1 News for the tz database
3 Release 2022f - 2022-10-28 18:04:57 -0700
6 Mexico will no longer observe DST except near the US border.
7 Chihuahua moves to year-round -06 on 2022-10-30.
8 Fiji no longer observes DST.
9 Move links to 'backward'.
10 In vanguard form, GMT is now a Zone and Etc/GMT a link.
11 zic now supports links to links, and vanguard form uses this.
12 Simplify four Ontario zones.
13 Fix a Y2438 bug when reading TZif data.
14 Enable 64-bit time_t on 32-bit glibc platforms.
15 Omit large-file support when no longer needed.
16 In C code, use some C23 features if available.
17 Remove no-longer-needed workaround for Qt bug 53071.
19 Changes to future timestamps.
21 Mexico will no longer observe DST after 2022, except for areas
22 near the US border that continue to observe US DST rules.
23 On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
24 from -07 (-06 with DST) to year-round -06, thus not changing
25 its clocks that day. The new law states that Chihuahua
26 near the US border no longer observes US DST.
28 Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.)
29 For now, assume DST is suspended indefinitely.
33 Move links to 'backward' to ease and simplify link maintenance.
34 This affects generated data only if you use 'make BACKWARD='.
36 GMT is now a Zone and Etc/GMT a link instead of vice versa,
37 as GMT is needed for leap second support whereas Etc/GMT is not.
38 However, this change exposes a bug in TZUpdater 2.3.2 so it is
39 present only in vanguard form for now.
41 Vanguard form now uses links to links, as zic now supports this.
43 Changes to past timestamps
45 Simplify four Ontario zones, as most of the post-1970 differences
46 seem to have been imaginary. (Problem reported by Chris Walton.)
47 Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay
48 to 'backzone'; backward-compatibility links still work, albeit
49 with some different timestamps before November 2005.
53 zic now supports links to links regardless of input line order.
54 For example, if Australia/Sydney is a Zone, the lines
55 Link Australia/Canberra Australia/ACT
56 Link Australia/Sydney Australia/Canberra
57 now work correctly, even though the shell commands
58 ln Australia/Canberra Australia/ACT
59 ln Australia/Sydney Australia/Canberra
60 would fail because the first command attempts to use a link
61 Australia/Canberra that does not exist until after the second
62 command is executed. Previously, zic had unspecified behavior if
63 a Link line's target was another link, and zic often misbehaved if
64 a Link line's target was a later Link line.
66 Fix line number in zic's diagnostic for a link to a link.
68 Fix a bug that caused localtime to mishandle timestamps starting
69 in the year 2438 when reading data generated by 'zic -b fat' when
70 distant-future DST transitions occur at times given in standard
71 time or in UT, not the usual case of local time. This occurs when
72 the corresponding .zi Rule lines specify DST transitions with TO
73 columns of 'max' and AT columns that end in 's' or 'u'. The
74 number 2438 comes from the 32-bit limit in the year 2038, plus the
75 400-year Gregorian cycle. (Problem reported by Bradley White.)
77 On glibc 2.34 and later, which optionally supports 64-bit time_t
78 on platforms like x86 where time_t was traditionally 32 bits,
79 default time_t to 64 instead of 32 bits. This lets functions like
80 localtime support timestamps after the year 2038, and fixes
81 year-2038 problems in zic when accessing files dated after 2038.
82 To continue to limit time_t to 32 bits on these platforms, use
83 "make CFLAGS='-D_TIME_BITS=32'".
85 In C code, do not enable large-file support on platforms like AIX
86 and macOS that no longer need it now that tzcode does not use
87 off_t or related functions like 'stat'. Large-file support is
88 still enabled by default on GNU/Linux, as it is needed for 64-bit
91 In C code, prefer C23 keywords to pre-C23 macros for alignof,
92 bool, false, and true. Also, use the following C23 features if
93 available: __has_include, unreachable.
95 zic no longer works around Qt bug 53071, as the relevant Qt
96 releases have been out of support since 2019. This change affects
97 only fat TZif files, as thin files never had the workaround.
99 zdump no longer modifies the environ vector when compiled on
100 platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
101 This avoid undefined behavior on POSIX platforms.
104 Release 2022e - 2022-10-11 11:13:02 -0700
107 Jordan and Syria switch from +02/+03 with DST to year-round +03.
109 Changes to future timestamps
111 Jordan and Syria are abandoning the DST regime and are changing to
112 permanent +03, so they will not fall back from +03 to +02 on
113 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.)
115 Changes to past timestamps
117 On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00.
119 Changes to past time zone abbreviations and DST flags
121 The temporary advancement of clocks in central Mexico in summer
122 1931 is now treated as daylight saving time, instead of as two
123 changes to standard time.
126 Release 2022d - 2022-09-23 12:02:57 -0700
129 Palestine transitions are now Saturdays at 02:00.
130 Simplify three Ukraine zones into one.
132 Changes to future timestamps
134 Palestine now springs forward and falls back at 02:00 on the
135 first Saturday on or after March 24 and October 24, respectively.
136 This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00.
137 (Thanks to Heba Hamad.)
139 Changes to past timestamps
141 Simplify three Ukraine zones to one, since the post-1970
142 differences seem to have been imaginary. Move Europe/Uzhgorod and
143 Europe/Zaporozhye to 'backzone'; backward-compatibility links
144 still work, albeit with different timestamps before October 1991.
147 Release 2022c - 2022-08-15 17:47:18 -0700
150 Work around awk bug in FreeBSD, macOS, etc.
151 Improve tzselect on intercontinental Zones.
155 Work around a bug in onetrueawk that broke commands like
156 'make traditional_tarballs' on FreeBSD, macOS, etc.
157 (Problem reported by Deborah Goldsmith.)
159 Add code to tzselect that uses experimental structured comments in
160 zone1970.tab to clarify whether Zones like Africa/Abidjan and
161 Europe/Istanbul cross continent or ocean boundaries.
162 (Inspired by a problem reported by Peter Krefting.)
164 Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
165 directory /a/b already exists.
167 Remove zoneinfo2tdf.pl, as it was unused and triggered false
168 malware alarms on some email servers.
171 Release 2022b - 2022-08-10 15:38:32 -0700
174 Chile's DST is delayed by a week in September 2022.
175 Iran no longer observes DST after 2022.
176 Rename Europe/Kiev to Europe/Kyiv.
178 Vanguard form now uses %z.
179 Finish moving duplicate-since-1970 zones to 'backzone'.
180 New build option PACKRATLIST
181 New tailored_tarballs target, replacing rearguard_tarballs
183 Changes to future timestamps
185 Chile's 2022 DST start is delayed from September 4 to September 11.
186 (Thanks to Juan Correa.)
188 Iran plans to stop observing DST permanently, after it falls back
189 on 2022-09-21. (Thanks to Ali Mirjamali.)
191 Changes to past timestamps
193 Finish moving to 'backzone' the location-based zones whose
194 timestamps since 1970 are duplicates; adjust links accordingly.
195 This change ordinarily affects only pre-1970 timestamps, and with
196 the new PACKRATLIST option it does not affect any timestamps.
197 In this round the affected zones are Antarctica/Vostok,
198 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
199 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
200 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
201 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
202 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
203 Pacific/Wake and Pacific/Wallis, and the affected links are
204 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
205 Pacific/Truk, and Pacific/Yap.
207 From fall 1994 through fall 1995, Shanks wrote that Crimea's
208 DST transitions were at 02:00 standard time, not at 00:00.
209 (Thanks to Michael Deckers.)
211 Iran adopted standard time in 1935, not 1946. In 1977 it observed
212 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
213 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
214 transition was on 05-27, not 03-21.
215 (Thanks to Roozbeh Pournader and Francis Santoni.)
217 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
218 considered DST, not standard time. Santiago and environs had moved
219 their clocks back to rejoin the rest of mainland Chile; put this
220 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
222 Some old, small clock transitions have been removed, as people at
223 the time did not change their clocks. This affects Asia/Hong_Kong
224 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
228 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
229 English now. Spelling of other names in Ukraine has not yet
230 demonstrably changed in common English practice so for now these
231 names retain old spellings, as in other countries (e.g.,
232 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
236 zic has a new option '-R @N' to output explicit transitions < N.
237 (Need suggested by Almaz Mingaleev.)
239 'zic -r @N' no longer outputs bad data when N < first transition.
240 (Problem introduced in 2021d and reported by Peter Krefting.)
242 zic now checks its input for NUL bytes and unterminated lines, and
243 now supports input line lengths up to 2048 (not 512) bytes.
245 gmtime and related code now use the abbreviation "UTC" not "GMT".
246 POSIX is being revised to require this.
248 When tzset and related functions set vestigial static variables
249 like tzname, they now prefer specified timestamps to unspecified ones.
250 (Problem reported by Almaz Mingaleev.)
252 zic no longer complains "can't determine time zone abbreviation to
253 use just after until time" when a transition to a new standard
254 time occurs simultaneously with the first DST fallback transition.
256 Changes to build procedure
258 Source data in vanguard form now uses the %z notation, introduced
259 in release 2015f. For example, for America/Sao_Paulo vanguard
260 form contains the zone continuation line "-3:00 Brazil %z", which
261 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
262 used in main and rearguard forms. The plan is for the main form
263 to use %z eventually; in the meantime maintainers of zi parsers
264 are encouraged to test the parsers on vanguard.zi.
266 The Makefile has a new PACKRATLIST option to select a subset of
267 'backzone'. For example, 'make PACKRATDATA=backzone
268 PACKRATLIST=zone.tab' now generates TZif files identical to those
269 of the global-tz project.
271 The Makefile has a new tailored_tarballs target for generating
272 special-purpose tarballs. It generalizes and replaces the
273 rearguard_tarballs target and related targets and macros, which
276 'make install' now defaults LOCALTIME to Factory not GMT,
277 which means the default abbreviation is now "-00" not "GMT".
279 Remove the posix_packrat target, marked obsolescent in 2016a.
282 Release 2022a - 2022-03-15 23:02:01 -0700
285 Palestine will spring forward on 2022-03-27, not -03-26.
286 zdump -v now outputs better failure indications.
287 Bug fixes for code that reads corrupted TZif data.
289 Changes to future timestamps
291 Palestine will spring forward on 2022-03-27, not 2022-03-26.
292 (Thanks to Heba Hamad.) Predict future transitions for first
293 Sunday >= March 25. Additionally, predict fallbacks to be the first
294 Friday on or after October 23, not October's last Friday, to be more
295 consistent with recent practice. The first differing fallback
296 prediction is on 2025-10-24, not 2025-10-31.
298 Changes to past timestamps
300 From 1992 through spring 1996, Ukraine's DST transitions were at
301 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
303 Chile's Santiago Mean Time and its LMT precursor have been adjusted
304 eastward by 1 second to align with past and present law.
306 Changes to commentary
308 Add several references for Chile's 1946/1947 transitions, some of
309 which only affected portions of the country.
313 Fix bug when mktime gets confused by truncated TZif files with
314 unspecified local time. (Problem reported by Almaz Mingaleev.)
316 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
317 (Problem reported by Christos Zoulas.)
319 When reading a version 2 or later TZif file, the TZif reader now
320 validates the version 1 header and data block only enough to skip
321 over them, as recommended by RFC 8536 section 4. Also, the TZif
322 reader no longer mistakenly attempts to parse a version 1 TZIf
323 file header as a TZ string.
325 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
326 when local time and UT cannot be determined for a timestamp.
328 Changes to build procedure
330 Distribution tarballs now use standard POSIX.1-1988 ustar format
331 instead of GNU format. Although the formats are almost identical
332 for these tarballs, ustar headers' magic fields contain "ustar"
333 instead of "ustar ", and their version fields contain "00" instead
334 of " ". The two formats are planned to diverge more significantly
335 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
336 format becomes obsolete and the tarballs switch to pax format, an
337 extension of ustar. For details about these formats, please see
338 "pax - portable archive interchange", IEEE Std 1003.1-2017,
339 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
342 Release 2021e - 2021-10-21 18:41:00 -0700
344 Changes to future timestamps
346 Palestine will fall back 10-29 (not 10-30) at 01:00.
347 (Thanks to P Chan and Heba Hemad.)
350 Release 2021d - 2021-10-15 13:48:18 -0700
353 Fiji suspends DST for the 2021/2022 season.
354 'zic -r' marks unspecified timestamps with "-00".
356 Changes to future timestamps
358 Fiji will suspend observance of DST for the 2021/2022 season.
359 Assume for now that it will return next year. (Thanks to Jashneel
364 'zic -r' now uses "-00" time zone abbreviations for intervals
365 with UT offsets that are unspecified due to -r truncation.
366 This implements a change in draft Internet RFC 8536bis.
369 Release 2021c - 2021-10-01 14:21:49 -0700
372 Revert most 2021b changes to 'backward'.
373 Fix 'zic -b fat' bug in pre-1970 32-bit data.
374 Fix two Link line typos.
375 Distribute SECURITY file.
377 This release is intended as a bugfix release, to fix compatibility
378 problems and typos reported since 2021b was released.
380 Changes to Link directives
382 Revert almost all of 2021b's changes to the 'backward' file,
383 by moving Link directives back to where they were in 2021a.
384 Although 'zic' doesn't care which source file contains a Link
385 directive, some downstream uses ran into trouble with the move.
386 (Problem reported by Stephen Colebourne for Joda-Time.)
388 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
389 (problem reported by Chris Walton).
391 Fix 'backzone' typo that linked America/Virgin to the wrong
392 location (problem reported by Michael Deckers).
396 Fix a bug in 'zic -b fat' that caused old timestamps to be
397 mishandled in 32-bit-only readers (problem reported by Daniel
400 Changes to documentation
402 Distribute the SECURITY file (problem reported by Andreas Radke).
405 Release 2021b - 2021-09-24 16:23:00 -0700
408 Jordan now starts DST on February's last Thursday.
409 Samoa no longer observes DST.
410 Merge more location-based Zones whose timestamps agree since 1970.
411 Move some backward-compatibility links to 'backward'.
412 Rename Pacific/Enderbury to Pacific/Kanton.
413 Correct many pre-1993 transitions in Malawi, Portugal, etc.
414 zic now creates each output file or link atomically.
415 zic -L no longer omits the POSIX TZ string in its output.
416 zic fixes for truncation and leap second table expiration.
417 zic now follows POSIX for TZ strings using all-year DST.
418 Fix some localtime crashes and bugs in obscure cases.
419 zdump -v now outputs more-useful boundary cases.
420 tzfile.5 better matches a draft successor to RFC 8536.
423 This release is prompted by recent announcements by Jordan and Samoa.
424 It incorporates many other changes that had accumulated since 2021a.
425 However, it omits most proposed changes that merged all Zones
426 agreeing since 1970, as concerns were raised about doing too many of
427 these changes at once. It does keeps some of these changes in the
428 interest of making tzdb more equitable one step at a time; see
429 "Merge more location-based Zones" below.
431 Changes to future timestamps
433 Jordan now starts DST on February's last Thursday.
434 (Thanks to Steffen Thorsen.)
436 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
440 Rename Pacific/Enderbury to Pacific/Kanton. When we added
441 Enderbury in 1993, we did not know that it is uninhabited and that
442 Kanton (population two dozen) is the only inhabited location in
443 that timezone. The old name is now a backward-compatibility link.
445 Changes to past timestamps
447 Correct many pre-1993 transitions, fixing entries originally
448 derived from Shanks, Whitman, and Mundell. The fixes include:
449 - Barbados: standard time was introduced in 1911, not 1932; and
450 DST was observed in 1942-1944
451 - Cook Islands: In 1899 they switched from east to west of GMT,
452 celebrating Christmas for two days. They (and Niue) switched
453 to standard time in 1952, not 1901.
454 - Guyana: corrected LMT for Georgetown; the introduction of
455 standard time in 1911, not 1915; and corrections to 1975 and
457 - Kanton: uninhabited before 1937-08-31
458 - Niue: only observed -11:20 from 1952 through 1964, then went to
459 -11 instead of -11:30
460 - Portugal: DST was observed in 1950
461 - Tonga: corrected LMT; the introduction of standard time in 1945,
462 not 1901; and corrections to the transition from +12:20 to +13
464 Additional fixes to entries in the 'backzone' file include:
465 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
466 - The Gambia: 1933 and 1942 transitions
467 - Malawi: several 1911 through 1925 transitions
468 - Sierra Leone: several 1913 through 1941 transitions, and DST
469 was NOT observed in 1957 through 1962
470 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
473 Merge more location-based Zones whose timestamps agree since 1970,
474 as pre-1970 timestamps are out of scope. This is part of a
475 process that has been ongoing since 2013. This does not affect
476 post-1970 timestamps, and timezone historians who build with 'make
477 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
478 When merging, keep the most-populous location's data, and move
479 data for other locations to 'backzone' with a backward
480 link in 'backward'. For example, move America/Creston data to
481 'backzone' with a link in 'backward' from America/Phoenix because
482 the two timezones' timestamps agree since 1970; this change
483 affects some pre-1968 timestamps in America/Creston because
484 Creston and Phoenix disagreed before 1968. The affected Zones
485 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
486 America/Creston, America/Curacao, America/Nassau,
487 America/Port_of_Spain, Antarctica/DumontDUrville, and
490 Changes to maintenance procedure
492 The new file SECURITY covers how to report security-related bugs.
494 Several backward-compatibility links have been moved to the
495 'backward' file. These links, which range from Africa/Addis_Ababa
496 to Pacific/Saipan, are only for compatibility with now-obsolete
497 guidelines suggesting an entry for every ISO 3166 code.
498 The intercontinental convenience links Asia/Istanbul and
499 Europe/Nicosia have also been moved to 'backward'.
503 zic now creates each output file or link atomically,
504 possibly by creating a temporary file and then renaming it.
505 This avoids races where a TZ setting would temporarily stop
506 working while zic was installing a replacement file or link.
508 zic -L no longer omits the POSIX TZ string in its output.
