes affecting near-future timestamps:
3393 Jordan switches back to standard time at 00:00 on December 20, 2013.
3394 The 2006-2011 transition schedule is planned to resume in 2014.
3395 (Thanks to Steffen Thorsen.)
3397 Changes affecting past timestamps:
3399 In 2004, Cuba began DST on March 28, not April 4.
3400 (Thanks to Steffen Thorsen.)
3402 Changes affecting code
3404 The compile-time flag NOSOLAR has been removed, as nowadays the
3405 benefit of slightly shrinking runtime table size is outweighed by the
3406 cost of disallowing potential future updates that exceed old limits.
3408 Changes affecting documentation and commentary
3410 The files solar87, solar88, and solar89 are no longer distributed.
3411 They were a negative experiment - that is, a demonstration that
3412 tz data can represent solar time only with some difficulty and error.
3413 Their presence in the distribution caused confusion, as Riyadh
3414 civil time was generally not solar time in those years.
3416 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3419 Release 2013h - 2013-10-25 15:32:32 -0700
3421 Changes affecting current and future timestamps:
3423 Libya has switched its UT offset back to +02 without DST, instead
3424 of +01 with DST. (Thanks to Even Scharning.)
3426 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3427 (Thanks to Gwillim Law.)
3429 Changes affecting future timestamps:
3431 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3432 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3433 (Thanks to Steffen Thorsen.)
3435 Add entries for DST transitions in Morocco in the year 2038.
3436 This avoids some year-2038 glitches introduced in 2013g.
3437 (Thanks to Yoshito Umaoka for reporting the problem.)
3439 Changes affecting API
3441 The 'tzselect' command no longer requires the 'select' command,
3442 and should now work with /bin/sh on more platforms. It also works
3443 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3444 Patrick 'P. J.' McDermott and Alan Barrett.)
3446 Changes affecting code
3448 Fix localtime overflow bugs with 32-bit unsigned time_t.
3450 zdump no longer assumes sscanf returns maximal values on overflow.
3452 Changes affecting the build procedure
3454 The builder can specify which programs to use, if any, instead of
3455 'ar' and 'ranlib', and libtz.a is now built locally before being
3456 installed. (Thanks to Michael Forney.)
3458 A dependency typo in the 'zdump' rule has been fixed.
3459 (Thanks to Andrew Paprocki.)
3461 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3462 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3464 'make clean' no longer removes 'leapseconds', since it's
3465 host-independent and is part of the distribution.
3467 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3469 Changes affecting documentation and commentary
3471 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3472 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3474 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3475 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3476 longer maintained) and for old advisories. SOFA now does C.
3478 Release 2013g - 2013-09-30 21:08:26 -0700
3480 Changes affecting current and near-future timestamps
3482 Morocco now observes DST from the last Sunday in March to the last
3483 Sunday in October, not April to September respectively. (Thanks
3484 to Steffen Thorsen.)
3486 Changes affecting 'zic'
3488 'zic' now runs on platforms that lack both hard links and symlinks.
3489 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3490 Also, fix some bugs on platforms that lack hard links but have symlinks.
3492 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3493 to predict the far future, fixing a bug introduced in 2013e.
3495 Changes affecting the build procedure
3497 The 'leapseconds' file is again put into the tzdata tarball.
3498 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3499 Matt Burgess and Ian Abbott.) The timestamps of these and other
3500 dependent files in tarballs are adjusted more consistently.
3502 Changes affecting documentation and commentary
3504 The README file is now part of the data tarball as well as the code.
3505 It now states that files are public domain unless otherwise specified.
3506 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3507 Its details about the 1989 release moved to a place of honor near
3511 Release 2013f - 2013-09-24 23:37:36 -0700
3513 Changes affecting near-future timestamps
3515 Tocantins will very likely not observe DST starting this spring.
3516 (Thanks to Steffen Thorsen.)
3518 Jordan will likely stay at UT +03 indefinitely, and will not fall
3521 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3523 Changes affecting API
3525 The types of the global variables 'timezone' and 'altzone' (if present)
3526 have been changed back to 'long'. This is required for 'timezone'
3527 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3528 These variables were originally 'long' in the tz code, but were
3529 mistakenly changed to 'time_t' in 1987; nobody reported the
3530 incompatibility until now. The difference matters on x32, where
3531 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3533 Changes affecting the build procedure
3535 Avoid long strings in leapseconds.awk to work around a mawk bug.
3536 (Thanks to Cyril Baurand.)
3538 Changes affecting documentation and commentary
3540 New file 'NEWS' that contains release notes like this one.
3542 Paraguay's law does not specify DST transition time; 00:00 is customary.
3543 (Thanks to Waldemar Villamayor-Venialbo.)
3545 Minor capitalization fixes.
3547 Changes affecting version-control only
3549 The experimental GitHub repository now contains annotated and
3550 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3551 Releases are tagged starting with 2012e; earlier releases were
3552 done differently, and tags would either not have a simple name or
3553 not exactly match what was released.
3555 'make set-timestamps' is now simpler and a bit more portable.
3558 Release 2013e - 2013-09-19 23:50:04 -0700
3560 Changes affecting near-future timestamps
3562 This year Fiji will start DST on October 27, not October 20.
3563 (Thanks to David Wheeler for the heads-up.) For now, guess that
3564 Fiji will continue to spring forward the Sunday before the fourth
3567 Changes affecting current and future time zone abbreviations
3569 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3570 time zone abbreviations since 1932. (Thanks to George Ziegler,
3571 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3572 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3573 Asia/Makassar, and Asia/Pontianak.
3575 Use ART (UT -03, standard time), rather than WARST (also -03, but
3576 daylight saving time) for San Luis, Argentina since 2009.
3578 Changes affecting Godthåb timestamps after 2037 if version mismatch
3580 Allow POSIX-like TZ strings where the transition time's hour can
3581 range from -167 through 167, instead of the POSIX-required 0
3582 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3583 new Fiji rules. This is a more-compact way to represent
3584 far-future timestamps for America/Godthab, America/Santiago,
3585 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3586 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3587 this change. (Derived from a suggestion by Arthur David Olson.)
3589 Allow POSIX-like TZ strings where daylight saving time is in
3590 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3591 Argentina Summer Time all year. This supports a more-compact way
3592 to represent the 2013d data for America/Argentina/San_Luis.
3593 Because of the change for San Luis noted above this change does not
3594 affect the current data. (Thanks to Andrew Main (Zefram) for
3595 suggestions that improved this change.)
3597 Where these two TZ changes take effect, there is a minor extension
3598 to the tz file format in that it allows new values for the
3599 embedded TZ-format string, and the tz file format version number
3600 has therefore been increased from 2 to 3 as a precaution.
3601 Version-2-based client code should continue to work as before for
3602 all timestamps before 2038. Existing version-2-based client code
3603 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3604 files, and typically works in practice even for timestamps after
3605 2037; the only known exception is America/Godthab.
3607 Changes affecting timestamps before 1970
3609 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3610 some errors before 1947.
3612 Some zones have been turned into links, when they differ from existing
3613 zones only in older data entries that were likely invented or that
3614 differ only in LMT or transitions from LMT. These changes affect
3615 only timestamps before 1943. The affected zones are:
3616 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3617 America/Grenada, America/Guadeloupe, America/Marigot,
3618 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3619 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3620 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3621 confirming that the old Europe/Vaduz zone was wrong and the new
3622 link is better for WWII-era times.)