509 Starting with 2020a, zic -L truncated its output according to the
510 "Expires" directive or "#expires" comment in the leapseconds file.
511 The resulting TZif files omitted daylight saving transitions after
512 the leap second table expired, which led to far less-accurate
513 predictions of times after the expiry. Although future timestamps
514 cannot be converted accurately in the presence of leap seconds, it
515 is more accurate to convert near-future timestamps with a few
516 seconds error than with an hour error, so zic -L no longer
517 truncates output in this way.
519 Instead, when zic -L is given the "Expires" directive, it now
520 outputs the expiration by appending a no-change entry to the leap
521 second table. Although this should work well with most TZif
522 readers, it does not conform to Internet RFC 8536 and some pickier
523 clients (including tzdb 2017c through 2021a) reject it, so
524 "Expires" directives are currently disabled by default. To enable
525 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
526 this new feature it is marked with a new TZif version number 4,
527 a format intended to be documented in a successor to RFC 8536.
529 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
530 that omits leap second information for the range LO..B when LO
531 falls between two leap seconds A and B. Instead, it generates a
532 TZif version 4 file that represents the previously-missing
535 The TZif reader now allows the leap second table to begin with a
536 correction other than -1 or +1, and to contain adjacent
537 transitions with equal corrections. This supports TZif version 4.
539 The TZif reader now lets leap seconds occur less than 28 days
540 apart. This supports possible future TZif extensions.
542 Fix bug that caused 'localtime' etc. to crash when TZ was
543 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
544 not conform to POSIX but does conform to Internet RFC 8536.
546 Fix another bug that caused 'localtime' etc. to crash when TZ was
547 set to a POSIX-conforming but unusual TZ string like
548 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
550 Fix yet another bug that caused 'localtime' etc. to mishandle slim
551 TZif files containing leap seconds after the last explicit
552 transition in the table, or when handling far-future timestamps
553 in slim TZif files lacking leap seconds.
555 Fix localtime misbehavior involving positive leap seconds.
556 This change affects only behavior for "right" system time,
557 which contains leap seconds, and only if the UT offset is
558 not a multiple of 60 seconds when a positive leap second occurs.
559 (No such timezone exists in tzdb, luckily.) Without the fix,
560 the timestamp was ambiguous during a positive leap second.
561 With the fix, any seconds occurring after a positive leap second
562 and within the same localtime minute are counted through 60, not
563 through 59; their UT offset (tm_gmtoff) is the same as before.
564 Here is how the fix affects timestamps in a timezone with UT
565 offset +01:23:45 (5025 seconds) and with a positive leap second at
566 1972-06-30 23:59:60 UTC (78796800):
568 time_t without the fix with the fix
569 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
570 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
572 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
573 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
575 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
576 civil time changes a few seconds before time_t wraps around, when
577 leap seconds are enabled.
579 Fix bug in zic -r; in some cases, the dummy time type after the
580 last time transition disagreed with the TZ string, contrary to
581 Internet RFC 8563 section 3.3.
583 Fix a bug with 'zic -r @X' when X is a negative leap second that
584 has a nonnegative correction. Without the fix, the output file
585 was truncated so that X appeared to be a positive leap second.
586 Fix a similar, even-less-likely bug when truncating at a positive
587 leap second that has a nonpositive correction.
589 zic -r now reports an error if given rolling leap seconds, as this
590 usage has never generally worked and is evidently unused.
592 zic now generates a POSIX-conforming TZ string for TZif files
593 where all-year DST is predicted for the indefinite future.
594 For example, for all-year Eastern Daylight Time, zic now generates
595 "XXX3EDT4,0/0,J365/23" where it previously generated
596 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
597 noting the possibility of POSIX conformance.)
599 zic.c no longer requires sys/wait.h (thanks to spazmodius for
600 noting it wasn't needed).
602 When reading slim TZif files, zdump no longer mishandles leap
603 seconds on the rare platforms where time_t counts leap seconds,
604 fixing a bug introduced in 2014g.
606 zdump -v now outputs timestamps at boundaries of what localtime
607 and gmtime can represent, instead of the less-useful timestamps
608 one day after the minimum and one day before the maximum.
609 (Thanks to Arthur David Olson for prototype code, and to Manuela
610 Friedrich for debugging help.)
612 zdump's -c and -t options are now consistently inclusive for the
613 lower time bound and exclusive for the upper. Formerly they were
614 inconsistent. (Confusion noted by Martin Burnicki.)
616 Changes to build procedure
618 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
619 non-POSIX hosts where malloc doesn't set errno.
620 (Problem reported by Jan Engelhardt.)
622 Changes to documentation
624 tzfile.5 better matches a draft successor to RFC 8536
625 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
628 Release 2021a - 2021-01-24 10:54:57 -0800
630 Changes to future timestamps
632 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
633 (Thanks to Steffen Thorsen.)
636 Release 2020f - 2020-12-29 00:17:46 -0800
638 Change to build procedure
640 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
641 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
644 Release 2020e - 2020-12-22 15:14:34 -0800
647 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
649 Changes to future timestamps
651 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
652 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
654 Changes to past timestamps
656 Correct many pre-1986 transitions, fixing entries originally
657 derived from Shanks. The fixes include:
658 - Australia: several 1917 through 1971 transitions
659 - The Bahamas: several 1941 through 1945 transitions
660 - Bermuda: several 1917 through 1956 transitions
661 - Belize: several 1942 through 1968 transitions
662 - Ghana: several 1915 through 1956 transitions
663 - Israel and Palestine: several 1940 through 1985 transitions
664 - Kenya and adjacent: several 1908 through 1960 transitions
665 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
666 through 1919 transitions
667 - Seychelles: the introduction of standard time in 1907, not 1906
668 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
671 Because of the Australia change, Australia/Currie (King Island) is
672 no longer needed, as it is identical to Australia/Hobart for all
673 timestamps since 1970 and was therefore created by mistake.
674 Australia/Currie has been moved to the 'backward' file and its
675 corrected data moved to the 'backzone' file.
677 Changes to past time zone abbreviations and DST flags
679 To better match legislation in Turks and Caicos, the 2015 shift to
680 year-round observance of -04 is now modeled as AST throughout before
681 returning to Eastern Time with US DST in 2018, rather than as
682 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
684 Changes to documentation
686 The zic man page now documents zic's coalescing of transitions
687 when a zone falls back just before DST springs forward.
690 Release 2020d - 2020-10-21 11:24:13 -0700
693 Palestine ends DST earlier than predicted, on 2020-10-24.
695 Changes to past and future timestamps
697 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
698 as previously predicted (thanks to Sharef Mustafa.) Its
699 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
700 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
701 its spring 2020 transition was on March 28 at 00:00, not March 27
702 (thanks to Pierre Cashon.) This affects Asia/Gaza and
703 Asia/Hebron. Assume future spring and fall transitions will be on
704 the Saturday preceding the last Sunday of March and October,
708 Release 2020c - 2020-10-16 11:15:53 -0700
711 Fiji starts DST later than usual, on 2020-12-20.
713 Changes to future timestamps
715 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
716 previously predicted. DST will still end on 2021-01-17.
717 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
718 the later-than-usual start date is a one-time departure from the
721 Changes to build procedure
723 Rearguard tarballs now contain an empty file pacificnew.
724 Some older downstream software expects this file to exist.
725 (Problem reported by Mike Cullinan.)
728 Release 2020b - 2020-10-06 18:35:04 -0700
731 Revised predictions for Morocco's changes starting in 2023.
732 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
733 Macquarie Island has stayed in sync with Tasmania since 2011.
734 Casey, Antarctica is at +08 in winter and +11 in summer.
735 zic no longer supports -y, nor the TYPE field of Rules.
737 Changes to future timestamps
739 Morocco's spring-forward after Ramadan is now predicted to occur
740 no sooner than two days after Ramadan, instead of one day.
741 (Thanks to Milamber.) The first altered prediction is for 2023,
742 now predicted to spring-forward on April 30 instead of April 23.
744 Changes to past and future timestamps
746 Casey Station, Antarctica has been using +08 in winter and +11 in
747 summer since 2018. The most recent transition from +08 to +11 was
748 2020-10-04 00:01. Also, Macquarie Island has been staying in
749 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
751 Changes to past and future time zone abbreviations and DST flags
753 Canada's Yukon, represented by America/Whitehorse and
754 America/Dawson, changes its time zone rules from -08/-07 to
755 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
756 This change affects only the time zone abbreviation (MST vs PDT)
757 and daylight saving flag for the period between the two dates.
758 (Thanks to Andrew G. Smith.)
760 Changes to past timestamps
762 Correct several transitions for Hungary for 1918/1983.
763 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
764 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
765 time was on 11-01, not 10-01 (thanks to Michael Deckers).
767 The 1891 French transition was on March 16, not March 15. The
768 1911-03-11 French transition was at midnight, not a minute later.
769 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
770 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
774 Support for zic's long-obsolete '-y YEARISTYPE' option has been
775 removed and, with it, so has support for the TYPE field in Rule
776 lines, which is now reserved for compatibility with earlier zic.
777 These features were previously deprecated in release 2015f.
778 (Thanks to Tim Parenti.)
780 zic now defaults to '-b slim' instead of to '-b fat'.
782 zic's new '-l -' and '-p -' options uninstall any existing
783 localtime and posixrules files, respectively.
785 The undocumented and ineffective tzsetwall function has been
788 Changes to build procedure
790 The Makefile now defaults POSIXRULES to '-', so the posixrules
791 feature (obsolete as of 2019b) is no longer installed by default.
793 Changes to documentation and commentary
795 The long-obsolete files pacificnew, systemv, and yearistype.sh have
796 been removed from the distribution. (Thanks to Tim Parenti.)
799 Release 2020a - 2020-04-23 16:03:47 -0700
802 Morocco springs forward on 2020-05-31, not 2020-05-24.
803 Canada's Yukon advanced to -07 year-round on 2020-03-08.
804 America/Nuuk renamed from America/Godthab.
805 zic now supports expiration dates for leap second lists.
807 Changes to future timestamps
809 Morocco's second spring-forward transition in 2020 will be May 31,
810 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
811 Adjust future-year predictions to use the first Sunday after the
812 day after Ramadan, not the first Sunday after Ramadan.
814 Canada's Yukon, represented by America/Whitehorse and
815 America/Dawson, advanced to -07 year-round, beginning with its
816 spring-forward transition on 2020-03-08, and will not fall back on
817 2020-11-01. Although a government press release calls this
818 "permanent Pacific Daylight Saving Time", we prefer MST for
819 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
820 (Thanks to Tim Parenti.)
822 Changes to past timestamps
824 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
826 Changes to timezone identifiers
828 To reflect current usage in English better, America/Godthab has
829 been renamed to America/Nuuk. A backwards-compatibility link
830 remains for the old name.
834 localtime.c no longer mishandles timestamps after the last
835 transition in a TZif file with leap seconds and with daylight
836 saving time transitions projected into the indefinite future.
837 For example, with TZ='America/Los_Angeles' with leap seconds,
838 zdump formerly reported a DST transition on 2038-03-14
839 from 01:59:32.999... to 02:59:33 instead of the correct transition
840 from 01:59:59.999... to 03:00:00.
842 zic -L now supports an Expires line in the leapseconds file, and
843 truncates the TZif output accordingly. This propagates leap
844 second expiration information into the TZif file, and avoids the
845 abovementioned localtime.c bug as well as similar bugs present in
846 many client implementations. If no Expires line is present, zic
847 -L instead truncates the TZif output based on the #expires comment
848 present in leapseconds files distributed by tzdb 2018f and later;
849 however, this usage is obsolescent. For now, the distributed
850 leapseconds file has an Expires line that is commented out, so
851 that the file can be fed to older versions of zic which ignore the
852 commented-out line. Future tzdb distributions are planned to
853 contain a leapseconds file with an Expires line.
855 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
856 set to 1 if the system library supports the feature, and 2 if not.
857 As before, these macros are nonzero if tzcode should support the
858 feature, zero otherwise.
860 The configuration macro ALTZONE now has the same values with the
861 same meaning as HAVE_TZNAME and USG_COMPAT.
863 The code's defense against CRLF in leap-seconds.list is now
864 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
866 Although the undocumented tzsetwall function is not changed in
867 this release, it is now deprecated in preparation for removal in
868 future releases. Due to POSIX requirements, tzsetwall has not
869 worked for some time. Any code that uses it should instead use
870 tzalloc(NULL) or, if portability trumps thread-safety, should
871 unset the TZ environment variable.
873 Changes to commentary
875 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
876 following America/Halifax, and comments about Yukon's "south" and
877 "north" have been corrected to say "east" and "west". (Thanks to
881 Release 2019c - 2019-09-11 08:59:48 -0700
884 Fiji observes DST from 2019-11-10 to 2020-01-12.
885 Norfolk Island starts observing Australian-style DST.
887 Changes to future timestamps
889 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
890 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
891 Adjust future guesses accordingly.
893 Norfolk Island will observe Australian-style DST starting in
894 spring 2019. The first transition is on 2019-10-06. (Thanks to
895 Kyle Czech and Michael Deckers.)
897 Changes to past timestamps
899 Many corrections to time in Turkey from 1940 through 1985.
900 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
902 The Norfolk Island 1975-03-02 transition was at 02:00 standard
903 time, not 02:00 DST. (Thanks to Michael Deckers.)
905 South Korea observed DST from 1948 through 1951. Although this
906 info was supposed to appear in release 2014j, a typo inadvertently
907 suppressed the change. (Thanks to Alois Treindl.)
909 Detroit observed DST in 1967 and 1968 following the US DST rules,
910 except that its 1967 DST began on June 14 at 00:01. (Thanks to
911 Alois Treindl for pointing out that the old data entries were
914 Fix several errors in pre-1970 transitions in Perry County, IN.
915 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
917 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
918 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
919 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
920 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
921 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
922 Königsberg switched to +03 on 04-07 not 01-01.
924 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
925 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
926 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
928 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
929 (Thanks to Michael Deckers.)
931 Changes to past time zone abbreviations and DST flags
933 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
934 is now flagged as DST and is abbreviated HKWT not HKT.
938 leapseconds.awk now relies only on its input data, rather than
939 also relying on its comments. (Inspired by code from Dennis
940 Ferguson and Chris Woodbury.)
942 The code now defends against CRLFs in leap-seconds.list.
943 (Thanks to Brian Inglis and Chris Woodbury.)
945 Changes to documentation and commentary
947 theory.html discusses leap seconds. (Thanks to Steve Summit.)
949 Nashville's newspapers dueled about the time of day in the 1950s.
950 (Thanks to John Seigenthaler.)
952 Liechtenstein observed Swiss DST in 1941/2.
953 (Thanks to Alois Treindl.)
956 Release 2019b - 2019-07-01 00:09:53 -0700
959 Brazil no longer observes DST.
960 'zic -b slim' outputs smaller TZif files; please try it out.
961 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
963 Changes to future timestamps
965 Brazil has canceled DST and will stay on standard time indefinitely.
966 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
969 Predictions for Morocco now go through 2087 instead of 2037, to
970 work around a problem on newlib when using TZif files output by
971 zic 2019a or earlier. (Problem reported by David Gauchard.)
973 Changes to past and future timestamps
975 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
976 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
977 future transitions to be March's last Friday at 00:00.
979 Changes to past timestamps
981 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
982 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
983 not 09-15 at 00:00. In 1946 its spring-forward transition was on
984 04-21 at 00:00, not the previous day at 03:30. From 1946 through
985 1952 its fall-back transitions occurred at 04:30, not at 03:30.
986 In 1947 its fall-back transition was on 11-30, not 12-30.
989 Changes to past time zone abbreviations
991 Italy's 1866 transition to Rome Mean Time was on December 12, not
992 September 22. This affects only the time zone abbreviation for
993 Europe/Rome between those dates. (Thanks to Stephen Trainor and
996 Changes affecting metadata only
998 Add info about the Crimea situation in zone1970.tab and zone.tab.
999 (Problem reported by Serhii Demediuk.)
1003 zic's new -b option supports a way to control data bloat and to
1004 test for year-2038 bugs in software that reads TZif files.
1005 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
1006 for example, changing from fat to slim shrinks the Europe/London
1007 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
1008 files represent the same set of timestamps and use the same TZif
1009 format as documented in tzfile(5) and in Internet RFC 8536.
1010 Fat format attempts to work around bugs or incompatibilities in
1011 older software, notably software that mishandles 64-bit TZif data
1012 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
1013 Slim format is more efficient and does not work around 64-bit bugs
1014 or obsolete TZ strings. Currently zic defaults to fat format
1015 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
1016 out-of-the-box default is intended to change in future releases
1017 as the buggy software often mishandles timestamps anyway.
1019 zic no longer treats a set of rules ending in 2037 specially.
1020 Previously, zic assumed that such a ruleset meant that future
1021 timestamps could not be predicted, and therefore omitted a
1022 POSIX-like TZ string in the TZif output. The old behavior is no
1023 longer needed for current tzdata, and caused problems with newlib
1024 when used with older tzdata (reported by David Gauchard).
1026 zic no longer generates some artifact transitions. For example,
1027 Europe/London no longer has a no-op transition in January 1996.
1029 Changes to build procedure
1031 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
1034 Changes to documentation and commentary
1036 The Makefile now documents the POSIXRULES macro as being obsolete,
1037 and similarly, zic's -p POSIXRULES option is now documented as
1038 being obsolete. Although the POSIXRULES feature still exists and
1039 works as before, in practice it is rarely used for its intended
1040 purpose, and it does not work either in the default reference
1041 implementation (for timestamps after 2037) or in common
1042 implementations such as GNU/Linux (for contemporary timestamps).
1043 Since POSIXRULES was designed primarily as a temporary transition
1044 facility for System V platforms that died off decades ago, it is
1045 being decommissioned rather than institutionalized.
1047 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
1050 Release 2019a - 2019-03-25 22:01:33 -0700
1053 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
1054 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
1056 Changes to past and future timestamps
1058 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
1059 previously predicted. Adjust our prediction by guessing that spring
1060 transitions will be between 24 and 30 March, which matches recent practice
1061 since 2016. (Thanks to Even Scharning and Tim Parenti.)
1063 Metlakatla ended its observance of Pacific standard time,
1064 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
1065 Stanley and Tim Parenti.)
1067 Changes to past timestamps
1069 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
1070 (Thanks to Alois Treindl and Isaac Starkman.)
1072 Changes to time zone abbreviations
1074 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
1075 of being a separate zone that generates the abbreviation "UCT",
1076 which nowadays is typically a typo. (Problem reported by Isiah
1081 zic now has an -r option to limit the time range of output data.
1082 For example, 'zic -r @1000000000' limits the output data to
1083 timestamps starting 1000000000 seconds after the Epoch.
1084 This helps shrink output size and can be useful for applications
1085 not needing the full timestamp history, such as TZDIST truncation;
1086 see Internet RFC 8536 section 5.1. (Inspired by a feature request
1087 from Christopher Wong, helped along by bug reports from Wong and
1090 Changes to documentation
1092 Mention Internet RFC 8536 (February 2019), which documents TZif.
1094 tz-link.html now cites tzdata-meta
1095 <https://tzdata-meta.timtimeonline.com/>.
1098 Release 2018i - 2018-12-30 11:05:43 -0800
1101 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
1103 Changes to future timestamps
1105 Due to a change in government, São Tomé and Príncipe switches back
1106 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
1107 Nasardinov and Michael Deckers.)
1110 Release 2018h - 2018-12-23 17:59:32 -0800
1113 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
1114 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
1115 Metlakatla, Alaska observes PST this winter only.
1116 Guess Morocco will continue to adjust clocks around Ramadan.
1117 Add predictions for Iran from 2038 through 2090.
1119 Changes to future timestamps
1121 Guess that Morocco will continue to fall back just before and
1122 spring forward just after Ramadan, the practice since 2012.
1123 (Thanks to Maamar Abdelkader.) This means Morocco will observe
1124 negative DST during Ramadan in main and vanguard formats, and in
1125 rearguard format it stays in the +00 timezone and observes
1126 ordinary DST in all months other than Ramadan. As before, extend
1127 this guesswork to the year 2037. As a consequence, Morocco is
1128 scheduled to observe three DST transitions in some Gregorian years
1129 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
1132 The table of exact transitions for Iranian DST has been extended.
1133 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
1134 It now cuts off before 2091 as there is doubt about how the Persian
1135 calendar will treat 2091. This change predicts DST transitions in
1136 2038-9, 2042-3, and 2046-7 to occur one day later than previously
1137 predicted. As before, post-cutoff transitions are approximated.
1139 Changes to past and future timestamps
1141 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
1142 +05 on 2018-12-21. This is a zone split as Qostanay (aka
1143 Kostanay) did not switch, so create a zone Asia/Qostanay.
1145 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
1146 It did not change clocks that day and remains on -08 this winter.
1147 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
1148 rules next spring, so this change affects only timestamps
1149 from 2018-11-04 through 2019-03-10.
1151 Change to past timestamps
1153 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
1154 not 00:00. I transcribed the time incorrectly from Shanks.
1155 (Thanks to Phake Nick.)
1157 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
1158 (Thanks to Phake Nick.)
1160 Guam observed DST irregularly from 1959 through 1977.
1161 (Thanks to Phake Nick.)
1163 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
1164 10-01 changed standard time to +08:30 (not +08). Its transition
1165 back to +08 after WWII was on 1945-09-15, not the previous day.
1166 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
1167 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1168 its 1952 fallback was on 11-02 (not 10-25).
1170 This release contains many changes to timestamps before 1946 due
1171 to Japanese possession or occupation of Pacific/Chuuk,
1172 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1173 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1174 (Thanks to Phake Nick.)
1176 Assume that the Spanish East Indies was like the Philippines and
1177 observed American time until the end of 1844. This affects
1178 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1180 Changes to past tm_isdst flags
1182 For the recent Morocco change, the tm_isdst flag should be 1 from
1183 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1184 Give a URL to the official decree. (Thanks to Matt Johnson.)
1187 Release 2018g - 2018-10-26 22:22:45 -0700
1190 Morocco switches to permanent +01 on 2018-10-28.
1192 Changes to future timestamps
1194 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1195 so its clocks will not fall back as previously scheduled.
1196 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1200 When generating TZif files with leap seconds, zic no longer uses a
1201 format that trips up older 32-bit clients, fixing a bug introduced
1202 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1203 for QTBUG-53071 now also works for TZif files with leap seconds.
1205 The translator to rearguard format now rewrites the line
1206 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1207 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1208 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1209 and earlier. (Reported by Christos Zoulas.)
1211 Changes to past time zone abbreviations
1213 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1214 This reverts to 2011h, as the abbreviation change in 2011i was
1217 Changes to documentation
1219 tzfile.5 has new sections on interoperability issues.
1222 Release 2018f - 2018-10-18 00:14:18 -0700
1225 Volgograd moves from +03 to +04 on 2018-10-28.
1226 Fiji ends DST 2019-01-13, not 2019-01-20.
1227 Most of Chile changes DST dates, effective 2019-04-06.
1229 Changes to future timestamps
1231 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1232 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1234 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1235 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1238 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1239 time, and resume DST on the first Saturday in September at 24:00 mainland
1240 time. The changes are effective from 2019-04-06, and do not affect the
1241 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1242 and Tim Parenti.) Adjust future predictions accordingly.
1244 Changes to past timestamps
1246 The 2018-05-05 North Korea 30-minute time zone change took place
1247 at 23:30 the previous day, not at 00:00 that day.
1249 China's 1988 spring-forward transition was on April 17, not
1250 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1253 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1254 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1255 temporarily switched to +09/+10 during World War II. Macau
1256 observed DST in 1942/79, not 1961/80, and there were several
1257 errors for transition times and dates. (Thanks to P Chan.)
1259 The 1948-1951 fallback transitions in Japan were at 25:00 on
1260 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1261 zic turns this into 01:00 on the day after September's second
1262 Saturday, which is the best that POSIX or C platforms can do.
1264 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1265 paper by Li Yu, replacing more-questionable data from Shanks.
1267 Changes to time zone abbreviations
1269 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1273 zic now always generates TZif files where time type 0 is used for
1274 timestamps before the first transition. This simplifies the
1275 reading of TZif files and should not affect behavior of existing
1276 TZif readers because the same set of time types is used; only
1277 their internal indexes may have changed. This affects only the
1278 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1279 EET, which previously used nonzero types for these timestamps.
1281 Because of the type 0 change, zic no longer outputs a dummy
1282 transition at time -2**59 (before the Big Bang), as clients should
1283 no longer need this to handle historical timestamps correctly.
1284 This reverts a change introduced in 2013d and shrinks most TZif
1285 files by a few bytes.
1287 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1288 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1289 occurs at 18:00 on the Saturday before the last Sunday in April.
1290 This behavior was documented in 2018a but the code did not
1291 entirely match the documentation.
1293 localtime.c no longer requires at least one time type in TZif
1294 files that lack transitions or have a POSIX-style TZ string. This
1295 future-proofs the code against possible future extensions to the
1296 format that would allow TZif files with POSIX-style TZ strings and
1297 without transitions or time types.
1299 A read-access subscript error in localtime.c has been fixed.
1300 It could occur only in TZif files with timecnt == 0, something that
1301 does not happen in practice now but could happen in future versions.
1303 localtime.c no longer ignores TZif POSIX-style TZ strings that
1304 specify only standard time. Instead, these TZ strings now
1305 override the default time type for timestamps after the last
1306 transition (or for all timestamps if there are no transitions),
1307 just as DST strings specifying DST have always done.
1309 leapseconds.awk now outputs "#updated" and "#expires" comments,
1310 and supports leap seconds at the ends of months other than June
1311 and December. (Inspired by suggestions from Chris Woodbury.)
1313 Changes to documentation
1315 New restrictions: A Rule name must start with a character that
1316 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1317 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1318 The latter restriction makes room for future extensions (a
1319 possibility noted by Tom Lane).
1321 tzfile.5 now documents what time types apply before the first and
1322 after the last transition, if any.
1324 Documentation now uses the spelling "timezone" for a TZ setting
1325 that determines timestamp history, and "time zone" for a
1326 geographic region currently sharing the same standard time.
1328 The name "TZif" is now used for the tz binary data format.
1330 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1331 (Thanks to Aldrin Martoq for the link.)
1333 Changes to build procedure
1335 New 'make' target 'rearguard_tarballs' to build the rearguard
1336 tarball only. This is a convenience on platforms that lack lzip
1337 if you want to build the rearguard tarball. (Problem reported by
1340 tzdata.zi is now more stable from release to release. (Problem
1341 noted by Tom Lane.) It is also a bit shorter.
1343 tzdata.zi now can contain comment lines documenting configuration
1344 information, such as which data format was selected, which input
1345 files were used, and how leap seconds are treated. (Problems
1346 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1347 are used these comment lines are absent, for backward
1348 compatibility. A redistributor intending to alter its copy of the
1349 files should also append "-LABEL" to the 'version' file's first
1350 line, where "LABEL" identifies the redistributor's change.
1353 Release 2018e - 2018-05-01 23:42:51 -0700
1357 North Korea switches back to +09 on 2018-05-05.
1358 The main format uses negative DST again, for Ireland etc.
1359 'make tarballs' now also builds a rearguard tarball.
1360 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1362 Changes to past and future timestamps
1364 North Korea switches back from +0830 to +09 on 2018-05-05.
1365 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1368 Bring back the negative-DST changes of 2018a, except be more
1369 compatible with data parsers that do not support negative DST.
1370 Also, this now affects historical timestamps in Namibia and the
1371 former Czechoslovakia, not just Ireland. The main format now uses
1372 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1373 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1374 does not affect UT offsets, only time zone abbreviations and the
1375 tm_isdst flag. Also, this does not affect rearguard or vanguard
1376 formats; effectively the main format now uses vanguard instead of
1377 rearguard format. Data parsers that do not support negative DST
1378 can still use data from the rearguard tarball described below.
1380 Changes to build procedure
1382 The command 'make tarballs' now also builds the tarball
1383 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1384 except that it uses rearguard format intended for trailing-edge
1387 Changes to data format and to code
1389 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1390 suffix, which specifies whether the adjusted time is standard time
1391 or daylight saving time. If no suffix is given, daylight saving
1392 time is used if and only if the SAVE column is nonzero; this is
1393 the longstanding behavior. Although this new feature is not used
1394 in tzdata, it could be used to specify the legal time in Namibia
1395 1994-2017, as opposed to the popular time (see below).
1397 Changes to past timestamps
1399 From 1994 through 2017 Namibia observed DST in winter, not summer.
1400 That is, it used negative DST, as Ireland still does. This change
1401 does not affect UTC offsets; it affects only the tm_isdst flag and
1402 the abbreviation used during summer, which is now CAT, not WAST.
1403 Although (as noted by Michael Deckers) summer and winter time were
1404 both simply called "standard time" in Namibian law, in common
1405 practice winter time was considered to be DST (as noted by Stephen
1406 Colebourne). The full effect of this change is only in vanguard
1407 and main format; in rearguard format, the tm_isdst flag is still
1408 zero in winter and nonzero in summer.
1410 In 1946/7 Czechoslovakia also observed negative DST in winter.
1411 The full effect of this change is only in vanguard and main
1412 formats; in rearguard format, it is modeled as plain GMT without
1413 daylight saving. Also, the dates of some 1944/5 DST transitions
1414 in Czechoslovakia have been changed.
1417 Release 2018d - 2018-03-22 07:05:46 -0700
1421 Palestine starts DST a week earlier in 2018.
1422 Add support for vanguard and rearguard data consumers.
1423 Add subsecond precision to source data format, though not to data.
1425 Changes to future timestamps
1427 In 2018, Palestine starts DST on March 24, not March 31.
1428 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1430 Changes to past and future timestamps
1432 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1433 at 04:00. (Thanks to Steffen Thorsen.)
1435 Changes to past timestamps
1437 Historical transitions for Uruguay, represented by
1438 America/Montevideo, have been updated per official legal documents,
1439 replacing previous data mainly originating from the inventions of
1440 Shanks & Pottenger. This has resulted in adjustments ranging from
1441 30 to 90 minutes in either direction over at least two dozen
1442 distinct periods ranging from one day to several years in length.
1443 A mere handful of pre-1991 transitions are unaffected; data since
1444 then has come from more reliable contemporaneous reporting. These
1445 changes affect various timestamps in 1920-1923, 1936, 1939,
1446 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1447 Additionally, Uruguay's pre-standard-time UT offset has been
1448 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1449 match the location of the Observatory of the National Meteorological
1450 Institute in Montevideo.
1451 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1453 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1454 (Thanks to Kerry Shetline.)
1456 Fix the 1912-01-01 transition for Portugal and its colonies.
1457 This transition was at 00:00 according to the new UT offset, not
1458 according to the old one. Also assume that Cape Verde switched on
1459 the same date as the rest, not in 1907. This affects
1460 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1461 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1462 (Thanks to Michael Deckers.)
1464 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1467 Changes to past time zone abbreviations
1469 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1470 is no clock change associated with the transition.
1472 Changes to build procedure
1474 The new DATAFORM macro in the Makefile lets the installer choose
1475 among three source data formats. The idea is to lessen downstream
1476 disruption when data formats are improved.
1478 * DATAFORM=vanguard installs from the latest, bleeding-edge
1479 format. DATAFORM=main (the default) installs from the format
1480 used in the 'africa' etc. files. DATAFORM=rearguard installs
1481 from a trailing-edge format. Eventually, elements of today's
1482 vanguard format should move to the main format, and similarly
1483 the main format's features should eventually move to the
1486 * In the current version, the main and rearguard formats are
1487 identical and match that of 2018c, so this change does not
1488 affect default behavior. The vanguard format currently contains
1489 one feature not in the main format: negative SAVE values. This
1490 improves support for Ireland, which uses Irish Standard Time
1491 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1492 supported negative SAVE values for decades, and this feature
1493 should move to the main format soon. However, it will not move
1494 to the rearguard format for quite some time because some
1495 downstream parsers do not support it.
1497 * The build procedure constructs three files vanguard.zi, main.zi,
1498 and rearguard.zi, one for each format. Although the files
1499 represent essentially the same data, they may have minor
1500 discrepancies that users are not likely to notice. The files
1501 are intended for downstream data consumers and are not
1502 installed. Zoneinfo parsers that do not support negative SAVE values
1503 should start using rearguard.zi, so that they will be unaffected
1504 when the negative-DST feature moves from vanguard to main.
1505 Bleeding-edge Zoneinfo parsers that support the new features
1506 already can use vanguard.zi; in this respect, current tzcode is
1509 The Makefile should now be safe for parallelized builds, and 'make
1510 -j to2050new.tzs' is now much faster on a multiprocessor host
1513 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1514 prepends TZDIR/ to file names that do not begin with '/'. This is
1515 not recommended for general use, due to its security implications.
1516 (From a suggestion by Manuela Friedrich.)
1520 zic now accepts subsecond precision in expressions like
1521 00:19:32.13, which is approximately the legal time of the
1522 Netherlands from 1835 to 1937. However, because it is
1523 questionable whether the few recorded uses of non-integer offsets
1524 had subsecond precision in practice, there are no plans for tzdata
1525 to use this feature. (Thanks to Steve Allen for pointing out
1526 the limitations of historical data in this area.)
1528 The code is a bit more portable to MS-Windows. Installers can
1529 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1530 reserve identifiers like 'localtime'. (Thanks to Manuela
1533 Changes to documentation and commentary
1535 theory.html now outlines tzdb's extensions to POSIX's model for
1536 civil time, and has a section "POSIX features no longer needed"
1537 that lists POSIX API components that are now vestigial.
1538 (From suggestions by Steve Summit.) It also better distinguishes
1539 time zones from tz regions. (From a suggestion by Guy Harris.)
1541 Commentary is now more consistent about using the phrase "daylight
1542 saving time", to match the C name tm_isdst. Daylight saving time
1543 need not occur in summer, and need not have a positive offset from
1546 Commentary about historical transitions in Uruguay has been expanded
1547 with links to many relevant legal documents.
1548 (Thanks to Tim Parenti.)
1550 Commentary now uses some non-ASCII characters with Unicode value
1551 less than U+0100, as they can be useful and should work even with
1552 older editors such as XEmacs.
1555 Release 2018c - 2018-01-22 23:00:44 -0800
1558 Revert Irish changes that relied on negative SAVE values.
1562 Revert the 2018a change to Europe/Dublin. As before, this change
1563 does not affect UT offsets or abbreviations; it affects only
1564 whether timestamps are considered to be standard time or
1565 daylight-saving time, as expressed in the tm_isdst flag of C's
1566 struct tm type. This reversion is intended to be a temporary
1567 workaround for problems discovered with downstream uses of
1568 releases 2018a and 2018b, which implemented Irish time by using
1569 negative SAVE values in the Eire rules of the 'europe' file.
1570 Although negative SAVE values have been part of tzcode for many
1571 years and are supported by many platforms, they were not
1572 documented before 2018a and ICU and OpenJDK do not currently
1573 support them. A mechanism to export data to platforms lacking
1574 support for negative DST is planned to be developed before the
1575 change is reapplied. (Problems reported by Deborah Goldsmith and
1576 Stephen Colebourne.)
1578 Changes to past timestamps
1580 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1581 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1583 Changes to build procedure
1585 The build procedure now works around mawk 1.3.3's lack of support
1586 for character class expressions. (Problem reported by Ohyama.)
1589 Release 2018b - 2018-01-17 23:24:48 -0800
1592 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1594 Changes to build procedure
1596 The distribution now contains the file 'pacificnew' again.
1597 This file was inadvertently omitted in the 2018a distribution.
1598 (Problem reported by Matias Fonzo.)