3624 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3625 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3628 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3629 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3632 Change the date of the circa-1850 Zurich transition from 1849-09-12
3633 to 1853-07-16, overriding Shanks with data from Messerli about
3634 postal and telegraph time in Switzerland.
3636 Changes affecting time zone abbreviations before 1970
3638 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3639 as Jakarta was called Batavia back then.
3641 Changes affecting API
3643 The 'zic' command now outputs a dummy transition when far-future
3644 data can't be summarized using a TZ string, and uses a 402-year
3645 window rather than a 400-year window. For the current data, this
3646 affects only the Asia/Tehran file. It does not affect any of the
3647 timestamps that this file represents, so zdump outputs the same
3648 information as before. (Thanks to Andrew Main (Zefram).)
3650 The 'date' command has a new '-r' option, which lets you specify
3651 the integer time to display, a la FreeBSD.
3653 The 'tzselect' command has two new options '-c' and '-n', which lets you
3654 select a zone based on latitude and longitude.
3656 The 'zic' command's '-v' option now warns about constructs that
3657 require the new version-3 binary file format. (Thanks to Arthur
3658 David Olson for the suggestion.)
3660 Support for floating-point time_t has been removed.
3661 It was always dicey, and POSIX no longer requires it.
3662 (Thanks to Eric Blake for suggesting to the POSIX committee to
3663 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3664 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3665 bugs and elucidating some of the corners of the old floating-point
3668 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3669 changed back to the old practice of using 'long' to represent UT
3670 offsets. This had been inadvertently and mistakenly changed to
3671 'int_fast32_t'. (Thanks to Christos Zoulas.)
3673 The code avoids undefined behavior on integer overflow in some
3674 more places, including gmtime, localtime, mktime and zdump.
3676 Changes affecting the zdump utility
3678 zdump now outputs "UT" when referring to Universal Time, not "UTC".
3679 "UTC" does not make sense for timestamps that predate the introduction
3680 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
3681 for clarifying UT vs UTC.)
3683 Data changes affecting behavior of tzselect and similar programs
3685 Country code BQ is now called the more-common name "Caribbean Netherlands"
3686 rather than the more-official "Bonaire, St Eustatius & Saba".
3688 Remove from zone.tab the names America/Montreal, America/Shiprock,
3689 and Antarctica/South_Pole, as they are equivalent to existing
3690 same-country-code zones for post-1970 timestamps. The data entries for
3691 these names are unchanged, so the names continue to work as before.
3693 Changes affecting code internals
3695 zic -c now runs way faster on 64-bit hosts when given large numbers.
3697 zic now uses vfprintf to avoid allocating and freeing some memory.
3699 tzselect now computes the list of continents from the data,
3700 rather than have it hard-coded.
3702 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3704 Changes affecting the build procedure
3706 The 'leapseconds' file is now generated automatically from a
3707 new file 'leap-seconds.list', which is a copy of
3708 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3709 A new source file 'leapseconds.awk' implements this.
3710 The goal is simplification of the future maintenance of 'leapseconds'.
3712 When building the 'posix' or 'right' subdirectories, if the
3713 subdirectory would be a copy of the default subdirectory, it is
3714 now made a symbolic link if that is supported. This saves about
3715 2 MB of file system space.
3717 The links America/Shiprock and Antarctica/South_Pole have been
3718 moved to the 'backward' file. This affects only nondefault builds
3719 that omit 'backward'.
3721 Changes affecting version-control only
3723 .gitignore now ignores 'date'.
3725 Changes affecting documentation and commentary
3727 Changes to the 'tzfile' man page
3729 It now mentions that the binary file format may be extended in
3730 future versions by appending data.
3732 It now refers to the 'zdump' and 'zic' man pages.
3734 Changes to the 'zic' man page
3736 It lists conditions that elicit a warning with '-v'.
3738 It says that the behavior is unspecified when duplicate names
3739 are given, or if the source of one link is the target of another.
3741 Its examples are updated to match the latest data.
3743 The definition of white space has been clarified slightly.
3744 (Thanks to Michael Deckers.)
3746 Changes to the 'Theory' file
3748 There is a new section about the accuracy of the tz database,
3749 describing the many ways that errors can creep in, and
3750 explaining why so many of the pre-1970 timestamps are wrong or
3751 misleading (thanks to Steve Allen, Lester Caine, and Garrett
3752 Wollman for discussions that contributed to this).
3754 The 'Theory' file describes LMT better (this follows a
3755 suggestion by Guy Harris).
3757 It refers to the 2013 edition of POSIX rather than the 2004 edition.
3759 It's mentioned that excluding 'backward' should not affect the
3760 other data, and it suggests at least one zone.tab name per
3761 inhabited country (thanks to Stephen Colebourne).
3763 Some longstanding restrictions on names are documented, e.g.,
3764 'America/New_York' precludes 'America/New_York/Bronx'.
3766 It gives more reasons for the 1970 cutoff.
3768 It now mentions which time_t variants are supported, such as
3769 signed integer time_t. (Thanks to Paul Goyette for reporting
3770 typos in an experimental version of this change.)
3772 (Thanks to Philip Newton for correcting typos in these changes.)
3774 Documentation and commentary is more careful to distinguish UT in
3775 general from UTC in particular. (Thanks to Steve Allen.)
3777 Add a better source for the Zurich 1894 transition.
3778 (Thanks to Pierre-Yves Berger.)
3780 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
3783 Release 2013d - 2013-07-05 07:38:01 -0700
3785 Changes affecting future timestamps:
3787 Morocco's midsummer transitions this year are July 7 and August 10,
3788 not July 9 and August 8. (Thanks to Andrew Paprocki.)
3790 Israel now falls back on the last Sunday of October.
3791 (Thanks to Ephraim Silverberg.)
3793 Changes affecting past timestamps:
3795 Specify Jerusalem's location more precisely; this changes the pre-1880
3798 Changing affecting metadata only:
3800 Fix typos in the entries for country codes BQ and SX.
3802 Changes affecting code:
3804 Rework the code to fix a bug with handling Australia/Macquarie on
3805 32-bit hosts (thanks to Arthur David Olson).
3807 Port to platforms like NetBSD, where time_t can be wider than long.
3809 Add support for testing time_t types other than the system's.
3810 Run 'make check_time_t_alternatives' to try this out.
3811 Currently, the tests fail for unsigned time_t;
3812 this should get fixed at some point.
3814 Changes affecting documentation and commentary:
3816 Deemphasize the significance of national borders.
3818 Update the zdump man page.
3820 Remove obsolete NOID comment (thanks to Denis Excoffier).
3822 Update several URLs and comments in the web pages.
3824 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3826 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3829 Release 2013c - 2013-04-19 16:17:40 -0700
3831 Changes affecting current and future timestamps:
3833 Palestine observed DST starting March 29, 2013. (Thanks to
3834 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
3835 with the predicted rules being the last Thursday in March at 24:00
3836 to the first Friday on or after September 21 at 01:00.
3838 Assume that the recent change to Paraguay's DST rules is permanent,
3839 by moving the end of DST to the 4th Sunday in March every year.
3840 (Thanks to Carlos Raúl Perasso.)
3842 Changes affecting past timestamps:
3844 Fix some historical data for Palestine to agree with that of
3845 timeanddate.com, as follows:
3847 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3850 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3853 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3855 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
3857 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
3859 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
3861 Fix times of habitation for Macquarie to agree with the Tasmania
3862 Parks & Wildlife Service history, which indicates that permanent
3863 habitation was 1899-1919 and 1948 on.
3865 Changing affecting metadata only:
3867 Macquarie Island is politically part of Australia, not Antarctica.
3868 (Thanks to Tobias Conradi.)