1601 Release 2018a - 2018-01-12 22:29:21 -0800
1604 São Tomé and Príncipe switched from +00 to +01.
1605 Brazil's DST will now start on November's first Sunday.
1606 Ireland's standard time is now in the summer, not the winter.
1607 Use Debian-style installation locations, instead of 4.3BSD-style.
1610 Changes to past and future timestamps
1612 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1613 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1615 Changes to future timestamps
1617 Starting in 2018 southern Brazil will begin DST on November's
1618 first Sunday instead of October's third Sunday. (Thanks to
1621 Changes to past timestamps
1623 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1624 been corrected. The 'backzone' and 'zone.tab' files did not agree
1625 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1628 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1629 BST instead of BOST, to be more consistent with the convention
1630 used for Latvian Summer Time (1918-9) and for British Summer Time.
1634 Change Europe/Dublin so that it observes Irish Standard Time (UT
1635 +01) in summer and GMT (as negative daylight-saving) in winter,
1636 instead of observing standard time (GMT) in winter and Irish
1637 Summer Time (UT +01) in summer. This change does not affect UT
1638 offsets or abbreviations; it affects only whether timestamps are
1639 considered to be standard time or daylight-saving time, as
1640 expressed in the tm_isdst flag of C's struct tm type.
1641 (Discrepancy noted by Derick Rethans.)
1643 Changes to build procedure
1645 The default installation locations have been changed to mostly
1646 match Debian circa 2017, instead of being designed as an add-on to
1647 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1648 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1649 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1650 locations more precisely. (This responds to suggestions from
1651 Brian Inglis and from Steve Summit.)
1653 The default installation procedure no longer creates the
1654 backward-compatibility link US/Pacific-New, which causes
1655 confusion during user setup (e.g., see Debian bug 815200).
1656 Use 'make BACKWARD="backward pacificnew"' to create the link
1657 anyway, for now. Eventually we plan to remove the link entirely.
1659 tzdata.zi now contains a version-number comment.
1660 (Suggested by Tom Lane.)
1662 The Makefile now quotes values like BACKWARD more carefully when
1663 passing them to the shell. (Problem reported by Zefram.)
1665 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1666 that have snprintf and use pre-C99 compilers. (Problem reported
1671 zic has a new option -t FILE that specifies the location of the
1672 file that determines local time when TZ is unset. The default for
1673 this location can be configured via the new TZDEFAULT makefile
1674 macro, which defaults to /etc/localtime.
1676 Diagnostics and commentary now distinguish UT from UTC more
1677 carefully; see theory.html for more information about UT vs UTC.
1679 zic has been ported to GCC 8's -Wstringop-truncation option.
1680 (Problem reported by Martin Sebor.)
1682 Changes to documentation and commentary
1684 The zic man page now documents the longstanding behavior that
1685 times and years can be out of the usual range, with negative times
1686 counting backwards from midnight and with year 0 preceding year 1.
1687 (Problem reported by Michael Deckers.)
1689 The theory.html file now mentions the POSIX limit of six chars
1690 per abbreviation, and lists alphabetic abbreviations used.
1692 The files tz-art.htm and tz-link.htm have been renamed to
1693 tz-art.html and tz-link.html, respectively, for consistency with
1694 other file names and to simplify web server configuration.
1697 Release 2017c - 2017-10-20 14:49:34 -0700
1700 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1701 Fiji ends DST 2018-01-14, not 2018-01-21.
1702 Namibia switches from +01/+02 to +02 on 2018-04-01.
1703 Sudan switches from +03 to +02 on 2017-11-01.
1704 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1705 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1706 A new file tzdata.zi now holds a small text copy of all data.
1707 The zic input format has been regularized slightly.
1709 Changes to future timestamps
1711 Northern Cyprus has decided to resume EU rules starting
1712 2017-10-29, thus reinstituting winter time.
1714 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1715 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1718 Namibia will switch from +01 with DST to +02 all year on
1719 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1720 at 02:00. (Thanks to Steffen Thorsen.)
1722 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1723 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1724 Africa/Juba is no longer a link to Africa/Khartoum.
1726 Tonga has likely ended its experiment with DST, and will not
1727 adjust its clocks on 2017-11-05. Although Tonga has not announced
1728 whether it will continue to observe DST, the IATA is assuming that
1729 it will not. (Thanks to David Wade.)
1731 Turks & Caicos will switch from -04 all year to -05 with US DST on
1732 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1733 at 02:00. (Thanks to Steffen Thorsen.)
1735 Changes to past timestamps
1737 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1738 (Thanks to Arthur David Olson.)
1740 Detroit did not observe DST in 1967.
1742 Use railway time for Asia/Kolkata before 1941, by switching to
1743 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1744 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1746 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1747 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1749 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1750 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1752 Adjust the 1867 transition in Alaska to better reflect the
1753 historical record, by changing it to occur on 1867-10-18 at 15:30
1754 Sitka time rather than at the start of 1867-10-17 local time.
1755 Although strictly speaking this is accurate only for Sitka,
1756 the rest of Alaska's blanks need to be filled in somehow.
1758 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1759 (Thanks to Michael Deckers.)
1761 Add 7 s to the UT offset in Asia/Yangon before 1920.
1763 Changes to zone names
1765 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1766 exceeded the 14-character limit and was an unused misnomer anyway.
1768 Changes to build procedure
1770 To support applications that prefer to read time zone data in text
1771 form, two zic input files tzdata.zi and leapseconds are now
1772 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1773 leapseconds tzdata.zi' can reproduce the tzdata binary files
1774 without and with leap seconds, respectively. To prevent these two
1775 new files from being installed, use 'make TZDATA_TEXT=', and to
1776 suppress leap seconds from the tzdata text installation, use 'make
1777 TZDATA_TEXT=tzdata.zi'.
1779 'make BACKWARD=' now suppresses backward-compatibility names
1780 like 'US/Pacific' that are defined in the 'backward' and
1783 'make check' now works on systems that lack a UTF-8 locale,
1784 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1785 the name of a UTF-8 locale, if you have one.
1787 Y2K runtime checks are no longer enabled by default. Add
1788 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1789 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1790 to disable them. (New name suggested by Brian Inglis.)
1792 The build procedure for zdump now works on AIX 7.1.
1793 (Problem reported by Kees Dekker.)
1797 zic and the reference runtime now reject multiple leap seconds
1798 within 28 days of each other, or leap seconds before the Epoch.
1799 As a result, support for double leap seconds, which was
1800 obsolescent and undocumented, has been removed. Double leap
1801 seconds were an error in the C89 standard; they have never existed
1802 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
1803 noticing glitches in the code that uncovered this problem.)
1805 zic now warns about use of the obsolescent and undocumented -y
1806 option, and about use of the obsolescent TYPE field of Rule lines.
1808 zic now allows unambiguous abbreviations like "Sa" and "Su" for
1809 weekdays; formerly it rejected them due to a bug. Conversely, zic
1810 no longer considers non-prefixes to be abbreviations; for example,
1811 it no longer accepts "lF" as an abbreviation for "lastFriday".
1812 Also, zic warns about the undocumented usage with a "last-"
1813 prefix, e.g., "last-Fri".
1815 Similarly, zic now accepts the unambiguous abbreviation "L" for
1816 "Link" in ordinary context and for "Leap" in leap-second context.
1817 Conversely, zic no longer accepts non-prefixes such as "La" as
1818 abbreviations for words like "Leap".
1820 zic no longer accepts leap second lines in ordinary input, or
1821 ordinary lines in leap second input. Formerly, zic sometimes
1822 warned about this undocumented usage and handled it incorrectly.
1824 The new macro HAVE_TZNAME governs whether the tzname external
1825 variable is exported, instead of USG_COMPAT. USG_COMPAT now
1826 governs only the external variables "timezone" and "daylight".
1827 This change is needed because the three variables are not in the
1828 same category: although POSIX requires tzname, it specifies the
1829 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
1830 if not defined, the code attempts to guess it from other macros.
1832 localtime.c and difftime.c no longer require stdio.h, and .c files
1833 other than zic.c no longer require sys/wait.h.
1835 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
1837 Calculation of time_t extrema works around a bug in GCC 4.8.4
1838 (Reported by Stan Shebs and Joseph Myers.)
1840 zic.c no longer mistranslates formats of line numbers in non-English
1841 locales. (Problem reported by Benno Schulenberg.)
1843 Several minor changes have been made to the code to make it a
1844 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
1845 Dekker for reporting the problems.)
1847 Changes to documentation and commentary
1849 The two new files 'theory.html' and 'calendars' contain the
1850 contents of the removed file 'Theory'. The goal is to document
1851 tzdb theory more accessibly.
1853 The zic man page now documents abbreviation rules.
1855 tz-link.htm now covers how to apply tzdata changes to clients.
1856 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
1858 The leap-seconds.list URL has been updated to something that is
1859 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
1861 Release 2017b - 2017-03-17 07:30:38 -0700
1863 Briefly: Haiti has resumed DST.
1865 Changes to past and future timestamps
1867 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
1869 Changes to past timestamps
1871 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
1873 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
1874 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
1878 The reference localtime implementation now falls back on the
1879 current US daylight-saving transition rules rather than the
1880 1987-2006 rules. This fallback occurs only when (1) the TZ
1881 environment variable has a value like "AST4ADT" that asks
1882 for daylight saving time but does not specify the rules, (2) there
1883 is no file by that name, and (3) the TZDEFRULES file cannot be
1884 loaded. (Thanks to Tom Lane.)
1887 Release 2017a - 2017-02-28 00:05:36 -0800
1889 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
1892 Changes to future timestamps
1894 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
1896 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
1897 Its clocks diverge from America/Santiago starting 2017-05-13 at
1898 23:00, hiving off a new zone America/Punta_Arenas. Although the
1899 Chilean government says this change expires in May 2019, for now
1900 assume it's permanent. (Thanks to Juan Correa and Deborah
1901 Goldsmith.) This also affects Antarctica/Palmer.
1903 Changes to past timestamps
1905 Fix many entries for historical timestamps for Europe/Madrid
1906 before 1979, to agree with tables compiled by Pere Planesas of the
1907 National Astronomical Observatory of Spain. As a side effect,
1908 this changes some timestamps for Africa/Ceuta before 1929, which
1909 are probably guesswork anyway. (Thanks to Steve Allen and
1910 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
1911 correcting the 1901 transition.)
1913 Ecuador observed DST from 1992-11-28 to 1993-02-05.
1914 (Thanks to Alois Treindl.)
1916 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
1917 (Thanks to Stepan Golosunov.)
1919 Changes to past and future time zone abbreviations
1921 Switch to numeric time zone abbreviations for South America, as
1922 part of the ongoing project of removing invented abbreviations.
1923 This avoids the need to invent an abbreviation for the new Chilean
1924 new zone. Similarly, switch from invented to numeric time zone
1925 abbreviations for Afghanistan, American Samoa, the Azores,
1926 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
1927 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
1928 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
1929 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
1930 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
1931 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
1932 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
1933 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
1934 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
1935 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
1936 for half-hour daylight saving time in Belize before 1944 and in
1937 the Dominican Republic before 1975; and for Canary Islands before
1938 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
1939 Indian Summer Time before 1942, for Indonesia before around 1964,
1940 for Kenya before 1960, for Liberia before 1973, for Madeira before
1941 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
1942 Pakistan before 1971, for Western Sahara before 1977, and for
1943 Zaporozhye in 1880-1924.
1945 For Alaska time from 1900 through 1967, instead of "CAT" use the
1946 abbreviation "AST", the abbreviation commonly used at the time
1947 (Atlantic Standard Time had not been standardized yet). Use "AWT"
1948 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
1950 Use "CST" and "CDT" instead of invented abbreviations for Macau
1951 before 1999 and Taiwan before 1938, and use "JST" instead of the
1952 invented abbreviation "JCST" for Japan and Korea before 1938.
1954 Change to database entry category
1956 Move the Pacific/Johnston link from 'australasia' to 'backward',
1957 since Johnston is now uninhabited.
1961 zic no longer mishandles some transitions in January 2038 when it
1962 attempts to work around Qt bug 53071. This fixes a bug affecting
1963 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
1964 now contains a workaround, useful when loading a file generated by
1965 a buggy zic. (Problem and localtime.c fix reported by Bradley
1968 zdump -i now outputs non-hour numeric time zone abbreviations
1969 without a colon, e.g., "+0530" rather than "+05:30". This agrees
1970 with zic %z and with common practice, and simplifies auditing of
1973 zdump is now buildable again with -DUSE_LTZ=0.
1974 (Problem reported by Joseph Myers.)
1976 zdump.c now always includes private.h, to avoid code duplication
1977 with private.h. (Problem reported by Kees Dekker.)
1979 localtime.c no longer mishandles early or late timestamps
1980 when TZ is set to a POSIX-style string that specifies DST.
1981 (Problem reported by Kees Dekker.)
1983 date and strftime now cause %z to generate "-0000" instead of
1984 "+0000" when the UT offset is zero and the time zone abbreviation
1987 Changes to documentation and commentary
1989 The 'Theory' file now better documents choice of historical time
1990 zone abbreviations. (Problems reported by Michael Deckers.)
1992 tz-link.htm now covers leap smearing, which is popular in clouds.
1995 Release 2016j - 2016-11-22 23:17:13 -0800
1997 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
1999 Changes to future timestamps
2001 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
2002 This hives off a new zone Europe/Saratov from Europe/Volgograd.
2003 (Thanks to Yuri Konotopov and Stepan Golosunov.)
2005 Changes to past timestamps
2007 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
2008 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
2009 1999, not fall 1994. (Thanks to Stepan Golosunov.)
2011 Changes to past time zone abbreviations
2013 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
2014 summer time before 1948. The old use of "EET" was a typo.
2018 zic no longer mishandles file systems that lack hard links, fixing
2019 bugs introduced in 2016g. (Problems reported by Tom Lane.)
2020 Also, when the destination already contains symbolic links, zic
2021 should now work better on systems where the 'link' system call
2022 does not follow symbolic links.
2024 Changes to documentation and commentary
2026 tz-link.htm now documents the relationship between release version
2027 numbers and development-repository commit tags. (Suggested by
2030 The 'Theory' file now documents UT.
2032 iso3166.tab now accents "Curaçao", and commentary now mentions
2033 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
2036 Release 2016i - 2016-11-01 23:19:52 -0700
2038 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
2039 reintroduces DST on 2016-11-06.
2041 Changes to future timestamps
2043 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
2044 2017-01-15 at 03:00. Assume future observances in Tonga will be
2045 from the first Sunday in November through the third Sunday in
2046 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
2047 time zone abbreviations for this zone.
2049 Changes to past and future timestamps
2051 Northern Cyprus is now +03 year round, causing a split in Cyprus
2052 time zones starting 2016-10-30 at 04:00. This creates a zone
2053 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
2055 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
2056 (Thanks to Steffen Thorsen.)
2058 Changes to past timestamps
2060 Several corrections were made for pre-1975 timestamps in Italy.
2061 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
2064 First, the 1893-11-01 00:00 transition in Italy used the new UT
2065 offset (+01), not the old (+00:49:56). (Thanks to Michael
2068 Second, rules for daylight saving in Italy were changed to agree
2069 with Italy's National Institute of Metrological Research (INRiM)
2070 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
2071 Inglis, and Michael Deckers):
2073 The 1916-06-03 transition was at 24:00, not 00:00.
2075 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
2078 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
2081 The 1944-09-17 transition was at 03:00, not 01:00. This
2082 particular change is taken from Italian law as INRiM's table,
2083 (which says 02:00) appears to have a typo here. Also, keep the
2084 1944-04-03 transition for Europe/Rome, as Rome was controlled by
2087 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
2092 The code should now be buildable on AmigaOS merely by setting the
2093 appropriate Makefile variables. (From a patch by Carsten Larsen.)
2096 Release 2016h - 2016-10-19 23:17:57 -0700
2098 Changes to future timestamps
2100 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2101 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
2102 future fall transitions will be on the last Saturday of October
2103 at 01:00, which is consistent with predicted spring transitions
2104 on the last Saturday of March. (Thanks to Tim Parenti.)
2106 Changes to past timestamps
2108 In Turkey, transitions in 1986-1990 were at 01:00 standard time
2109 not at 02:00, and the spring 1994 transition was on March 20, not
2110 March 27. (Thanks to Kıvanç Yazan.)
2112 Changes to past and future time zone abbreviations
2114 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
2115 instead of alphabetic ones like "IST" and "LKT". Various
2116 English-language sources use "IST", "LKT" and "SLST", with no
2117 working consensus. (Usage of "SLST" mentioned by Sadika
2122 zic no longer mishandles relativizing file names when creating
2123 symbolic links like /etc/localtime, when these symbolic links
2124 are outside the usual directory hierarchy. This fixes a bug
2125 introduced in 2016g. (Problem reported by Andreas Stieger.)
2127 Changes to build procedure
2129 New rules 'traditional_tarballs' and 'traditional_signatures' for
2130 building just the traditional-format distribution. (Requested by
2133 The file 'version' is now put into the tzdata tarball too.
2134 (Requested by Howard Hinnant.)
2136 Changes to documentation and commentary
2138 The 'Theory' file now has a section on interface stability.
2139 (Requested by Paul Koning.) It also mentions features like
2140 tm_zone and localtime_rz that have long been supported by the
2143 tz-link.htm has improved coverage of time zone boundaries suitable
2144 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
2147 The US commentary now mentions Allen and the "day of two noons".
2149 The Fiji commentary mentions the government's 2016-10-03 press
2150 release. (Thanks to Raymond Kumar.)
2153 Release 2016g - 2016-09-13 08:56:38 -0700
2155 Changes to future timestamps
2157 Turkey switched from EET/EEST (+02/+03) to permanent +03,
2158 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
2159 than an invented abbreviation for the new time.