3870 Sort Macquarie more-consistently with other parts of Australia.
3871 (Thanks to Tim Parenti.)
3874 Release 2013b - 2013-03-10 22:33:40 -0700
3876 Changes affecting current and future timestamps:
3878 Haiti uses US daylight-saving rules this year, and presumably future years.
3879 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
3881 Paraguay will end DST on March 24 this year.
3882 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
3884 Morocco does not observe DST during Ramadan;
3885 try to predict Ramadan in Morocco as best we can.
3886 (Thanks to Erik Homoet for the heads-up.)
3888 Changes affecting commentary:
3890 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
3891 Update URL for Solaris. Mention Internet RFC 6557.
3892 Update Internet RFCs 2445->5545, 2822->5322.
3893 Switch from FTP to HTTP for Internet RFCs.
3896 Release 2013a - 2013-02-27 09:20:35 -0800
3898 Change affecting binary data format:
3900 The zone offset at the end of version-2-format zone files is now
3901 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
3903 Changes affecting current and future timestamps:
3905 Chile's 2013 rules, and we guess rules for 2014 and later, will be
3906 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
3907 (Thanks to Steffen Thorsen and Robert Elz.)
3909 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
3910 (Thanks to Tobias Conradi and Arthur David Olson.)
3912 Many changes affect historical timestamps before 1940.
3913 These were deduced from: Milne J. Civil time. Geogr J. 1899
3914 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
3916 Changes affecting the code:
3918 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
3919 the data). (Thanks to Arthur David Olson.)
3921 Fix localtime bug when time_t is unsigned and data files were generated
3922 by a signed time_t system. (Thanks to Doug Bailey for reporting and
3923 to Arthur David Olson for fixing.)
3925 Allow the email address for bug reports to be set by the packager.
3926 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
3928 Update HTML checking to be compatible with Ubuntu 12.10.
3930 Check that files are a safe subset of ASCII. At some point we may
3931 relax this requirement to a safe subset of UTF-8. Without the
3932 check, some non-UTF-8 encodings were leaking into the distribution.
3936 Restore a comment about copyright notices that was inadvertently deleted.
3937 (Thanks to Arthur David Olson.)
3939 Improve the commentary about which districts observe what times
3940 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
3942 Add web page links to tz.js.
3944 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
3947 Release 2012j - 2012-11-12 18:34:49 -0800
3949 Libya moved to CET this weekend, but with DST planned next year.
3950 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
3952 Signatures now have the extension .asc, not .sign, as that's more
3953 standard. (Thanks to Phil Pennock.)
3955 The output of 'zdump --version', and of 'zic --version', now
3956 uses a format that is more typical for --version.
3957 (Thanks to Joseph S. Myers.)
3959 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
3960 now uses tz@iana.org rather than the old elsie address.
3962 zic -v now complains about abbreviations that are less than 3
3963 or more than 6 characters, as per Posix. Formerly, it checked
3964 for abbreviations that were more than 3.
3966 'make public' no longer puts its temporary directory under /tmp,
3967 and uses the just-built zic rather than the system zic.
3969 Various fixes to documentation and commentary.
3972 Release 2012i - 2012-11-03 12:57:09 -0700
3974 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
3976 Linker flags can now be specified via LDFLAGS.
3977 AWK now defaults to 'awk', not 'nawk'.
3978 The shell in tzselect now defaults to /bin/bash, but this can
3979 be overridden by specifying KSHELL.
3980 The main web page now mentions the unofficial GitHub repository.
3981 (Thanks to Mike Frysinger.)
3983 Tarball signatures can now be built by running 'make signatures'.
3984 There are also new makefile rules 'tarballs', 'check_public', and
3985 separate makefile rules for each tarball and signature file.
3986 A few makefile rules are now more portable to strict POSIX.
3988 The main web page now lists the canonical IANA URL.
3991 Release 2012h - 2012-10-26 22:49:10 -0700
3993 Bahia no longer has DST. (Thanks to Kelley Cook.)
3995 Tocantins has DST. (Thanks to Rodrigo Severo.)
3997 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
3999 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
4003 More C modernization, except that at Arthur David Olson's suggestion
4004 the instances of 'register' were kept.
4007 Release 2012g - 2012-10-17 20:59:45 -0700
4009 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
4011 Palestine fall 2012. (Thanks to Steffen Thorsen.)
4015 To attack the version-number problem, this release ships the file
4016 'Makefile' (which contains the release number) in both the tzcode and
4017 the tzdata tarballs. The two Makefiles are identical, and should be
4018 identical in any matching pair of tarballs, so it shouldn't matter
4019 which order you extract the tarballs. Perhaps we can come up with a
4020 better version-number scheme at some point; this scheme does have the
4021 virtue of not adding more files.
4024 Release 2012f - 2012-09-12 23:17:03 -0700
4026 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4027 20 this year. (Thanks to Steffen Thorsen.)
4030 Release 2012e - 2012-08-02 20:44:55 -0700
4032 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4033 (Thanks to Steffen Thorsen.)
4035 * Use a single version number for both code and data.
4037 * .gitignore: New file.
4039 * Remove trailing white space.
4042 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4044 Changes for Morocco's timestamps, which take effect in a couple of
4045 hours, along with infrastructure changes to accommodate how the tz
4046 code and data are released on IANA.
4049 Release data2012c - 2012-03-27 12:17:25 -0400
4052 Summer time changes for Morocco (to start late April 2012)
4055 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4058 Haiti following US/Canada rules for 2012 (and we're assuming,
4059 for now anyway, for the future).
4062 Release 2012b - 2012-03-02 12:29:15 +0700
4064 There is just one change to tzcode2012b (compared with 2012a):
4065 the Makefile that was accidentally included with 2012a has been
4066 replaced with the version that should have been there, which is
4067 identical with the previous version (from tzcode2011i).
4069 There are just two changes in tzdata2012b compared with 2012a.
4071 Most significantly, summer time in Cuba has been delayed 3 weeks
4072 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4073 date, as listed in 2012a) is just a little over a week away, this
4076 Less importantly, an excess tab in one of the changes in zone.tab
4077 in 2012a has been removed.
4080 Release 2012a - 2012-03-01 18:28:10 +0700
4082 The changes in tzcode2012a (compared to the previous version, 2011i)
4083 are entirely to the README and tz-art.htm and tz-link.htm files, if
4084 none of those concern you, you can ignore the code update. The changes
4085 reflect the changed addresses for the mailing list and the code and
4086 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4087 has been added to tz-link.htm).
4089 In tzdata2012a (compared to the previous release, which was 2011n)
4090 the major changes are:
4091 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4092 Falkland Islands onto permanent summer time (we're assuming for the
4093 foreseeable future, though 2012 is all we're fairly certain of.)
4094 Armenia has abolished Summer Time.
4095 Tokelau jumped the International Date Line back last December
4096 (just the same as their near neighbour, Samoa).
4097 America/Creston is a new zone for a small area of British Columbia
4098 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4100 Other minor changes are:
4101 Corrections to 1918 Canadian summer time end dates.
4102 Updated URL for UK time zone history (in comments)
4103 A few typos in Le Corre's list of free French place names (comments)
4106 Release data2011n - 2011-10-30 14:57:54 +0700
4108 There are three changes of note - most urgently, Cuba (America/Havana)
4109 has extended summer time by two weeks, now to end on Nov 13, rather than
4110 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4111 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4112 all, and consequently that zone has been removed (again) and reinstated
4113 in the "backward" file as a link to Europe/Chisinau. And third, the
4114 end date for Fiji's summer time this summer was moved forward from the
4115 earlier planned Feb 26, to Jan 22.