2161 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
2162 (Thanks to Tim Parenti.)
2164 Changes to past timestamps
2166 For America/Los_Angeles, spring-forward transition times have been
2167 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2170 For zones using Soviet time on 1919-07-01, transitions to UT-based
2171 time were at 00:00 UT, not at 02:00 local time. The affected
2172 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2173 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2175 Changes to past and future time zone abbreviations
2177 The Factory zone now uses the time zone abbreviation -00 instead
2178 of a long English-language string, as -00 is now the normal way to
2179 represent an undefined time zone.
2181 Several zones in Antarctica and the former Soviet Union, along
2182 with zones intended for ships at sea that cannot use POSIX TZ
2183 strings, now use numeric time zone abbreviations instead of
2184 invented or obsolete alphanumeric abbreviations. The affected
2185 zones are Antarctica/Casey, Antarctica/Davis,
2186 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2187 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2188 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2189 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2190 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2191 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2192 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2193 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2194 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2195 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2196 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2197 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2198 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2199 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2200 was replaced by +05, whereas MSK and MSD were kept as they are not
2201 our invention and are widely used.
2203 Changes to zone names
2205 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2206 (Thanks to David Massoud.)
2210 zic no longer generates binary files containing POSIX TZ-like
2211 strings that disagree with the local time type after the last
2212 explicit transition in the data. This fixes a bug with
2213 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2214 on the reference platform. (Thanks to Alexander Belopolsky for
2215 reporting the bug and suggesting a way forward.)
2217 If the installed localtime and/or posixrules files are symbolic
2218 links, zic now keeps them symbolic links when updating them, for
2219 compatibility with platforms like OpenSUSE where other programs
2220 configure these files as symlinks.
2222 zic now avoids hard linking to symbolic links, avoids some
2223 unnecessary mkdir and stat system calls, and uses shorter file
2226 zdump has a new -i option to generate transitions in a
2227 more-compact but still human-readable format. This option is
2228 experimental, and the output format may change in future versions.
2229 (Thanks to Jon Skeet for suggesting that an option was needed,
2230 and thanks to Tim Parenti and Chris Rovick for further comments.)
2232 Changes to build procedure
2234 An experimental distribution format is available, in addition
2235 to the traditional format which will continue to be distributed.
2236 The new format is a tarball tzdb-VERSION.tar.lz with signature
2237 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2238 tzdb-VERSION containing the code and data of the traditional
2239 two-tarball format, along with extra data that may be useful.
2240 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2241 for comments about the experimental format.)
2243 The release version number is now more accurate in the usual case
2244 where releases are built from a Git repository. For example, if
2245 23 commits and some working-file changes have been made since
2246 release 2016g, the version number is now something like
2247 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2248 Tagged releases use the same version number format as before,
2249 e.g., '2016g'. To support the more-accurate version number, its
2250 specification has moved from a line in the Makefile to a new
2251 source file 'version'.
2253 The experimental distribution contains a file to2050.tzs that
2254 contains what should be the output of 'zdump -i -c 2050' on
2255 primary zones. If this file is available, 'make check' now checks
2256 that zdump generates this output.
2258 'make check_web' now works on Fedora-like distributions.
2260 Changes to documentation and commentary
2262 tzfile.5 now documents the new restriction on POSIX TZ-like
2263 strings that is now implemented by zic.
2265 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2266 (Thanks to Alexander Belopolsky.)
2268 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2269 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2270 description of Java 8 has been brought up to date (thanks to
2271 Stephen Colebourne). Its description of local time on Mars has
2272 been updated to match current practice, and URLs have been updated
2273 and some obsolete ones removed.
2276 Release 2016f - 2016-07-05 16:26:51 +0200
2278 Changes affecting future timestamps
2280 The Egyptian government changed its mind on short notice, and
2281 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2282 (Thanks to Mina Samuel.)
2284 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2285 (Thanks to Stepan Golosunov.)
2287 Changes to past and future timestamps
2289 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2290 abbreviations instead of invented ones.
2292 Changes affecting past timestamps
2294 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2295 (Thanks to Stepan Golosunov.)
2298 Release 2016e - 2016-06-14 08:46:16 -0700
2300 Changes affecting future timestamps
2302 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2303 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2304 For future years, guess April's last Thursday to October's last
2305 Thursday except for Ramadan.
2307 Changes affecting past timestamps
2309 Locations while uninhabited now use '-00', not 'zzz', as a
2310 placeholder time zone abbreviation. This is inspired by Internet
2311 RFC 3339 and is more consistent with numeric time zone
2312 abbreviations already used elsewhere. The change affects several
2313 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2314 1920 and Antarctica/Troll before 2005.
2316 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2317 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2321 zic now outputs a dummy transition at time 2**31 - 1 in zones
2322 whose POSIX-style TZ strings contain a '<'. This mostly works
2323 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2324 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2326 Changes affecting documentation and commentary
2328 tz-link.htm says why governments should give plenty of notice for
2329 time zone or DST changes, and refers to Matt Johnson's blog post.
2331 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2334 Release 2016d - 2016-04-17 22:50:29 -0700
2336 Changes affecting future timestamps
2338 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2339 (Thanks to Alexander Krivenyshev for the heads-up.)
2341 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2342 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2344 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2345 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2346 at 02:00. (Thanks to Stepan Golosunov.)
2348 Changes affecting past timestamps
2350 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2351 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2352 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2353 the same change. (Thanks to Stepan Golosunov.)
2355 Russia and nearby locations had daylight-saving transitions on
2356 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2357 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2360 Many corrections to historical time in Kazakhstan from 1991
2361 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2362 invented time zone abbreviations with numeric abbreviations.
2364 Changes to commentary
2366 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2369 Release 2016c - 2016-03-23 00:51:27 -0700
2371 Changes affecting future timestamps
2373 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2375 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2376 Correa for the heads-up, and to Tim Parenti for corrections.)
2377 Guess that future transitions are August's and May's second
2378 Saturdays at 24:00 mainland time. Also, call the period from
2379 2014-09-07 through 2016-05-14 daylight saving time instead of
2380 standard time, as that seems more appropriate now.
2382 Changes affecting past timestamps
2384 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2385 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2386 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2387 (Thanks to Stepan Golosunov.)
2389 Changes to commentary
2391 Several updates and URLs for historical and proposed Russian changes.
2392 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2395 Release 2016b - 2016-03-12 17:30:14 -0800
2399 Starting with release 2016b, some data entries cause zic implementations
2400 derived from tz releases 2005j through 2015e to issue warnings like
2401 "time zone abbreviation differs from POSIX standard (+03)".
2402 These warnings should not otherwise affect zic's output and can safely be
2403 ignored on today's platforms, as the warnings refer to a restriction in
2404 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2405 warnings is to upgrade to zic derived from tz releases 2015f and later.
2407 Changes affecting future timestamps
2409 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2410 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2411 2016-03-27 at 02:00 local time. They need distinct zones since their
2412 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2413 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2414 and local time. The Astrakhan change is already official; the others have
2415 passed the first reading in the State Duma and are extremely likely.
2416 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2417 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2418 and Stepan Golosunov for followup.)
2420 As a trial of a new system that needs less information to be made up,
2421 the new zones use numeric time zone abbreviations like "+04"
2422 instead of invented abbreviations like "ASTT".
2424 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2427 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2428 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2429 Saturday at 01:00, not March's last Friday at 24:00.
2431 Changes affecting past timestamps
2433 Europe/Chisinau observed DST during 1990, and switched from +04 to
2434 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2435 (Thanks to Stepan Golosunov.)
2437 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2438 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2442 tzselect's diagnostics and checking, and checktab.awk's checking,
2443 have been improved. (Thanks to J William Piggott.)
2445 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2447 tzselect now tests Julian-date TZ settings more accurately.
2448 (Thanks to J William Piggott.)
2450 Changes to commentary
2452 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2454 tzselect again limits its menu comments so that menus fit on a
2455 24×80 alphanumeric display.
2457 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2459 In the Theory file, the description of possible time zone abbreviations in
2460 tzdata has been cleaned up, as the old description was unclear and
2461 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2464 Release 2016a - 2016-01-26 23:28:02 -0800
2466 Changes affecting future timestamps
2468 America/Cayman will not observe daylight saving this year after all.
2469 Revert our guess that it would. (Thanks to Matt Johnson.)
2471 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2472 (Thanks to Alexander Krivenyshev.)
2474 Asia/Tehran now has DST predictions for the year 2038 and later,
2475 to be March 21 00:00 to September 21 00:00. This is likely better
2476 than predicting no DST, albeit off by a day every now and then.
2478 Changes affecting past and future timestamps
2480 America/Metlakatla switched from PST all year to AKST/AKDT on
2481 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2483 America/Santa_Isabel has been removed, and replaced with a
2484 backward compatibility link to America/Tijuana. Its contents were
2485 apparently based on a misreading of Mexican legislation.
2487 Changes affecting past timestamps
2489 Asia/Karachi's two transition times in 2002 were off by a minute.
2490 (Thanks to Matt Johnson.)
2492 Changes affecting build procedure
2494 An installer can now combine leap seconds with use of the backzone file,
2495 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2496 The old 'make posix_packrat' rule is now marked as obsolescent.
2497 (Thanks to Ian Abbott for an initial implementation.)
2499 Changes affecting documentation and commentary
2501 A new file LICENSE makes it easier to see that the code and data
2502 are mostly public-domain. (Thanks to James Knight.) The three
2503 non-public-domain files now use the current (3-clause) BSD license
2504 instead of older versions of that license.
2506 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2507 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2508 on editing tz source files (with a mention of Sublime zoneinfo,
2509 thanks to Gilmore Davidson).
2511 The Theory and asia files now mention the 2015 book "The Global
2512 Transformation of Time, 1870-1950", and cite a couple of reviews.
2514 The America/Chicago entry now documents the informal use of US
2515 central time in Fort Pierre, South Dakota. (Thanks to Rick
2516 McDermid, Matt Johnson, and Steve Jones.)
2519 Release 2015g - 2015-10-01 00:39:51 -0700
2521 Changes affecting future timestamps
2523 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2526 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2527 (Thanks to Alexander Krivenyshev.)
2529 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2530 (Thanks to Ken Rylander.)
2532 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2533 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2534 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2536 Changes affecting past timestamps
2538 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2540 Changes affecting code
2542 localtime no longer mishandles America/Anchorage after 2037.
2543 (Thanks to Bradley White for reporting the bug.)
2545 On hosts with signed 32-bit time_t, localtime no longer mishandles
2546 Pacific/Fiji after 2038-01-16 14:00 UTC.
2548 The localtime module allows the variables 'timezone', 'daylight',
2549 and 'altzone' to be in common storage shared with other modules,
2550 and declares them in case the system <time.h> does not.
2551 (Problems reported by Kees Dekker.)
2553 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2554 This simplifies the code and is consistent with zdump.c.
2555 (Problem reported by Christos Zoulas.)
2557 Changes affecting documentation
2559 The tzfile man page now documents that transition times denote the
2560 starts (not the ends) of the corresponding time periods.
2561 (Ambiguity reported by Bill Seymour.)
2564 Release 2015f - 2015-08-10 18:06:56 -0700
2566 Changes affecting future timestamps
2568 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2569 The abbreviation remains "KST". (Thanks to Robert Elz.)
2571 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2574 Changes affecting past and future timestamps
2576 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2577 (Thanks to Roman Tudos.)
2579 Changes affecting data format and code
2581 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2582 field of a Rule line should now be '-'; the old values 'even',
2583 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2584 Although the implementation has not changed, these features do not
2585 work in the default installation, they are not used in the data,
2586 and they are now considered obsolescent.
2588 zic now checks that two rules don't take effect at the same time.
2589 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2590 simultaneity are now documented.
2592 The two characters '%z' in a zone format now stand for the UT
2593 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2594 five hours and thirty minutes ahead. This better supports time
2595 zone abbreviations conforming to POSIX.1-2001 and later.
2597 Changes affecting installed data files
2599 Comments for America/Halifax and America/Glace_Bay have been improved.
2600 (Thanks to Brian Inglis.)
2602 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2603 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2604 installed data files for Europe/Simferopol and Europe/Tallinn.
2605 It does not affect timestamps. (Thanks to Howard Hinnant.)
2607 Changes affecting code
2609 zdump and zic no longer warn about valid time zone abbreviations
2612 Some Visual Studio 2013 warnings have been suppressed.
2613 (Thanks to Kees Dekker.)
2615 'date' no longer sets the time of day and its -a, -d, -n and -t
2616 options have been removed. Long obsolescent, the implementation
2617 of these features had porting problems. Builders no longer need
2618 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2619 (Thanks to Kees Dekker for pointing out the problem.)
2621 Changes affecting documentation
2623 The Theory file mentions naming issues earlier, as these seem to be
2624 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2626 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2628 Mention that Herbert Samuel introduced the term "Summer Time".
2631 Release 2015e - 2015-06-13 10:56:02 -0700
2633 Changes affecting future timestamps
2635 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2636 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2638 Assume Cayman Islands will observe DST starting next year, using US rules.
2639 Although it isn't guaranteed, it is the most likely.
2641 Changes affecting data format
2643 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2644 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2646 Changes affecting code
2648 When displaying data, tzselect converts it to the current locale's
2649 encoding if the iconv command works. (Problem reported by random832.)
2651 tzselect no longer mishandles Dominica, fixing a bug introduced
2652 in Release 2014f. (Problem reported by Owen Leibman.)
2654 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2655 This fixes a bug introduced in Release 2014f.
2656 (Problem reported by Leonardo Chiquitto.)
2659 Release 2015d - 2015-04-24 08:09:46 -0700
2661 Changes affecting future timestamps
2663 Egypt will not observe DST in 2015 and will consider canceling it
2664 permanently. For now, assume no DST indefinitely.
2665 (Thanks to Ahmed Nazmy and Tim Parenti.)
2667 Changes affecting past timestamps
2669 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2670 1966-07-01. Also, Yukon's time zone history is documented better.
2671 (Thanks to Brian Inglis and Dennis Ferguson.)
2673 Change affecting past and future time zone abbreviations
2675 The abbreviations for Hawaii-Aleutian standard and daylight times
2676 have been changed from HAST/HADT to HST/HDT, as per US Government
2677 Printing Office style. This affects only America/Adak since 1983,
2678 as America/Honolulu was already using the new style.
2680 Changes affecting code
2682 zic has some minor performance improvements.
2685 Release 2015c - 2015-04-11 08:55:55 -0700
2687 Changes affecting future timestamps
2689 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2690 not 00:00 on April's last Friday. 2015's transition will therefore be on
2691 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2692 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2694 Changes affecting past timestamps
2696 The following changes affect some pre-1991 Chile-related timestamps
2697 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2699 The 1910 transition was January 10, not January 1.
2701 The 1918 transition was September 10, not September 1.
2703 The UT -04 time observed from 1932 to 1942 is now considered to
2704 be standard time, not year-round DST.
2706 Santiago observed DST (UT -03) from 1946-07-15 through
2707 1946-08-31, then reverted to standard time, then switched to -05
2710 Assume transitions before 1968 were at 00:00, since we have no data
2713 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2714 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2716 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2717 and omit all transitions on Pacific/Easter from 1942 through 1946
2718 since we have no data suggesting that they existed.
2720 One more zone has been turned into a link, as it differed
2721 from an existing zone only for older timestamps. As usual,
2722 this change affects UT offsets in pre-1970 timestamps only.
2723 The zone's old contents have been moved to the 'backzone' file.
2724 The affected zone is America/Montreal.
2726 Changes affecting commentary
2728 Mention the TZUpdater tool.
2730 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2733 Release 2015b - 2015-03-19 23:28:11 -0700
2735 Changes affecting future timestamps
2737 Mongolia will start observing DST again this year, from the last
2738 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2739 (Thanks to Ganbold Tsagaankhuu.)
2741 Palestine will start DST on March 28, not March 27. Also,
2742 correct the fall 2014 transition from September 26 to October 24.
2743 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2745 Changes affecting past timestamps
2747 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2748 regression. (Thanks to Stuart Bishop for reporting the problem.)
2750 Some more zones have been turned into links, when they differed
2751 from existing zones only for older timestamps. As usual,
2752 these changes affect UT offsets in pre-1970 timestamps only.
2753 Their old contents have been moved to the 'backzone' file.
2754 The affected zones are: America/Antigua, America/Cayman,
2755 Pacific/Midway, and Pacific/Saipan.
2757 Changes affecting time zone abbreviations
2759 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2762 Changes affecting code
2764 Fix integer overflow bug in reference 'mktime' implementation.
2765 (Problem reported by Jörg Richter.)
2767 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2768 to be used in the same executable as standard-library time_t functions.
2769 (Problems reported by Bradley White.)
2771 Changes affecting commentary
2773 Cite the recent Mexican decree changing Quintana Roo's time zone.
2774 (Thanks to Carlos Raúl Perasso.)
2776 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2778 Update info about Mars time.
2781 Release 2015a - 2015-01-29 22:35:20 -0800
2783 Changes affecting future timestamps
2785 The Mexican state of Quintana Roo, represented by America/Cancun,
2786 will shift from Central Time with DST to Eastern Time without DST
2787 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2789 Chile will not change clocks in April or thereafter; its new standard time
2790 will be its old daylight saving time. This affects America/Santiago,
2791 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2793 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2794 (Thanks to Tim Parenti.)
2796 Changes affecting past timestamps
2798 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2799 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2800 Shanks about time in Iceland between 1837 and 1908.
2802 Some more zones have been turned into links, when they differed
2803 from existing zones only for older timestamps. As usual,
2804 these changes affect UT offsets in pre-1970 timestamps only.
2805 Their old contents have been moved to the 'backzone' file.
2806 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
2809 Changes affecting code
2811 tzalloc now scrubs time zone abbreviations compatibly with the way
2812 that tzset always has, by replacing invalid bytes with '_' and by
2813 shortening too-long abbreviations.