4117 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4118 (and the incorrect syntax that was in the 2011m version of that file
4119 is so fixed - it would have been fixed in a different way had this
4120 change not happened - that's the "missing" sccs version id).
4123 Release data2011m - 2011-10-24 21:42:16 +0700
4125 In particular, the typos in comments in the data (2011-11-17 should have
4126 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4127 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4128 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
4129 Tim Parenti, and also Denys Gavrysh)
4131 In addition, I added Europe/Tiraspol to zone.tab.
4133 This time, all the files have new version numbers... (including the files
4134 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4135 version numbers there...)
4138 Release data2011l - 2011-10-10 11:15:43 +0700
4140 There are just 2 changes that cause different generated tzdata files from
4141 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4142 is included, but commented out. Compared with the diff I sent out last week,
4143 this version also includes attributions for the sources for the changes
4144 (in much the same format as ado used, but the html tags have not been
4145 checked, verified, or used in any way at all, so if there are errors there,
4146 please let me know.)
4149 Release data2011k - 2011-09-20 17:54:03 -0400
4154 Release data2011j - 2011-09-12 09:22:49 -0400
4156 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4157 Tanzania); there are also two spelling corrections to comments in
4158 the australasia file (with thanks to Christos Zoulas).
4161 Release 2011i - 2011-08-29 05:56:32 -0400
4166 Release data2011h - 2011-06-15 18:41:48 -0400
4168 Russia and Curaçao changes
4171 Release 2011g - 2011-04-25 09:07:22 -0400
4173 update the rules for Egypt to reflect its abandonment of DST this year
4176 Release 2011f - 2011-04-06 17:14:53 -0400
4181 Release 2011e - 2011-03-31 16:04:38 -0400
4183 Morocco, Chile, and tz-link changes
4186 Release 2011d - 2011-03-14 09:18:01 -0400
4188 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4191 Release 2011c - 2011-03-07 09:30:09 -0500
4193 These do affect current timestamps in Chile and Annette Island, Canada.
4196 Release 2011b - 2011-02-07 08:44:50 -0500
4201 Release 2011a - 2011-01-24 10:30:16 -0500
4206 Release data2010o - 2010-11-01 09:18:23 -0400
4208 change to the end of DST in Fiji in 2011
4211 Release 2010n - 2010-10-25 08:19:17 -0400
4216 Release 2010m - 2010-09-27 09:24:48 -0400
4218 Hong Kong, Vostok, and zic.c changes
4221 Release 2010l - 2010-08-16 06:57:25 -0400
4226 Release 2010k - 2010-07-26 10:42:27 -0400
4231 Release 2010j - 2010-05-10 09:07:48 -0400
4233 changes for Bahía de Banderas and for version naming
4236 Release data2010i - 2010-04-16 18:50:45 -0400
4238 the end of DST in Morocco on 2010-08-08
4241 Release data2010h - 2010-04-05 09:58:56 -0400
4246 Release data2010g - 2010-03-24 11:14:53 -0400
4251 Release 2010f - 2010-03-22 09:45:46 -0400
4256 Release data2010e - 2010-03-08 14:24:27 -0500
4258 corrects the Dhaka bug found by Danvin Ruangchan
4261 Release data2010d - 2010-03-06 07:26:01 -0500
4266 Release 2010c - 2010-03-01 09:20:58 -0500
4268 changes including KRE's suggestion for earlier initialization of
4269 "goahead" and "goback" structure elements
4272 Release code2010a - 2010-02-16 10:40:04 -0500
4277 Release data2010b - 2010-01-20 12:37:01 -0500
4282 Release data2010a - 2010-01-18 08:30:04 -0500
4287 Release data2009u - 2009-12-26 08:32:28 -0500
4289 changes to DST in Bangladesh
4292 Release 2009t - 2009-12-21 13:24:27 -0500
4297 Release data2009s - 2009-11-14 10:26:32 -0500
4299 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4302 Release 2009r - 2009-11-09 10:10:31 -0500
4304 "antarctica" and "tz-link.htm" changes
4307 Release 2009q - 2009-11-02 09:12:40 -0500
4309 with two corrections as reported by Eric Muller and Philip Newton
4312 Release data2009p - 2009-10-23 15:05:27 -0400
4314 Argentina (including San Luis) changes (with the correction from
4318 Release data2009o - 2009-10-14 16:49:38 -0400
4320 Samoa (commentary only), Pakistan, and Bangladesh changes
4323 Release data2009n - 2009-09-22 15:13:38 -0400
4325 added commentary for Argentina and a change to the end of DST in
4329 Release data2009m - 2009-09-03 10:23:43 -0400
4331 Samoa and Palestine changes
4334 Release data2009l - 2009-08-14 09:13:07 -0400
4336 Samoa (comments only) and Egypt
4339 Release 2009k - 2009-07-20 09:46:08 -0400
4344 Release data2009j - 2009-06-15 06:43:59 -0400
4346 Bangladesh change (with a short turnaround since the DST change is
4350 Release 2009i - 2009-06-08 09:21:22 -0400
4352 updating for DST in Bangladesh this year
4355 Release 2009h - 2009-05-26 09:19:14 -0400
4360 Release data2009g - 2009-04-20 16:34:07 -0400
4365 Release data2009f - 2009-04-10 11:00:52 -0400
4367 correct DST in Pakistan
4370 Release 2009e - 2009-04-06 09:08:11 -0400
4375 Release 2009d - 2009-03-23 09:38:12 -0400
4377 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4380 Release data2009c - 2009-03-16 09:47:51 -0400
4382 change to the start of Cuban DST
4385 Release 2009b - 2009-02-09 11:15:22 -0500
4390 Release 2009a - 2009-01-21 10:09:39 -0500
4395 Release data2008i - 2008-10-21 12:10:25 -0400
4397 southamerica and zone.tab files, with Argentina DST rule changes and
4398 United States zone reordering and recommenting
4401 Release 2008h - 2008-10-13 07:33:56 -0400
4406 Release 2008g - 2008-10-06 09:03:18 -0400
4408 Fix a broken HTML anchor and update Brazil's DST transitions;
4409 there's also a slight reordering of information in tz-art.htm.
4412 Release data2008f - 2008-09-09 22:33:26 -0400
4417 Release 2008e - 2008-07-28 14:11:17 -0400
4419 changes by Arthur David Olson and Jesper Nørgaard Welen
4422 Release data2008d - 2008-07-07 09:51:38 -0400
4424 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4427 Release data2008c - 2008-05-19 17:48:03 -0400
4429 Pakistan, Morocco, and Mongolia
4432 Release data2008b - 2008-03-24 08:30:59 -0400
4434 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4438 Release 2008a - 2008-03-08 05:42:16 -0500
4443 Release 2007k - 2007-12-31 10:25:22 -0500
4445 most importantly, changes to the "southamerica" file based on
4446 Argentina's readoption of daylight saving time
4449 Release 2007j - 2007-12-03 09:51:01 -0500
4451 1. eliminate the "P" (parameter) macro;
4453 2. the "noncontroversial" changes circulated on the time zone
4454 mailing list (less the changes to "logwtmp.c");
4456 3. eliminate "too many transition" errors when "min" is used in time
4459 4. changes by Paul Eggert (including updated information for Venezuela).
4462 Release data2007i - 2007-10-30 10:28:11 -0400
4464 changes for Cuba and Syria
4467 Release 2007h - 2007-10-01 10:05:51 -0400
4469 changes by Paul Eggert, as well as an updated link to the ICU
4470 project in tz-link.htm
4473 Release 2007g - 2007-08-20 10:47:59 -0400
4475 changes by Paul Eggert
4477 The "leapseconds" file has been updated to incorporate the most
4478 recent International Earth Rotation and Reference Systems Service
4481 There's an addition to tz-art.htm regarding the television show "Medium".
4484 Release 2007f - 2007-05-07 10:46:46 -0400
4486 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4489 changes to zic.c to allow hour values greater than 24 (along with
4490 Paul's improved time value overflow checking)
4493 Release 2007e - 2007-04-02 10:11:52 -0400
4495 Syria and Honduras changes by Paul Eggert
4497 zic.c variable renaming changes by Arthur David Olson
4500 Release 2007d - 2007-03-20 08:48:30 -0400
4502 changes by Paul Eggert
4504 the elimination of white space at the ends of lines
4507 Release 2007c - 2007-02-26 09:09:37 -0500
4509 changes by Paul Eggert
4512 Release 2007b - 2007-02-12 09:34:20 -0500
4514 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4516 changes to the commentary in "leapseconds" reflecting the IERS
4517 announcement that there is to be no positive leap second at the end
4521 Release 2007a - 2007-01-08 12:28:29 -0500
4523 changes by Paul Eggert
4525 Derick Rethans's Asmara change
4527 Oscar van Vlijmen's Easter Island local mean time change
4529 symbolic link changes
4532 Release 2006p - 2006-11-27 08:54:27 -0500
4534 changes by Paul Eggert
4537 Release 2006o - 2006-11-06 09:18:07 -0500
4539 changes by Paul Eggert
4542 Release 2006n - 2006-10-10 11:32:06 -0400
4544 changes by Paul Eggert
4547 Release 2006m - 2006-10-02 15:32:35 -0400
4549 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4551 (minimalist) changes to zic.8 to clarify "until" information
4554 Release data2006l - 2006-09-18 12:58:11 -0400
4556 Paul's best-effort work on this coming weekend's Egypt time change
4559 Release 2006k - 2006-08-28 12:19:09 -0400
4561 changes by Paul Eggert
4564 Release 2006j - 2006-08-21 09:56:32 -0400
4566 changes by Paul Eggert
4569 Release code2006i - 2006-08-07 12:30:55 -0400
4573 Ken Pizzini's conversion script
4576 Release code2006h - 2006-07-24 09:19:37 -0400
4578 adds public domain notices to four files
4580 includes a fix for transition times being off by a second
4582 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4585 Release 2006g - 2006-05-08 17:18:09 -0400
4587 northamerica changes by Paul Eggert
4590 Release 2006f - 2006-05-01 11:46:00 -0400
4592 a missing version number problem is fixed (with thanks to Bradley
4593 White for catching the problem)
4596 Release 2006d - 2006-04-17 14:33:43 -0400
4598 changes by Paul Eggert
4600 added new items to tz-arts.htm that were found by Paul
4603 Release 2006c - 2006-04-03 10:09:32 -0400
4605 two sets of data changes by Paul Eggert
4607 a fencepost error fix in zic.c
4609 changes to zic.c and the "europe" file to minimize differences
4610 between output produced by the old 32-bit zic and the new 64-bit
4614 Release 2006b - 2006-02-20 10:08:18 -0500
4615 [tz32code2006b + tz64code2006b + tzdata2006b]
4619 All SCCS IDs were bumped to "8.1" for this release.
4622 Release 2006a - 2006-01-30 08:59:31 -0500
4624 changes by Paul Eggert (in particular, Indiana time zone moves)
4626 an addition to the zic manual page to describe how special-case
4627 transitions are handled
4630 Release 2005r - 2005-12-27 09:27:13 -0500
4632 Canadian changes by Paul Eggert
4634 They also add "<pre>" directives to time zone data files and reflect
4635 changes to warning message logic in "zdump.c" (but with calls to
4636 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4639 Release 2005q - 2005-12-13 09:17:09 -0500
4641 Nothing earth-shaking here:
4642 1. Electronic mail addresses have been removed.
4643 2. Casts of the return value of exit have been removed.
4644 3. Casts of the argument of is.* macros have been added.
4645 4. Indentation in one section of zic.c has been fixed.
4646 5. References to dead URLs in the data files have been dealt with.
4649 Release 2005p - 2005-12-05 10:30:53 -0500
4651 "systemv", "tz-link.htm", and "zdump.c" changes
4652 (less the casts of arguments to the is* macros)
4655 Release 2005o - 2005-11-28 10:55:26 -0500
4657 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4659 zdump.c lint fixes by Arthur David Olson
4662 Release 2005n - 2005-10-03 09:44:09 -0400
4664 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4668 Release 2005m - 2005-08-29 12:15:40 -0400
4670 changes by Paul Eggert (with a small tweak to the tz-art change)
4672 a declaration of an unused variable has been removed from zdump.c
4675 Release 2005l - 2005-08-22 12:06:39 -0400
4677 changes by Paul Eggert
4679 overflow/underflow checks by Arthur David Olson, minus changes to
4680 the "Theory" file about the pending addition of 64-bit data (I grow
4681 less confident of the changes being accepted with each passing day,
4682 and the changes no longer increase the data files nine-fold--there's
4683 less than a doubling in size by my local Sun's reckoning)
4686 Release 2005k - 2005-07-14 14:14:24 -0400
4688 The "leapseconds" file has been edited to reflect the recently
4689 announced leap second at the end of 2005.
4691 I've also deleted electronic mail addresses from the files as an
4695 Release 2005j - 2005-06-13 14:34:13 -0400
4697 These reflect changes to limit the length of time zone abbreviations
4698 and the characters used in those abbreviations.
4700 There are also changes to handle POSIX-style "quoted" timezone
4701 environment variables.
4703 The changes were circulated on the time zone mailing list; the only
4704 change since then was the removal of a couple of minimum-length of
4705 abbreviation checks.
4708 Release data2005i - 2005-04-21 15:04:16 -0400
4710 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4713 Release 2005h - 2005-04-04 11:24:47 -0400
4715 changes by Paul Eggert
4717 minor changes to Makefile and zdump.c to produce more useful output
4718 when doing a "make typecheck"
4721 Release 2005g - 2005-03-14 10:11:21 -0500
4723 changes by Paul Eggert (a change to current DST rules in Uruguay and
4724 an update to a link to time zone software)
4727 Release 2005f - 2005-03-01 08:45:32 -0500
4729 data and documentation changes by Paul Eggert
4732 Release 2005e - 2005-02-10 15:59:44 -0500
4737 Release code2005d - 2005-01-31 09:21:47 -0500
4739 make zic complain about links to links if the -v flag is used
4741 have "make public" do more code checking
4743 add an include to "localtime.c" for the benefit of gcc systems
4746 Release 2005c - 2005-01-17 18:36:29 -0500
4748 get better results when mktime runs on a system where time_t is double
4750 changes to the data files (most importantly to Paraguay)