2815 tzselect ports to POSIX awk implementations, no longer mishandles
2816 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
2817 settings to the user. (Thanks to Stefan Kuhn.)
2819 Changes affecting build procedure
2821 'make check' now checks for links to links in the data.
2822 One such link (for Africa/Asmera) has been fixed.
2823 (Thanks to Stephen Colebourne for pointing out the problem.)
2825 Changes affecting commentary
2827 The leapseconds file commentary now mentions the expiration date.
2828 (Problem reported by Martin Burnicki.)
2830 Update Mexican Library of Congress URL.
2833 Release 2014j - 2014-11-10 17:37:11 -0800
2835 Changes affecting current and future timestamps
2837 Turks & Caicos' switch from US eastern time to UT -04 year-round
2838 did not occur on 2014-11-02 at 02:00. It's currently scheduled
2839 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
2841 Changes affecting past timestamps
2843 Many pre-1989 timestamps have been corrected for Asia/Seoul and
2844 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
2845 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
2846 longer guess that Pyongyang mimicked Seoul time after World War II,
2847 as this is politically implausible.
2849 Some more zones have been turned into links, when they differed
2850 from existing zones only for older timestamps. As usual,
2851 these changes affect UT offsets in pre-1970 timestamps only.
2852 Their old contents have been moved to the 'backzone' file.
2853 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
2854 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
2855 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
2858 Changes affecting commentary
2860 The commentary is less enthusiastic about Shanks as a source,
2861 and is more careful to distinguish UT from UTC.
2864 Release 2014i - 2014-10-21 22:04:57 -0700
2866 Changes affecting future timestamps
2868 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
2869 (Thanks to Ken Rylander for the heads-up.) Guess that future
2870 years will use a similar pattern.
2872 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
2873 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
2874 (Thanks to Kiley Walbom for the heads-up.)
2876 Changes affecting time zone abbreviations
2878 Since Belarus is not changing its clocks even though Moscow is,
2879 the time zone abbreviation in Europe/Minsk is changing from FET
2880 to its more-traditional value MSK on 2014-10-26 at 01:00.
2881 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
2883 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
2884 Indochina, to distinguish it better from ICT (+07).
2886 Changes affecting past timestamps
2888 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
2889 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
2890 authoritative book). Asia/Ho_Chi_Minh has been added to
2891 zone1970.tab, to give tzselect users in Vietnam two choices,
2892 since north and south Vietnam disagreed after our 1970 cutoff.
2894 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
2895 they differed from existing zones only for older timestamps. As
2896 usual, these changes affect pre-1970 timestamps only. Their old
2897 contents have been moved to the 'backzone' file.
2899 Changes affecting code
2901 The time-related library functions now set errno on failure, and
2902 some crashes in the new tzalloc-related library functions have
2903 been fixed. (Thanks to Christos Zoulas for reporting most of
2904 these problems and for suggesting fixes.)
2906 If USG_COMPAT is defined and the requested timestamp is standard time,
2907 the tz library's localtime and mktime functions now set the extern
2908 variable timezone to a value appropriate for that timestamp; and
2909 similarly for ALTZONE, daylight saving time, and the altzone variable.
2910 This change is a companion to the tzname change in 2014h, and is
2911 designed to make timezone and altzone more compatible with tzname.
2913 The tz library's functions now set errno to EOVERFLOW if they fail
2914 because the result cannot be represented. ctime and ctime_r now
2915 return NULL and set errno when a timestamp is out of range, rather
2916 than having undefined behavior.
2918 Some bugs associated with the new 2014g functions have been fixed.
2919 This includes a bug that largely incapacitated the new functions
2920 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
2921 It also includes some uses of uninitialized variables after tzalloc.
2922 The new code uses the standard type 'ssize_t', which the Makefile
2923 now gives porting advice about.
2925 Changes affecting commentary
2927 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
2930 Release 2014h - 2014-09-25 18:59:03 -0700
2932 Changes affecting past timestamps
2934 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
2936 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
2937 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
2939 Some more zones have been turned into links, when they differed
2940 from existing zones only for older timestamps. As usual,
2941 these changes affect UT offsets in pre-1970 timestamps only.
2942 Their old contents have been moved to the 'backzone' file.
2943 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
2944 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
2945 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
2947 Changes affecting code
2949 zdump -V and -v now output gmtoff= values on all platforms,
2950 not merely on platforms defining TM_GMTOFF.
2952 The tz library's localtime and mktime functions now set tzname to a value
2953 appropriate for the requested timestamp, and zdump now uses this
2954 on platforms not defining TM_ZONE, fixing a 2014g regression.
2955 (Thanks to Tim Parenti for reporting the problem.)
2957 The tz library no longer sets tzname if localtime or mktime fails.
2959 zdump -c no longer mishandles transitions near year boundaries.
2960 (Thanks to Tim Parenti for reporting the problem.)
2962 An access to uninitialized data has been fixed.
2963 (Thanks to Jörg Richter for reporting the problem.)
2965 When THREAD_SAFE is defined, the code ports to the C11 memory model.
2966 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
2967 and two threads race to initialize data used by gmtime-like functions.
2968 (Thanks to Andy Heninger for reporting the problems.)
2970 Changes affecting build procedure
2972 'make check' now checks better for properly-sorted data.
2974 Changes affecting documentation and commentary
2976 zdump's gmtoff=N output is now documented, and its isdst=D output
2977 is now documented to possibly output D values other than 0 or 1.
2979 zdump -c's treatment of years is now documented to use the
2980 Gregorian calendar and Universal Time without leap seconds,
2981 and its behavior at cutoff boundaries is now documented better.
2982 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
2984 Programs are now documented to use the proleptic Gregorian calendar.
2985 (Thanks to Alan Barrett for the suggestion.)
2987 Fractional-second GMT offsets have been documented for civil time
2988 in 19th-century Chennai, Jakarta, and New York.
2991 Release 2014g - 2014-08-28 12:31:23 -0700
2993 Changes affecting future timestamps
2995 Turks & Caicos is switching from US eastern time to UT -04
2996 year-round, modeled as a switch on 2014-11-02 at 02:00.
2997 [As noted in 2014j, this switch was later delayed.]
2999 Changes affecting past timestamps
3001 Time in Russia or the USSR before 1926 or so has been corrected by
3002 a few seconds in the following zones: Asia/Irkutsk,
3003 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
3004 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
3005 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
3006 Vladimir Karpinsky.)
3008 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
3009 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
3010 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
3011 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
3012 (Thanks to Stephen Colebourne for pointing to the decree.)
3014 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
3016 A new file 'backzone' contains data which may appeal to
3017 connoisseurs of old timestamps, although it is out of scope for
3018 the tz database, is often poorly sourced, and contains some data
3019 that is known to be incorrect. The new file is not recommended
3020 for ordinary use and its entries are not installed by default.
3021 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
3022 Isle of Man entries.)
3024 Some more zones have been turned into links, when they differed
3025 from existing zones only for older timestamps. As usual,
3026 these changes affect UT offsets in pre-1970 timestamps only.
3027 Their old contents have been moved to the 'backzone' file.
3028 The affected zones are: Africa/Bangui, Africa/Brazzaville,
3029 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
3030 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
3032 Changes affecting code
3034 Unless NETBSD_INSPIRED is defined to 0, the tz library now
3035 supplies functions for creating and using objects that represent
3036 timezones. The new functions are tzalloc, tzfree, localtime_rz,
3037 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
3038 time2posix_z. They are intended for performance: for example,
3039 localtime_rz (unlike localtime_r) is trivially thread-safe without
3040 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
3041 functions, and to Alan Barrett and Jonathan Lennox for helping to
3044 zdump now builds with the tz library unless USE_LTZ is defined to 0,
3045 This lets zdump use tz features even if the system library lacks them.
3046 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
3047 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
3049 zdump now uses localtime_rz if available, as it's significantly faster,
3050 and it can help zdump better diagnose invalid timezone names.
3051 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
3052 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
3053 not available, zdump now uses localtime_r and tzset if available,
3054 as this is a bit cleaner and faster than plain localtime. Compile
3055 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
3056 lacks these two functions.
3058 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
3059 Although not needed for tz's own applications, which are single-threaded,
3060 this supports POSIX better if the tz library is used in multithreaded apps.
3062 Some crashes have been fixed when zdump or the tz library is given
3063 invalid or outlandish input.
3065 The tz library no longer mishandles leap seconds on platforms with
3066 unsigned time_t in timezones that lack ordinary transitions after 1970.
3068 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
3069 already defined, to make it easier to configure on common platforms.
3070 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
3072 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
3073 assumes that reading uninitialized memory yields garbage values
3074 but does not cause other problems such as traps.
3076 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
3077 more likely to guess right for ambiguous timestamps near
3078 transitions where tm_isdst does not change.
3080 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
3081 strftime_l for compatibility with recent versions of POSIX.
3082 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
3083 to 1 on recent POSIX versions, and to 0 otherwise.
3085 tzselect -c now uses a hybrid distance measure that works better
3086 in Africa. (Thanks to Alan Barrett for noting the problem.)
3088 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
3089 or when time_tz is defined.
3091 When HAVE_UTMPX_H is set the 'date' command now builds on systems
3092 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
3093 the date it updates the wtmpx file if _PATH_WTMPX is defined.
3094 This affects GNU/Linux and similar systems.
3096 For easier maintenance later, some C code has been simplified,
3097 some lint has been removed, and the code has been tweaked so that
3098 plain 'make' is more likely to work.
3100 The C type 'bool' is now used for boolean values, instead of 'int'.
3102 The long-obsolete LOCALE_HOME code has been removed.
3104 The long-obsolete 'gtime' function has been removed.
3106 Changes affecting build procedure
3108 'zdump' no longer links in ialloc.o, as it's not needed.
3110 'make check_time_t_alternatives' no longer assumes GNU diff.
3112 Changes affecting distribution tarballs
3114 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
3115 the tzdata tarball instead of the tzcode tarball, since they help
3116 maintain the data. The NEWS and Theory files are now also
3117 distributed in the tzdata tarball, as they're relevant for data.
3118 (Thanks to Alan Barrett for pointing this out.) Also, the
3119 leapseconds.awk file is no longer distributed in the tzcode
3120 tarball, since it belongs in the tzdata tarball (where 2014f
3121 inadvertently also distributed it).
3123 Changes affecting documentation and commentary
3125 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
3126 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
3129 The man pages have been updated to use function prototypes,
3130 to document thread-safe variants like localtime_r, and to document
3131 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
3134 The fields in Link lines have been renamed to be more descriptive
3135 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
3136 and LINK-TO has become LINK-NAME.
3138 tz-link.htm mentions the IETF's tzdist working group; Windows
3139 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
3141 Some broken URLs have been fixed in the commentary. (Thanks to
3144 Commentary about Philippines DST has been updated, and commentary
3145 on pre-1970 time in India has been added.
3148 Release 2014f - 2014-08-05 17:42:36 -0700
3150 Changes affecting future timestamps
3152 Russia will subtract an hour from most of its time zones on 2014-10-26
3153 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
3154 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
3155 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
3156 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
3157 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
3158 (Europe/Samara) are not changing their clocks. The changed zones are
3159 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
3160 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
3161 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
3162 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
3163 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
3164 but not its UTC offset. Two zones are added: Asia/Chita (split
3165 from Asia/Yakutsk, and also with two hours subtracted) and
3166 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
3167 subtracted). (Thanks to Tim Parenti for much of the above.)
3169 Changes affecting time zone abbreviations
3171 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3172 and similarly for the other Australian zones. That is, for eastern
3173 standard and daylight saving time the abbreviations are AEST and AEDT
3174 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3175 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3176 This change does not affect UT offsets, only time zone abbreviations.
3177 (Thanks to Rich Tibbett and many others.)
3179 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3180 effective 2014-10-26 at 02:00 local time.
3182 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3183 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3185 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3186 Similarly, prefer EET/EEST for eastern European time in Russia.
3188 Change time zone abbreviations in (western) Samoa to use "ST" and
3189 "DT" suffixes, as this is more likely to match common practice.
3190 Prefix "W" to (western) Samoa time when its standard-time offset
3191 disagrees with that of American Samoa.
3193 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3195 Time zone abbreviations have been updated for Japan's two time
3196 zones used 1896-1937. JWST now stands for Western Standard
3197 Time, and JCST for Central Standard Time (formerly this was CJT).
3198 These abbreviations are now used for time in Korea, Taiwan,
3199 and Sakhalin while controlled by Japan.
3201 Changes affecting past timestamps
3203 China's five zones have been simplified to two, since the post-1970
3204 differences in the other three seem to have been imaginary. The
3205 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3206 removed; backwards-compatibility links still work, albeit with
3207 different behaviors for timestamps before May 1980. Asia/Urumqi's
3208 1980 transition to UT +08 has been removed, so that it is now at
3209 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3210 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3212 Some zones have been turned into links, when they differed from existing
3213 zones only for older UT offsets where data entries were likely invented.
3214 These changes affect UT offsets in pre-1970 timestamps only. This is
3215 similar to the change in release 2013e, except this time for western
3216 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3217 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3218 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3219 Atlantic/St_Helena. This also affects the backwards-compatibility
3220 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3221 Tim Parenti, and David Patte for reporting problems in earlier
3222 versions of this change.)
3224 Asia/Shanghai's pre-standard-time UT offset has been changed from
3225 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3226 transition to standard time has been changed from 1928 to 1901.
3228 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3229 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3230 In 1946 it observed DST from 05-15 through 09-30; in 1947
3231 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3232 (Thanks to Yu-Cheng Chuang.)
3234 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3236 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3237 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3239 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3240 period from 1911 to 1950.
3242 Pacific/Chatham has been changed to New Zealand standard time plus
3243 45 minutes for the period before 1957, reflecting a 1956 remark in
3244 the New Zealand parliament.
3246 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3247 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3248 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3249 not 04-06 at 02:00; and there was no DST in 1920.
3251 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3253 Time in Russia before 1927 or so has been corrected by a few seconds in
3254 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3255 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3256 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3257 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3259 Changes affecting data format
3261 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3262 The new file's extended format allows multiple country codes per zone.
3263 The older file is still installed but is deprecated; its format is
3264 not changing and it will still be distributed for a while, but new
3265 applications should use the new file.
3267 The new file format simplifies maintenance of obscure locations.
3268 To test this, it adds coverage for the Crozet Islands and the
3269 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3271 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3272 It is still ASCII now, but commentary about the switch has been added.
3273 The new file 'zone1970.tab' already uses UTF-8.
3275 Changes affecting code
3277 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3278 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3280 'zic' no longer mishandles input when ignoring case in locales that
3281 are not compatible with English, e.g., unibyte Turkish locales when
3282 compiled with HAVE_GETTEXT.
3284 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3285 they no longer use ASCII '-' as if it were a dash.
3287 'zic' now rejects output file names that contain '.' or '..' components.
3288 (Thanks to Tim Parenti for reporting the problem.)
3290 'zic -v' now warns about output file names that do not follow
3291 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3292 David Olson for starting the ball rolling on this.)
3294 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3296 Changes affecting build procedure
3298 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3299 (Thanks to John Cochran.)
3301 Changes affecting documentation and commentary
3303 The 'Theory' file documents legacy names, the longstanding
3304 exceptions to the POSIX-inspired file name rules.
3306 The 'zic' documentation clarifies the role of time types when
3307 interpreting dates. (Thanks to Arthur David Olson.)
3309 Documentation and commentary now prefer UTF-8 to US-ASCII,
3310 allowing the use of proper accents in foreign words and names.
3311 Code and data have not changed because of this. (Thanks to
3312 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3315 Non-HTML documentation and commentary now use plain-text URLs instead of
3316 HTML insertions, and are more consistent about bracketing URLs when they
3317 are not already surrounded by white space. (Thanks to suggestions by
3320 There is new commentary about Xujiahui Observatory, the five time-zone
3321 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3322 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3323 warlord Jin Shuren in the data.
3325 Commentary about the coverage of each Russian zone has been standardized.
3326 (Thanks to Tim Parenti.)
3328 There is new commentary about contemporary timekeeping in Ethiopia.
3330 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3332 There is new commentary about time in Poland in 1919.
3334 Proper credit has been given to DST inventor George Vernon Hudson.
3336 Commentary about time in Metlakatla, AK and Resolute, NU has been
3337 improved, with a new source for the former.
3339 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3342 Commentary about permanent Antarctic bases has been updated.
3344 Several typos have been corrected. (Thanks to Tim Parenti for
3345 contributing some of these fixes.)
3347 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3348 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3349 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3350 (Thanks to a heads-up from Dirkjan Ochtman.)
3352 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3353 have been removed. These obsolescent US Naval Observatory entries were no
3354 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3357 Release 2014e - 2014-06-12 21:53:52 -0700
3359 Changes affecting near-future timestamps
3361 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3362 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3363 switch to standard time at 24:00 the last Thursday before Ramadan, and
3364 back to DST at 00:00 the first Friday after Ramadan.
3366 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3367 to Milamber Space Network.) Guess that from 2015 on Morocco will
3368 temporarily switch to standard time at 03:00 the last Saturday before
3369 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3371 Changes affecting past timestamps
3373 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3374 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3375 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3376 in 1991. (Thanks to Hank W. for reporting the problems.)
3378 Changes affecting commentary
3380 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3381 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3382 removes stale pointers to World Time Explorer and WORLDTIME.
3385 Release 2014d - 2014-05-27 21:34:40 -0700
3387 Changes affecting code
3389 zic no longer generates files containing timestamps before the Big Bang.
3390 This works around GNOME glib bug 878
3391 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3392 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3393 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3395 Changes affecting documentation
3397 tz-link.htm now mentions GNOME.
3400 Release 2014c - 2014-05-13 07:44:13 -0700
3402 Changes affecting near-future timestamps
3404 Egypt observes DST starting 2014-05-15 at 24:00.
3405 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3406 Details have not been announced, except that DST will not be observed
3407 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3408 Morocco, and that Egypt's future spring and fall transitions will be the
3409 same as 2010 when it last observed DST, namely April's last Friday at
3410 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3411 that Ramadan transitions will be at 00:00 standard time.