4753 Release 2005b - 2005-01-10 09:19:54 -0500
4755 Get localtime and gmtime working on systems with exotic time_t types.
4757 Update the leap second commentary in the "leapseconds" file.
4760 Release 2005a - 2005-01-01 13:13:44 -0500
4765 Release code2004i - 2004-12-14 13:42:58 -0500
4767 Deal with systems where time_t is unsigned.
4770 Release code2004h - 2004-12-07 11:40:18 -0500
4772 64-bit-time_t changes
4775 Release 2004g - 2004-11-02 09:06:01 -0500
4777 update to Cuba (taking effect this weekend)
4779 other changes by Paul Eggert
4781 correction of the spelling of Oslo
4783 changed versions of difftime.c and private.h
4786 Release code2004f - 2004-10-21 10:25:22 -0400
4788 Cope with wide-ranging tm_year values.
4791 Release 2004e - 2004-10-11 14:47:21 -0400
4793 Brazil/Argentina/Israel changes by Paul Eggert
4795 changes to tz-link.htm by Paul
4797 one small fix to Makefile
4800 Release 2004d - 2004-09-22 08:27:29 -0400
4802 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4805 Release 2004c - 2004-08-11 12:06:26 -0400
4807 asctime-related changes
4809 (variants of) some of the documentation changes suggested by Paul Eggert
4812 Release 2004b - 2004-07-19 14:33:35 -0400
4814 data changes by Paul Eggert - most importantly, updates for Argentina
4817 Release 2004a - 2004-05-27 12:00:47 -0400
4819 changes by Paul Eggert
4821 Handle DST transitions that occur at the end of a month in some
4822 years but at the start of the following month in other years.
4824 Add a copy of the correspondence that's the basis for claims about
4825 DST in the Navajo Nation.
4828 Release 2003e - 2003-12-15 09:36:47 -0500
4830 changes by Arthur David Olson (primarily code changes)
4832 changes by Paul Eggert (primarily data changes)
4834 minor changes to "Makefile" and "northamerica" (in the latter case,
4835 optimization of the "Toronto" rules)
4838 Release 2003d - 2003-10-06 09:34:44 -0400
4840 changes by Paul Eggert
4843 Release 2003c - 2003-09-16 10:47:05 -0400
4845 Fix bad returns in zic.c's inleap function.
4846 Thanks to Bradley White for catching the problem!
4849 Release 2003b - 2003-09-16 07:13:44 -0400
4851 Add a "--version" option (and documentation) to the zic and zdump commands.
4853 changes to overflow/underflow checking in zic
4855 a localtime typo fix.
4857 Update the leapseconds and tz-art.htm files.
4860 Release 2003a - 2003-03-24 09:30:54 -0500
4862 changes by Paul Eggert
4864 a few additions and modifications to the tz-art.htm file
4867 Release 2002d - 2002-10-15 13:12:42 -0400
4869 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
4871 There's also a new time zone quote in "tz-art.htm".
4874 Release 2002c - 2002-04-04 11:55:20 -0500
4876 changes by Paul Eggert
4878 Change zic.c to avoid creating symlinks to files that don't exist.
4881 Release 2002b - 2002-01-28 12:56:03 -0500
4883 [These change notes are for Release 2002a, which was corrupted.
4884 2002b was a corrected version of 2002a.]
4886 changes by Paul Eggert
4888 Update the "leapseconds" file to note that there'll be no leap
4889 second at the end of June, 2002.
4891 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
4893 Change to "difftime.c" to avoid sizeof problems.
4896 Release 2001d - 2001-10-09 13:31:32 -0400
4898 changes by Paul Eggert
4901 Release 2001c - 2001-06-05 13:59:55 -0400
4903 changes by Paul Eggert and Andrew Brown
4906 Release 2001b - 2001-04-05 16:44:38 -0400
4908 changes by Paul Eggert (modulo jnorgard's typo fix)
4910 tz-art.htm has been HTMLified.
4913 Release 2001a - 2001-03-13 12:57:44 -0500
4915 changes by Paul Eggert
4917 An addition to the "leapseconds" file: comments with the text of the
4918 latest IERS leap second notice.
4920 Trailing white space has been removed from data file lines, and
4921 repeated spaces in "Rule Jordan" lines in the "asia" file have been
4925 Release 2000h - 2000-12-14 15:33:38 -0500
4927 changes by Paul Eggert
4929 one typo fix in the "art" file
4931 With providence, this is the last update of the millennium.
4934 Release 2000g - 2000-10-10 11:35:22 -0400
4936 changes by Paul Eggert
4938 correction of John Mackin's name submitted by Robert Elz
4940 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
4941 Emmy Awards broadcast.
4944 Release 2000f - 2000-08-10 09:31:58 -0400
4946 changes by Paul Eggert
4948 Added information in "tz-art.htm" on a Seinfeld reference to DST.
4950 Error checking and messages in the "yearistype" script have been
4954 Release 2000e - 2000-07-31 09:27:54 -0400
4956 data changes by Paul Eggert
4958 a change to the default value of the defined constant HAVE_STRERROR
4960 the addition of a Dave Barry quote on DST to the tz-arts file
4963 Release 2000d - 2000-04-20 15:43:04 -0400
4965 changes to the documentation and code of strftime for C99 conformance
4967 a bug fix for date.c
4969 These are based on (though modified from) changes by Paul Eggert.
4972 Release 2000c - 2000-03-04 10:31:43 -0500
4974 changes by Paul Eggert
4977 Release 2000b - 2000-02-21 12:16:29 -0500
4979 changes by Paul Eggert and Joseph Myers
4981 modest tweaks to the tz-art.htm and tz-link.htm files
4984 Release 2000a - 2000-01-18 09:21:26 -0500
4986 changes by Paul Eggert
4988 The two hypertext documents have also been renamed.
4991 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
4993 Paul Eggert's changes
4995 additions to the "zic" manual page and the "Arts.htm" file
4998 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
5003 Release data1999h - 1999-10-07 03:50:29 -0400
5005 changes by Paul Eggert to "europe" (most importantly, fixing
5006 Lithuania and Estonia)
5009 Release 1999g - 1999-09-28 11:06:18 -0400
5011 data changes by Paul Eggert (most importantly, the change for
5012 Lebanon that buys correctness for this coming Sunday)
5014 The "code" file contains changes to "Makefile" and "checktab.awk" to
5015 allow better checking of time zone files before they are published.
5018 Release 1999f - 1999-09-23 09:48:14 -0400
5020 changes by Arthur David Olson and Paul Eggert
5023 Release 1999e - 1999-08-17 15:20:54 -0400
5025 changes circulated by Paul Eggert, although the change to handling
5026 of DST-specifying timezone names has been commented out for now
5027 (search for "XXX" in "localtime.c" for details). These files also
5028 do not make any changes to the start of DST in Brazil.
5030 In addition to Paul's changes, there are updates to "Arts.htm" and
5034 Release 1999d - 1999-03-30 11:31:07 -0500
5036 changes by Paul Eggert
5038 The Makefile's "make public" rule has also been changed to do a test
5039 compile of each individual time zone data file (which should help
5040 avoid problems such as the one we had with Nicosia).
5043 Release 1999c - 1999-03-25 09:47:47 -0500
5045 changes by Paul Eggert, most importantly the change for Chile.
5048 Release 1999b - 1999-02-01 17:51:44 -0500
5050 changes by Paul Eggert
5052 code changes (suggested by Mani Varadarajan, mani at be.com) for
5053 correct handling of symbolic links when building using a relative directory
5055 code changes to generate correct messages for failed links
5057 updates to the URLs in Arts.htm
5060 Release 1999a - 1999-01-19 16:20:29 -0500
5062 error message internationalizations and corrections in zic.c and
5063 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5067 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5069 changes for Brazil, Chile, and Germany
5071 support for use of "24:00" in the input files for the time zone compiler
5074 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5076 changes by Paul Eggert
5078 correction to a define in the "private.h" file
5081 Release data1998g - 1998-08-11 03:28:35 -0000
5082 [tzdata1998g.tar.gz is missing!]