3413 Changes affecting code
3415 zic now generates transitions for minimum time values, eliminating guesswork
3416 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3418 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3420 Changes affecting commentary and documentation
3422 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3425 Release 2014b - 2014-03-24 21:28:50 -0700
3427 Changes affecting near-future timestamps
3429 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3430 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3432 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3433 Bengt-Inge Larsson.) This is currently an approximation; a better version
3434 will require the zic and localtime fixes mentioned below, and the plan is
3435 to wait for a while until at least the zic fixes propagate.
3437 Changes affecting code
3439 'zic' and 'localtime' no longer reject locations needing four transitions
3440 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3441 Also, 'zic' avoids some unlikely failures due to integer overflow.
3443 Changes affecting build procedure
3445 'make check' now detects Rule lines defined but never used.
3446 The NZAQ rules, an instance of this problem, have been removed.
3448 Changes affecting commentary and documentation
3450 Fix Tuesday/Thursday typo in description of time in Israel.
3451 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3453 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3454 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3455 library supports them.
3457 Add comments about Johnston Island time in the 1960s.
3458 (Thanks to Lyle McElhaney.)
3460 Morocco's 2014 DST start will be as predicted.
3461 (Thanks to Sebastien Willemijns.)
3464 Release 2014a - 2014-03-07 23:30:29 -0800
3466 Changes affecting near-future timestamps
3468 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3469 the heads-up, and to Tim Parenti for simplifying the update.)
3471 Changes affecting past timestamps
3473 Fiji ended DST on 2014-01-19 at 02:00, not the previously-scheduled 03:00.
3474 (Thanks to Steffen Thorsen.)
3476 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3477 (not 1992-01-01), and observed DST during the entire next winter.
3478 (Thanks to Vladimir in Moscow via Alois Treindl.)
3480 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3481 (Thanks to Avigdor Finkelstein.)
3483 Changes affecting code
3485 A uninitialized-storage bug in 'localtime' has been fixed.
3486 (Thanks to Logan Chien.)
3488 Changes affecting the build procedure
3490 The settings for 'make check_web' now default to Ubuntu 13.10.
3492 Changes affecting commentary and documentation
3494 The boundary of the US Pacific time zone is given more accurately.
3495 (Thanks to Alan Mintz.)
3497 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3499 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3501 Better descriptions of countries with same time zone history as
3502 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3504 Several changes affect tz-link.htm, the main web page.
3506 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3509 Mention xCal (Internet RFC 6321) and jCal.
3511 Microsoft has some support for tz database names.
3513 CLDR data formats include both XML and JSON.
3515 Mention Maggiolo's map of solar vs standard time.
3516 (Thanks to Arthur David Olson.)
3518 Mention TZ4Net. (Thanks to Matt Johnson.)
3520 Mention the timezone-olson Haskell package.
3522 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3524 Remove moribund links to daylight-savings-time.info and to
3525 Simple Timer + Clocks.
3527 Update two links. (Thanks to Oscar van Vlijmen.)
3529 Fix some formatting glitches, e.g., remove random newlines from
3530 abbr elements' title attributes.
3533 Release 2013i - 2013-12-17 07:25:23 -0800
3535 Changes affecting near-future timestamps:
3537 Jordan switches back to standard time at 00:00 on December 20, 2013.
3538 The 2006-2011 transition schedule is planned to resume in 2014.
3539 (Thanks to Steffen Thorsen.)
3541 Changes affecting past timestamps:
3543 In 2004, Cuba began DST on March 28, not April 4.
3544 (Thanks to Steffen Thorsen.)
3546 Changes affecting code
3548 The compile-time flag NOSOLAR has been removed, as nowadays the
3549 benefit of slightly shrinking runtime table size is outweighed by the
3550 cost of disallowing potential future updates that exceed old limits.
3552 Changes affecting documentation and commentary
3554 The files solar87, solar88, and solar89 are no longer distributed.
3555 They were a negative experiment - that is, a demonstration that
3556 tz data can represent solar time only with some difficulty and error.
3557 Their presence in the distribution caused confusion, as Riyadh
3558 civil time was generally not solar time in those years.
3560 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3563 Release 2013h - 2013-10-25 15:32:32 -0700
3565 Changes affecting current and future timestamps:
3567 Libya has switched its UT offset back to +02 without DST, instead
3568 of +01 with DST. (Thanks to Even Scharning.)
3570 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3571 (Thanks to Gwillim Law.)
3573 Changes affecting future timestamps:
3575 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3576 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3577 (Thanks to Steffen Thorsen.)
3579 Add entries for DST transitions in Morocco in the year 2038.
3580 This avoids some year-2038 glitches introduced in 2013g.
3581 (Thanks to Yoshito Umaoka for reporting the problem.)
3583 Changes affecting API
3585 The 'tzselect' command no longer requires the 'select' command,
3586 and should now work with /bin/sh on more platforms. It also works
3587 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3588 Patrick 'P. J.' McDermott and Alan Barrett.)
3590 Changes affecting code
3592 Fix localtime overflow bugs with 32-bit unsigned time_t.
3594 zdump no longer assumes sscanf returns maximal values on overflow.
3596 Changes affecting the build procedure
3598 The builder can specify which programs to use, if any, instead of
3599 'ar' and 'ranlib', and libtz.a is now built locally before being
3600 installed. (Thanks to Michael Forney.)
3602 A dependency typo in the 'zdump' rule has been fixed.
3603 (Thanks to Andrew Paprocki.)
3605 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3606 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3608 'make clean' no longer removes 'leapseconds', since it's
3609 host-independent and is part of the distribution.
3611 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3613 Changes affecting documentation and commentary
3615 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3616 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3618 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3619 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3620 longer maintained) and for old advisories. SOFA now does C.
3622 Release 2013g - 2013-09-30 21:08:26 -0700
3624 Changes affecting current and near-future timestamps
3626 Morocco now observes DST from the last Sunday in March to the last
3627 Sunday in October, not April to September respectively. (Thanks
3628 to Steffen Thorsen.)
3630 Changes affecting 'zic'
3632 'zic' now runs on platforms that lack both hard links and symlinks.
3633 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3634 Also, fix some bugs on platforms that lack hard links but have symlinks.
3636 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3637 to predict the far future, fixing a bug introduced in 2013e.
3639 Changes affecting the build procedure
3641 The 'leapseconds' file is again put into the tzdata tarball.
3642 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3643 Matt Burgess and Ian Abbott.) The timestamps of these and other
3644 dependent files in tarballs are adjusted more consistently.
3646 Changes affecting documentation and commentary
3648 The README file is now part of the data tarball as well as the code.
3649 It now states that files are public domain unless otherwise specified.
3650 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3651 Its details about the 1989 release moved to a place of honor near
3655 Release 2013f - 2013-09-24 23:37:36 -0700
3657 Changes affecting near-future timestamps
3659 Tocantins will very likely not observe DST starting this spring.
3660 (Thanks to Steffen Thorsen.)
3662 Jordan will likely stay at UT +03 indefinitely, and will not fall
3665 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3667 Changes affecting API
3669 The types of the global variables 'timezone' and 'altzone' (if present)
3670 have been changed back to 'long'. This is required for 'timezone'
3671 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3672 These variables were originally 'long' in the tz code, but were
3673 mistakenly changed to 'time_t' in 1987; nobody reported the
3674 incompatibility until now. The difference matters on x32, where
3675 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3677 Changes affecting the build procedure
3679 Avoid long strings in leapseconds.awk to work around a mawk bug.
3680 (Thanks to Cyril Baurand.)
3682 Changes affecting documentation and commentary
3684 New file 'NEWS' that contains release notes like this one.
3686 Paraguay's law does not specify DST transition time; 00:00 is customary.
3687 (Thanks to Waldemar Villamayor-Venialbo.)
3689 Minor capitalization fixes.
3691 Changes affecting version-control only
3693 The experimental GitHub repository now contains annotated and
3694 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3695 Releases are tagged starting with 2012e; earlier releases were
3696 done differently, and tags would either not have a simple name or
3697 not exactly match what was released.
3699 'make set-timestamps' is now simpler and a bit more portable.
3702 Release 2013e - 2013-09-19 23:50:04 -0700
3704 Changes affecting near-future timestamps
3706 This year Fiji will start DST on October 27, not October 20.
3707 (Thanks to David Wheeler for the heads-up.) For now, guess that
3708 Fiji will continue to spring forward the Sunday before the fourth
3711 Changes affecting current and future time zone abbreviations
3713 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3714 time zone abbreviations since 1932. (Thanks to George Ziegler,
3715 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3716 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3717 Asia/Makassar, and Asia/Pontianak.
3719 Use ART (UT -03, standard time), rather than WARST (also -03, but
3720 daylight saving time) for San Luis, Argentina since 2009.
3722 Changes affecting Godthåb timestamps after 2037 if version mismatch
3724 Allow POSIX-like TZ strings where the transition time's hour can
3725 range from -167 through 167, instead of the POSIX-required 0
3726 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3727 new Fiji rules. This is a more-compact way to represent
3728 far-future timestamps for America/Godthab, America/Santiago,
3729 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3730 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3731 this change. (Derived from a suggestion by Arthur David Olson.)
3733 Allow POSIX-like TZ strings where daylight saving time is in
3734 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3735 Argentina Summer Time all year. This supports a more-compact way
3736 to represent the 2013d data for America/Argentina/San_Luis.
3737 Because of the change for San Luis noted above this change does not
3738 affect the current data. (Thanks to Andrew Main (Zefram) for
3739 suggestions that improved this change.)
3741 Where these two TZ changes take effect, there is a minor extension
3742 to the tz file format in that it allows new values for the
3743 embedded TZ-format string, and the tz file format version number
3744 has therefore been increased from 2 to 3 as a precaution.
3745 Version-2-based client code should continue to work as before for
3746 all timestamps before 2038. Existing version-2-based client code
3747 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3748 files, and typically works in practice even for timestamps after
3749 2037; the only known exception is America/Godthab.
3751 Changes affecting timestamps before 1970
3753 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3754 some errors before 1947.
3756 Some zones have been turned into links, when they differ from existing
3757 zones only in older data entries that were likely invented or that
3758 differ only in LMT or transitions from LMT. These changes affect
3759 only timestamps before 1943. The affected zones are:
3760 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3761 America/Grenada, America/Guadeloupe, America/Marigot,
3762 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3763 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3764 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3765 confirming that the old Europe/Vaduz zone was wrong and the new
3766 link is better for WWII-era times.)
3768 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3769 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3772 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3773 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3776 Change the date of the circa-1850 Zurich transition from 1849-09-12
3777 to 1853-07-16, overriding Shanks with data from Messerli about
3778 postal and telegraph time in Switzerland.
3780 Changes affecting time zone abbreviations before 1970
3782 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3783 as Jakarta was called Batavia back then.
3785 Changes affecting API
3787 The 'zic' command now outputs a dummy transition when far-future
3788 data can't be summarized using a TZ string, and uses a 402-year
3789 window rather than a 400-year window. For the current data, this
3790 affects only the Asia/Tehran file. It does not affect any of the
3791 timestamps that this file represents, so zdump outputs the same
3792 information as before. (Thanks to Andrew Main (Zefram).)
3794 The 'date' command has a new '-r' option, which lets you specify
3795 the integer time to display, a la FreeBSD.
3797 The 'tzselect' command has two new options '-c' and '-n', which lets you
3798 select a zone based on latitude and longitude.
3800 The 'zic' command's '-v' option now warns about constructs that
3801 require the new version-3 binary file format. (Thanks to Arthur
3802 David Olson for the suggestion.)
3804 Support for floating-point time_t has been removed.
3805 It was always dicey, and POSIX no longer requires it.
3806 (Thanks to Eric Blake for suggesting to the POSIX committee to
3807 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
3808 Heninger, Arthur David Olson, and Alois Treindl, for reporting
3809 bugs and elucidating some of the corners of the old floating-point
3812 The signatures of 'offtime', 'timeoff', and 'gtime' have been
3813 changed back to the old practice of using 'long' to represent UT
3814 offsets. This had been inadvertently and mistakenly changed to
3815 'int_fast32_t'. (Thanks to Christos Zoulas.)
3817 The code avoids undefined behavior on integer overflow in some
3818 more places, including gmtime, localtime, mktime and zdump.
3820 Changes affecting the zdump utility
3822 zdump now outputs "UT" when referring to Universal Time, not "UTC".
3823 "UTC" does not make sense for timestamps that predate the introduction
3824 of UTC, whereas "UT", a more-generic term, does. (Thanks to Steve Allen
3825 for clarifying UT vs UTC.)
3827 Data changes affecting behavior of tzselect and similar programs
3829 Country code BQ is now called the more-common name "Caribbean Netherlands"
3830 rather than the more-official "Bonaire, St Eustatius & Saba".
3832 Remove from zone.tab the names America/Montreal, America/Shiprock,
3833 and Antarctica/South_Pole, as they are equivalent to existing
3834 same-country-code zones for post-1970 timestamps. The data entries for
3835 these names are unchanged, so the names continue to work as before.
3837 Changes affecting code internals
3839 zic -c now runs way faster on 64-bit hosts when given large numbers.
3841 zic now uses vfprintf to avoid allocating and freeing some memory.
3843 tzselect now computes the list of continents from the data,
3844 rather than have it hard-coded.
3846 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
3848 Changes affecting the build procedure
3850 The 'leapseconds' file is now generated automatically from a
3851 new file 'leap-seconds.list', which is a copy of
3852 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
3853 A new source file 'leapseconds.awk' implements this.
3854 The goal is simplification of the future maintenance of 'leapseconds'.
3856 When building the 'posix' or 'right' subdirectories, if the
3857 subdirectory would be a copy of the default subdirectory, it is
3858 now made a symbolic link if that is supported. This saves about
3859 2 MB of file system space.
3861 The links America/Shiprock and Antarctica/South_Pole have been
3862 moved to the 'backward' file. This affects only nondefault builds
3863 that omit 'backward'.
3865 Changes affecting version-control only
3867 .gitignore now ignores 'date'.
3869 Changes affecting documentation and commentary
3871 Changes to the 'tzfile' man page
3873 It now mentions that the binary file format may be extended in
3874 future versions by appending data.
3876 It now refers to the 'zdump' and 'zic' man pages.
3878 Changes to the 'zic' man page
3880 It lists conditions that elicit a warning with '-v'.
3882 It says that the behavior is unspecified when duplicate names
3883 are given, or if the source of one link is the target of another.
3885 Its examples are updated to match the latest data.
3887 The definition of white space has been clarified slightly.
3888 (Thanks to Michael Deckers.)
3890 Changes to the 'Theory' file
3892 There is a new section about the accuracy of the tz database,
3893 describing the many ways that errors can creep in, and
3894 explaining why so many of the pre-1970 timestamps are wrong or
3895 misleading (thanks to Steve Allen, Lester Caine, and Garrett
3896 Wollman for discussions that contributed to this).
3898 The 'Theory' file describes LMT better (this follows a
3899 suggestion by Guy Harris).
3901 It refers to the 2013 edition of POSIX rather than the 2004 edition.
3903 It's mentioned that excluding 'backward' should not affect the
3904 other data, and it suggests at least one zone.tab name per
3905 inhabited country (thanks to Stephen Colebourne).
3907 Some longstanding restrictions on names are documented, e.g.,
3908 'America/New_York' precludes 'America/New_York/Bronx'.
3910 It gives more reasons for the 1970 cutoff.
3912 It now mentions which time_t variants are supported, such as
3913 signed integer time_t. (Thanks to Paul Goyette for reporting
3914 typos in an experimental version of this change.)
3916 (Thanks to Philip Newton for correcting typos in these changes.)
3918 Documentation and commentary is more careful to distinguish UT in
3919 general from UTC in particular. (Thanks to Steve Allen.)
3921 Add a better source for the Zurich 1894 transition.
3922 (Thanks to Pierre-Yves Berger.)
3924 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
3927 Release 2013d - 2013-07-05 07:38:01 -0700
3929 Changes affecting future timestamps:
3931 Morocco's midsummer transitions this year are July 7 and August 10,
3932 not July 9 and August 8. (Thanks to Andrew Paprocki.)
3934 Israel now falls back on the last Sunday of October.
3935 (Thanks to Ephraim Silverberg.)
3937 Changes affecting past timestamps:
3939 Specify Jerusalem's location more precisely; this changes the pre-1880
3942 Changing affecting metadata only:
3944 Fix typos in the entries for country codes BQ and SX.
3946 Changes affecting code:
3948 Rework the code to fix a bug with handling Australia/Macquarie on
3949 32-bit hosts (thanks to Arthur David Olson).
3951 Port to platforms like NetBSD, where time_t can be wider than long.
3953 Add support for testing time_t types other than the system's.
3954 Run 'make check_time_t_alternatives' to try this out.
3955 Currently, the tests fail for unsigned time_t;
3956 this should get fixed at some point.
3958 Changes affecting documentation and commentary:
3960 Deemphasize the significance of national borders.
3962 Update the zdump man page.
3964 Remove obsolete NOID comment (thanks to Denis Excoffier).
3966 Update several URLs and comments in the web pages.
3968 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
3970 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
3973 Release 2013c - 2013-04-19 16:17:40 -0700
3975 Changes affecting current and future timestamps:
3977 Palestine observed DST starting March 29, 2013. (Thanks to
3978 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
3979 with the predicted rules being the last Thursday in March at 24:00
3980 to the first Friday on or after September 21 at 01:00.
3982 Assume that the recent change to Paraguay's DST rules is permanent,
3983 by moving the end of DST to the 4th Sunday in March every year.
3984 (Thanks to Carlos Raúl Perasso.)