5084 Lithuanian change provided by mgedmin at pub.osf.it
5086 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5087 "backward") to ensure that the GMT file is created even where folks
5088 don't want the "backward" links (as suggested by Paul Eggert).
5091 Release data1998f - 1998-07-20 13:50:00 -0000
5092 [tzdata1998f.tar.gz is missing!]
5094 Update the "leapseconds" file to include the newly-announced
5095 insertion at the end of 1998.
5098 Release code1998f - 1998-06-01 10:18:31 -0400
5100 addition to localtime.c by Guy Harris
5103 Release 1998e - 1998-05-28 09:56:26 -0400
5105 The Makefile is changed to produce zoneinfo-posix rather than
5106 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5109 data changes by Paul Eggert
5111 changes from Guy Harris to provide asctime_r and ctime_r
5113 A usno1998 file (substantially identical to usno1997) has been added.
5116 Release 1998d - 1998-05-14 11:58:34 -0400
5118 changes to comments (in particular, elimination of references to CIA maps).
5119 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5120 where changes occur.
5123 Release 1998c - 1998-02-28 12:32:26 -0500
5125 changes by Paul Eggert (save the "French correction," on which I'll
5126 wait for the dust to settle)
5130 changes and additions to Arts.htm
5133 Release 1998b - 1998-01-17 14:31:51 -0500
5135 URL cleanups and additions
5138 Release 1998a - 1998-01-13 12:37:35 -0500
5140 changes by Paul Eggert
5143 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5145 changes by Paul Eggert, with minor modifications from Arthur David
5146 Olson to make the files more browser friendly
5149 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5151 minor changes to put "TZif" at the start of each timezone information file
5153 a rule has also been added to the Makefile so you can
5155 to just recompile the zone information files (rather than doing a
5156 full "make install" with its other effects).
5159 Release data1997i - 1997-10-07 08:45:38 -0400
5161 changes to Africa by Paul Eggert
5164 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5166 corrections for Uruguay (and other locations)
5168 Arthur David Olson's simple-minded fix allowing mktime to both
5169 correctly handle leap seconds and correctly handle tm_sec values
5170 upon which arithmetic has been performed.
5173 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5175 Paul Eggert's updates
5177 a small change to a function prototype;
5179 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5180 include information on Around the World in Eighty Days.
5183 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5185 fixes to zic's error handling
5187 changes inspired by the item circulated on Slovenia
5189 The description of Web resources has been HTMLified for browsing
5192 A new piece of tz-related music has been added to the "Music" file.
5195 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5197 Paul Eggert's latest suggestions
5200 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5202 changes to "zic.c" to correct performance of the "-s" option
5204 a new file "usno1997"
5207 Release data1997c - 1997-03-04 09:58:18 -0500
5212 Release 1997b - 1997-02-27 18:34:19 -0500
5214 The data file incorporates the 1997 leap second.
5216 The code file incorporates Arthur David Olson's take on the
5217 zic/multiprocessor/directory-creation situation.
5220 Release 1997a - 1997-01-21 09:11:10 -0500
5222 Paul Eggert's Antarctica (and other changes)
5224 Arthur David Olson finessed the "getopt" issue by checking against
5225 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5226 is returned while SunOS 5.5's manual says EOF is returned).
5229 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5231 Paul Eggert's latest changes
5234 Release code1996n - 1996-12-16 09:42:02 -0500
5236 link snapping fix from Bruce Evans (via Garrett Wollman)
5239 Release data1996m - 1996-11-24 02:37:34 -0000
5240 [tzdata1996m.tar.gz is missing!]
5242 Paul Eggert's batch of changes
5245 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5247 No functional changes here; the files have simply been changed to
5248 make more use of ISO style dates in comments. The names of the above
5249 files now include the year in full.
5252 Release code96l - 1996-09-08 17:12:20 -0400
5254 tzcode96k was missing a couple of pieces.
5257 Release 96k - 1996-09-08 16:06:22 -0400
5259 the latest round of changes from Paul Eggert
5261 the recent Year 2000 material
5264 Release code96j - 1996-07-30 13:18:53 -0400
5266 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5269 Release code96i - 1996-07-27 20:11:35 -0400
5271 Paul's suggested patch for strftime %V week numbers
5274 Release data96i - 1996-07-01 18:13:04 -0400
5276 "northamerica" and "europe" changes by Paul Eggert
5279 Release code96h - 1996-06-05 08:02:21 -0400
5281 fix for handling transitions specified in Universal Time
5283 Some "public domain" notices have also been added.
5286 Release code96g - 1996-05-16 14:00:26 -0400
5288 fix for the simultaneous-DST-and-zone-change challenge
5291 Release data96h - 1996-05-09 17:40:51 -0400
5293 changes by Paul Eggert
5296 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5297 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5299 The changes get us some of the way to fixing the problems noted in Paul
5300 Eggert's letter yesterday (in addition to a few others). The approach
5301 has been to make zic a bit smarter about figuring out what time zone
5302 abbreviations apply just after the time specified in the "UNTIL" part
5303 of a zone line. Putting the smarts in zic means avoiding having
5304 transition times show up in both "Zone" lines and "Rule" lines, which
5305 in turn avoids multiple transition time entries in time zone files.
5306 (This also makes the zic input files such as "europe" a bit shorter and
5307 should ease maintenance.)
5310 Release data96f - 1996-04-19 19:20:03 -0000
5311 [tzdata96f.tar.gz is missing!]
5313 The only changes are to the "northamerica" file; the time zone
5314 abbreviation for Denver is corrected to MST (and MDT), and the
5315 comments for Mexico have been updated.
5318 Release data96e - 1996-03-19 17:37:26 -0500
5320 Proposals by Paul Eggert, in particular the Portugal change that
5321 comes into play at the end of this month.
5324 Release data96d - 1996-03-18 20:49:39 -0500
5329 Release code96e - 1996-02-29 15:43:27 -0000
5330 [tzcode96e.tar.gz is missing!]
5332 internationalization changes and the fix to the documentation for strftime
5335 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5337 The "code" file simply updates Bob Kridle's electronic address.
5339 The "data" file updates rules for Mexico.
5342 Release data96b - 1996-01-27 15:44:42 -0500
5347 Release code96c - 1996-01-16 16:58:15 -0500
5349 leap-year streamlining and binary-search changes
5354 Release code96b - 1996-01-10 20:42:39 -0500
5356 fixes and enhancements from Paul Eggert, including code that
5357 emulates the behavior of recent versions of the SunOS "date"
5361 Release 96a - 1996-01-06 09:08:24 -0500
5365 fixes to strftime.c for correct ISO 8601 week number generation,
5366 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5367 numbers (which are not necessarily the same as calendar year numbers)
5370 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5372 The latest revisions from Paul Eggert are included, the usno1995
5373 file has been updated, and a new file ("WWW") covering useful URLs
5377 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5379 A simplification of a macro definition, a change to data for Sudan,
5380 and (for last minute shoppers) notes in the "Music" file on the CD
5384 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5386 (slightly reformatted) 8-bit-clean proposed patch
5388 minor patch: US/Eastern -> America/New_York
5390 snapshot of the USNO's latest data ("usno1995")
5392 some other minor cleanups
5395 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5396 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5400 support for 64-bit time_t's
5402 optimization in localtime.c
5405 Release code95e - 1995-10-13 13:23:57 -0400
5407 the mktime change to scan from future to past when trying to find time zone
5411 Release data95i - 1995-09-26 10:43:26 -0400
5413 For Canada/Central, guess that the Sun customer's "one week too
5414 early" was just a approximation, and the true error is one month
5415 too early. This is consistent with the rest of Canada.
5418 Release data95h - 1995-09-21 11:26:48 -0400
5420 latest changes from Paul Eggert
5423 Release code95d - 1995-09-14 11:14:45 -0400
5425 the addition of a "Music" file, which documents four recorded
5426 versions of the tune "Save That Time".
5429 Release data95g - 1995-09-01 17:21:36 -0400
5431 "yearistype" correction
5434 Release data95f - 1995-08-28 20:46:56 -0400
5436 Paul Eggert's change to the australasia file
5439 Release data95e - 1995-07-08 18:02:34 -0400
5441 The only change is a leap second at the end of this year.
5442 Thanks to Bradley White for forwarding news on the leap second.
5445 Release data95d - 1995-07-03 13:26:22 -0400
5447 Paul Eggert's changes
5450 Release data95c - 1995-07-02 19:19:28 -0400
5452 changes to "asia", "backward", "europe", and "southamerica"
5453 (read: northamericacentrics need not apply)
5456 Release code95c - 1995-03-13 14:00:46 -0500
5458 one-line fix for sign extension problems in detzcode
5461 Release 95b - 1995-03-04 11:22:38 -0500
5463 Minor changes in both:
5465 The "code" file contains a workaround for the lack of "unistd.h" in
5466 Microsoft C++ version 7.
5468 The "data" file contains a fixed "Link" for America/Shiprock.
5471 Release 94h - 1994-12-10 12:51:14 -0500
5475 * incorporate the changes to "zdump" and "date" to make changes to
5476 the "TZ" environment variable permanent;
5478 * incorporate the table changes by Paul Eggert;
5480 * include (and document) support for universal time specifications in
5481 data files - but do not (yet) include use of this feature in the
5484 Think of this as "TZ Classic" - the software has been set up not to break if
5485 universal time shows up in its input, and data entries have been
5486 left as is so as not to break existing implementations.
5489 Release data94f - 1994-08-20 12:56:09 -0400
5491 (with thanks!) the latest data updates from Paul Eggert
5494 Release data94e - 1994-06-04 13:13:53 -0400
5499 Release code94g - 1994-05-05 12:14:07 -0400
5501 fix missing "optind.c" and a reference to it in the Makefile
5504 Release code94f - 1994-05-05 13:00:33 -0000
5505 [tzcode94f.tar.gz is missing!]
5507 changes to avoid overflow in difftime, as well as changes to cope
5508 with the 52/53 challenge in strftime
5511 Release code94e - 1994-03-30 23:32:59 -0500
5513 change for the benefit of PCTS
5516 Release 94d - 1994-02-24 15:42:25 -0500
5518 Avoid clashes with POSIX semantics for zones such as GMT+4.
5520 Some other very minor housekeeping is also present.
5523 Release code94c - 1994-02-10 08:52:40 -0500
5525 Fix bug where mkdirs was broken unless you compile with
5526 -fwritable-strings (which is generally losing to do).
5529 Release 94b - 1994-02-07 10:04:33 -0500
5531 work by Paul Eggert who notes:
5533 I found another book of time zone histories by E W Whitman; it's not
5534 as extensive as Shanks but has a few goodies of its own. I used it
5535 to update the tables. I also fixed some more as a result of
5536 correspondence with Adam David and Peter Ilieve, and move some stray
5537 links from 'europe' to 'backward'. I corrected some scanning errors
5540 As far as the code goes, I fixed zic to allow years in the range
5541 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5542 And I cleaned up the zic documentation a little bit.
5545 Release data94a - 1994-02-03 08:58:54 -0500
5547 It simply incorporates the recently announced leap second into the
5551 Release 93g - 1993-11-22 17:28:27 -0500
5553 Paul Eggert has provided a good deal of historic information (based
5554 on Shanks), and there are some code changes to deal with the buglets
5555 that crawled out in dealing with the new information.
5558 Release 93f - 1993-10-15 12:27:46 -0400
5560 Paul Eggert's changes
5563 Release 93e - 1993-09-05 21:21:44 -0400
5565 This has updated data for Israel, England, and Kwajalein. There's
5566 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5567 Thanks to Paul Eggert and Peter Ilieve for the changes.
5570 Release 93d - 1993-06-17 23:34:17 -0400
5572 new fix and new data on Israel
5575 Release 93c - 1993-06-06 19:31:55 -0400
5580 Release 93b - 1993-02-02 14:53:58 -0500
5582 updated "leapseconds" file
5585 Release 93 - 1993-01-08 07:01:06 -0500
5587 At kre's suggestion, the package has been split in two - a code piece
5588 (which also includes documentation) that's only of use to folks who
5589 want to recompile things and a data piece useful to anyone who can
5592 The new version has a few changes to the data files, a few
5593 portability changes, and an off-by-one fix (with thanks to
5594 Tom Karzes at deshaw.com for providing a description and a
5598 Release 92c - 1992-11-21 17:35:36 -0000
5599 [tz92c.tar.Z is missing!]
5601 The fallout from the latest round of DST transitions.
5603 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5604 there's also a change to "zic.c" that makes it portable to more systems.
5607 Release 92 - 1992-04-25 18:17:03 -0000
5608 [tz92.tar.Z is missing!]
5610 By popular demand (well, at any rate, following a request by kre at munnari)
5613 The 1989 update of the time zone package featured:
5615 * POSIXization (including interpretation of POSIX-style TZ environment
5616 variables, provided by Guy Harris),
5617 * ANSIfication (including versions of "mktime" and "difftime"),
5618 * SVIDulation (an "altzone" variable)
5619 * MACHination (the "gtime" function)
5620 * corrections to some time zone data (including corrections to the rules
5621 for Great Britain and New Zealand)
5622 * reference data from the United States Naval Observatory for folks who
5623 want to do additional time zones
5624 * and the 1989 data for Saudi Arabia.
5626 (Since this code will be treated as "part of the implementation" in some
5627 places and as "part of the application" in others, there's no good way to
5628 name functions, such as timegm, that are not part of the proposed ANSI C
5629 standard; such functions have kept their old, underscore-free names in this
5632 And the "dysize" function has disappeared; it was present to allow
5633 compilation of the "date" command on old BSD systems, and a version of "date"
5634 is now provided in the package. The "date" command is not created when you
5635 "make all" since it may lack options provided by the version distributed with
5636 your operating system, or may not interact with the system in the same way
5637 the native version does.
5639 Since POSIX frowns on correct leap second handling, the default behavior of
5640 the "zic" command (in the absence of a "-L" option) has been changed to omit
5641 leap second information from its output files.
5647 This file contains copies of the part of each release announcement
5648 that talks about the changes in that release. The text has been
5649 adapted and reformatted for the purposes of this file.
5651 Traditionally a release R consists of a pair of tarball files,
5652 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5653 code2010a, data2012c) consist of just one or the other tarball, and a
5654 few (e.g., code2012c-data2012d) have tarballs with mixed version
5655 numbers. Recent releases also come in an experimental format
5656 consisting of a single tarball tzdb-R.tar.lz with extra data.
5658 Release timestamps are taken from the release's commit (for newer,
5659 Git-based releases), from the newest file in the tarball (for older
5660 releases, where this info is available) or from the email announcing
5661 the release (if all else fails; these are marked with a time zone
5662 abbreviation of -0000 and an "is missing!" comment).
5664 Earlier versions of the code and data were not announced on the tz
5665 list and are not summarized here.
5667 This file is in the public domain.