3986 Changes affecting past timestamps:
3988 Fix some historical data for Palestine to agree with that of
3989 timeanddate.com, as follows:
3991 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
3994 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
3997 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
3999 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
4001 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
4003 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
4005 Fix times of habitation for Macquarie to agree with the Tasmania
4006 Parks & Wildlife Service history, which indicates that permanent
4007 habitation was 1899-1919 and 1948 on.
4009 Changing affecting metadata only:
4011 Macquarie Island is politically part of Australia, not Antarctica.
4012 (Thanks to Tobias Conradi.)
4014 Sort Macquarie more-consistently with other parts of Australia.
4015 (Thanks to Tim Parenti.)
4018 Release 2013b - 2013-03-10 22:33:40 -0700
4020 Changes affecting current and future timestamps:
4022 Haiti uses US daylight-saving rules this year, and presumably future years.
4023 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
4025 Paraguay will end DST on March 24 this year.
4026 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
4028 Morocco does not observe DST during Ramadan;
4029 try to predict Ramadan in Morocco as best we can.
4030 (Thanks to Erik Homoet for the heads-up.)
4032 Changes affecting commentary:
4034 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
4035 Update URL for Solaris. Mention Internet RFC 6557.
4036 Update Internet RFCs 2445->5545, 2822->5322.
4037 Switch from FTP to HTTP for Internet RFCs.
4040 Release 2013a - 2013-02-27 09:20:35 -0800
4042 Change affecting binary data format:
4044 The zone offset at the end of version-2-format zone files is now
4045 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
4047 Changes affecting current and future timestamps:
4049 Chile's 2013 rules, and we guess rules for 2014 and later, will be
4050 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
4051 (Thanks to Steffen Thorsen and Robert Elz.)
4053 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
4054 (Thanks to Tobias Conradi and Arthur David Olson.)
4056 Many changes affect historical timestamps before 1940.
4057 These were deduced from: Milne J. Civil time. Geogr J. 1899
4058 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
4060 Changes affecting the code:
4062 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
4063 the data). (Thanks to Arthur David Olson.)
4065 Fix localtime bug when time_t is unsigned and data files were generated
4066 by a signed time_t system. (Thanks to Doug Bailey for reporting and
4067 to Arthur David Olson for fixing.)
4069 Allow the email address for bug reports to be set by the packager.
4070 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
4072 Update HTML checking to be compatible with Ubuntu 12.10.
4074 Check that files are a safe subset of ASCII. At some point we may
4075 relax this requirement to a safe subset of UTF-8. Without the
4076 check, some non-UTF-8 encodings were leaking into the distribution.
4080 Restore a comment about copyright notices that was inadvertently deleted.
4081 (Thanks to Arthur David Olson.)
4083 Improve the commentary about which districts observe what times
4084 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
4086 Add web page links to tz.js.
4088 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
4091 Release 2012j - 2012-11-12 18:34:49 -0800
4093 Libya moved to CET this weekend, but with DST planned next year.
4094 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
4096 Signatures now have the extension .asc, not .sign, as that's more
4097 standard. (Thanks to Phil Pennock.)
4099 The output of 'zdump --version', and of 'zic --version', now
4100 uses a format that is more typical for --version.
4101 (Thanks to Joseph S. Myers.)
4103 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
4104 now uses tz@iana.org rather than the old elsie address.
4106 zic -v now complains about abbreviations that are less than 3
4107 or more than 6 characters, as per Posix. Formerly, it checked
4108 for abbreviations that were more than 3.
4110 'make public' no longer puts its temporary directory under /tmp,
4111 and uses the just-built zic rather than the system zic.
4113 Various fixes to documentation and commentary.
4116 Release 2012i - 2012-11-03 12:57:09 -0700
4118 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
4120 Linker flags can now be specified via LDFLAGS.
4121 AWK now defaults to 'awk', not 'nawk'.
4122 The shell in tzselect now defaults to /bin/bash, but this can
4123 be overridden by specifying KSHELL.
4124 The main web page now mentions the unofficial GitHub repository.
4125 (Thanks to Mike Frysinger.)
4127 Tarball signatures can now be built by running 'make signatures'.
4128 There are also new makefile rules 'tarballs', 'check_public', and
4129 separate makefile rules for each tarball and signature file.
4130 A few makefile rules are now more portable to strict POSIX.
4132 The main web page now lists the canonical IANA URL.
4135 Release 2012h - 2012-10-26 22:49:10 -0700
4137 Bahia no longer has DST. (Thanks to Kelley Cook.)
4139 Tocantins has DST. (Thanks to Rodrigo Severo.)
4141 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
4143 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
4147 More C modernization, except that at Arthur David Olson's suggestion
4148 the instances of 'register' were kept.
4151 Release 2012g - 2012-10-17 20:59:45 -0700
4153 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
4155 Palestine fall 2012. (Thanks to Steffen Thorsen.)
4159 To attack the version-number problem, this release ships the file
4160 'Makefile' (which contains the release number) in both the tzcode and
4161 the tzdata tarballs. The two Makefiles are identical, and should be
4162 identical in any matching pair of tarballs, so it shouldn't matter
4163 which order you extract the tarballs. Perhaps we can come up with a
4164 better version-number scheme at some point; this scheme does have the
4165 virtue of not adding more files.
4168 Release 2012f - 2012-09-12 23:17:03 -0700
4170 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4171 20 this year. (Thanks to Steffen Thorsen.)
4174 Release 2012e - 2012-08-02 20:44:55 -0700
4176 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4177 (Thanks to Steffen Thorsen.)
4179 * Use a single version number for both code and data.
4181 * .gitignore: New file.
4183 * Remove trailing white space.
4186 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4188 Changes for Morocco's timestamps, which take effect in a couple of
4189 hours, along with infrastructure changes to accommodate how the tz
4190 code and data are released on IANA.
4193 Release data2012c - 2012-03-27 12:17:25 -0400
4196 Summer time changes for Morocco (to start late April 2012)
4199 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4202 Haiti following US/Canada rules for 2012 (and we're assuming,
4203 for now anyway, for the future).
4206 Release 2012b - 2012-03-02 12:29:15 +0700
4208 There is just one change to tzcode2012b (compared with 2012a):
4209 the Makefile that was accidentally included with 2012a has been
4210 replaced with the version that should have been there, which is
4211 identical with the previous version (from tzcode2011i).
4213 There are just two changes in tzdata2012b compared with 2012a.
4215 Most significantly, summer time in Cuba has been delayed 3 weeks
4216 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4217 date, as listed in 2012a) is just a little over a week away, this
4220 Less importantly, an excess tab in one of the changes in zone.tab
4221 in 2012a has been removed.
4224 Release 2012a - 2012-03-01 18:28:10 +0700
4226 The changes in tzcode2012a (compared to the previous version, 2011i)
4227 are entirely to the README and tz-art.htm and tz-link.htm files, if
4228 none of those concern you, you can ignore the code update. The changes
4229 reflect the changed addresses for the mailing list and the code and
4230 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4231 has been added to tz-link.htm).
4233 In tzdata2012a (compared to the previous release, which was 2011n)
4234 the major changes are:
4235 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4236 Falkland Islands onto permanent summer time (we're assuming for the
4237 foreseeable future, though 2012 is all we're fairly certain of.)
4238 Armenia has abolished Summer Time.
4239 Tokelau jumped the International Date Line back last December
4240 (just the same as their near neighbour, Samoa).
4241 America/Creston is a new zone for a small area of British Columbia
4242 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4244 Other minor changes are:
4245 Corrections to 1918 Canadian summer time end dates.
4246 Updated URL for UK time zone history (in comments)
4247 A few typos in Le Corre's list of free French place names (comments)
4250 Release data2011n - 2011-10-30 14:57:54 +0700
4252 There are three changes of note - most urgently, Cuba (America/Havana)
4253 has extended summer time by two weeks, now to end on Nov 13, rather than
4254 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4255 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4256 all, and consequently that zone has been removed (again) and reinstated
4257 in the "backward" file as a link to Europe/Chisinau. And third, the
4258 end date for Fiji's summer time this summer was moved forward from the
4259 earlier planned Feb 26, to Jan 22.
4261 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4262 (and the incorrect syntax that was in the 2011m version of that file
4263 is so fixed - it would have been fixed in a different way had this
4264 change not happened - that's the "missing" sccs version id).
4267 Release data2011m - 2011-10-24 21:42:16 +0700
4269 In particular, the typos in comments in the data (2011-11-17 should have
4270 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4271 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4272 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
4273 Tim Parenti, and also Denys Gavrysh)
4275 In addition, I added Europe/Tiraspol to zone.tab.
4277 This time, all the files have new version numbers... (including the files
4278 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4279 version numbers there...)
4282 Release data2011l - 2011-10-10 11:15:43 +0700
4284 There are just 2 changes that cause different generated tzdata files from
4285 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4286 is included, but commented out. Compared with the diff I sent out last week,
4287 this version also includes attributions for the sources for the changes
4288 (in much the same format as ado used, but the html tags have not been
4289 checked, verified, or used in any way at all, so if there are errors there,
4290 please let me know.)
4293 Release data2011k - 2011-09-20 17:54:03 -0400
4298 Release data2011j - 2011-09-12 09:22:49 -0400
4300 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4301 Tanzania); there are also two spelling corrections to comments in
4302 the australasia file (with thanks to Christos Zoulas).
4305 Release 2011i - 2011-08-29 05:56:32 -0400
4310 Release data2011h - 2011-06-15 18:41:48 -0400
4312 Russia and Curaçao changes
4315 Release 2011g - 2011-04-25 09:07:22 -0400
4317 update the rules for Egypt to reflect its abandonment of DST this year
4320 Release 2011f - 2011-04-06 17:14:53 -0400
4325 Release 2011e - 2011-03-31 16:04:38 -0400
4327 Morocco, Chile, and tz-link changes
4330 Release 2011d - 2011-03-14 09:18:01 -0400
4332 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4335 Release 2011c - 2011-03-07 09:30:09 -0500
4337 These do affect current timestamps in Chile and Annette Island, Canada.
4340 Release 2011b - 2011-02-07 08:44:50 -0500
4345 Release 2011a - 2011-01-24 10:30:16 -0500
4350 Release data2010o - 2010-11-01 09:18:23 -0400
4352 change to the end of DST in Fiji in 2011
4355 Release 2010n - 2010-10-25 08:19:17 -0400
4360 Release 2010m - 2010-09-27 09:24:48 -0400
4362 Hong Kong, Vostok, and zic.c changes
4365 Release 2010l - 2010-08-16 06:57:25 -0400
4370 Release 2010k - 2010-07-26 10:42:27 -0400
4375 Release 2010j - 2010-05-10 09:07:48 -0400
4377 changes for Bahía de Banderas and for version naming
4380 Release data2010i - 2010-04-16 18:50:45 -0400
4382 the end of DST in Morocco on 2010-08-08
4385 Release data2010h - 2010-04-05 09:58:56 -0400
4390 Release data2010g - 2010-03-24 11:14:53 -0400
4395 Release 2010f - 2010-03-22 09:45:46 -0400
4400 Release data2010e - 2010-03-08 14:24:27 -0500
4402 corrects the Dhaka bug found by Danvin Ruangchan
4405 Release data2010d - 2010-03-06 07:26:01 -0500
4410 Release 2010c - 2010-03-01 09:20:58 -0500
4412 changes including KRE's suggestion for earlier initialization of
4413 "goahead" and "goback" structure elements
4416 Release code2010a - 2010-02-16 10:40:04 -0500
4421 Release data2010b - 2010-01-20 12:37:01 -0500
4426 Release data2010a - 2010-01-18 08:30:04 -0500
4431 Release data2009u - 2009-12-26 08:32:28 -0500
4433 changes to DST in Bangladesh
4436 Release 2009t - 2009-12-21 13:24:27 -0500
4441 Release data2009s - 2009-11-14 10:26:32 -0500
4443 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4446 Release 2009r - 2009-11-09 10:10:31 -0500
4448 "antarctica" and "tz-link.htm" changes
4451 Release 2009q - 2009-11-02 09:12:40 -0500
4453 with two corrections as reported by Eric Muller and Philip Newton
4456 Release data2009p - 2009-10-23 15:05:27 -0400
4458 Argentina (including San Luis) changes (with the correction from
4462 Release data2009o - 2009-10-14 16:49:38 -0400
4464 Samoa (commentary only), Pakistan, and Bangladesh changes
4467 Release data2009n - 2009-09-22 15:13:38 -0400
4469 added commentary for Argentina and a change to the end of DST in
4473 Release data2009m - 2009-09-03 10:23:43 -0400
4475 Samoa and Palestine changes
4478 Release data2009l - 2009-08-14 09:13:07 -0400
4480 Samoa (comments only) and Egypt
4483 Release 2009k - 2009-07-20 09:46:08 -0400
4488 Release data2009j - 2009-06-15 06:43:59 -0400
4490 Bangladesh change (with a short turnaround since the DST change is
4494 Release 2009i - 2009-06-08 09:21:22 -0400
4496 updating for DST in Bangladesh this year
4499 Release 2009h - 2009-05-26 09:19:14 -0400
4504 Release data2009g - 2009-04-20 16:34:07 -0400
4509 Release data2009f - 2009-04-10 11:00:52 -0400
4511 correct DST in Pakistan
4514 Release 2009e - 2009-04-06 09:08:11 -0400
4519 Release 2009d - 2009-03-23 09:38:12 -0400
4521 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4524 Release data2009c - 2009-03-16 09:47:51 -0400
4526 change to the start of Cuban DST
4529 Release 2009b - 2009-02-09 11:15:22 -0500
4534 Release 2009a - 2009-01-21 10:09:39 -0500
4539 Release data2008i - 2008-10-21 12:10:25 -0400
4541 southamerica and zone.tab files, with Argentina DST rule changes and
4542 United States zone reordering and recommenting
4545 Release 2008h - 2008-10-13 07:33:56 -0400
4550 Release 2008g - 2008-10-06 09:03:18 -0400
4552 Fix a broken HTML anchor and update Brazil's DST transitions;
4553 there's also a slight reordering of information in tz-art.htm.
4556 Release data2008f - 2008-09-09 22:33:26 -0400
4561 Release 2008e - 2008-07-28 14:11:17 -0400
4563 changes by Arthur David Olson and Jesper Nørgaard Welen
4566 Release data2008d - 2008-07-07 09:51:38 -0400
4568 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4571 Release data2008c - 2008-05-19 17:48:03 -0400
4573 Pakistan, Morocco, and Mongolia
4576 Release data2008b - 2008-03-24 08:30:59 -0400
4578 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4582 Release 2008a - 2008-03-08 05:42:16 -0500
4587 Release 2007k - 2007-12-31 10:25:22 -0500
4589 most importantly, changes to the "southamerica" file based on
4590 Argentina's readoption of daylight saving time
4593 Release 2007j - 2007-12-03 09:51:01 -0500
4595 1. eliminate the "P" (parameter) macro;
4597 2. the "noncontroversial" changes circulated on the time zone
4598 mailing list (less the changes to "logwtmp.c");
4600 3. eliminate "too many transition" errors when "min" is used in time
4603 4. changes by Paul Eggert (including updated information for Venezuela).
4606 Release data2007i - 2007-10-30 10:28:11 -0400
4608 changes for Cuba and Syria
4611 Release 2007h - 2007-10-01 10:05:51 -0400
4613 changes by Paul Eggert, as well as an updated link to the ICU
4614 project in tz-link.htm
4617 Release 2007g - 2007-08-20 10:47:59 -0400
4619 changes by Paul Eggert
4621 The "leapseconds" file has been updated to incorporate the most
4622 recent International Earth Rotation and Reference Systems Service
4625 There's an addition to tz-art.htm regarding the television show "Medium".
4628 Release 2007f - 2007-05-07 10:46:46 -0400
4630 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4633 changes to zic.c to allow hour values greater than 24 (along with
4634 Paul's improved time value overflow checking)
4637 Release 2007e - 2007-04-02 10:11:52 -0400
4639 Syria and Honduras changes by Paul Eggert
4641 zic.c variable renaming changes by Arthur David Olson
4644 Release 2007d - 2007-03-20 08:48:30 -0400
4646 changes by Paul Eggert
4648 the elimination of white space at the ends of lines
4651 Release 2007c - 2007-02-26 09:09:37 -0500
4653 changes by Paul Eggert
4656 Release 2007b - 2007-02-12 09:34:20 -0500
4658 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4660 changes to the commentary in "leapseconds" reflecting the IERS
4661 announcement that there is to be no positive leap second at the end
4665 Release 2007a - 2007-01-08 12:28:29 -0500
4667 changes by Paul Eggert
4669 Derick Rethans's Asmara change
4671 Oscar van Vlijmen's Easter Island local mean time change
4673 symbolic link changes
4676 Release 2006p - 2006-11-27 08:54:27 -0500
4678 changes by Paul Eggert
4681 Release 2006o - 2006-11-06 09:18:07 -0500
4683 changes by Paul Eggert
4686 Release 2006n - 2006-10-10 11:32:06 -0400
4688 changes by Paul Eggert
4691 Release 2006m - 2006-10-02 15:32:35 -0400
4693 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4695 (minimalist) changes to zic.8 to clarify "until" information
4698 Release data2006l - 2006-09-18 12:58:11 -0400
4700 Paul's best-effort work on this coming weekend's Egypt time change
4703 Release 2006k - 2006-08-28 12:19:09 -0400
4705 changes by Paul Eggert
4708 Release 2006j - 2006-08-21 09:56:32 -0400
4710 changes by Paul Eggert
4713 Release code2006i - 2006-08-07 12:30:55 -0400
4717 Ken Pizzini's conversion script
4720 Release code2006h - 2006-07-24 09:19:37 -0400
4722 adds public domain notices to four files
4724 includes a fix for transition times being off by a second
4726 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4729 Release 2006g - 2006-05-08 17:18:09 -0400
4731 northamerica changes by Paul Eggert
4734 Release 2006f - 2006-05-01 11:46:00 -0400
4736 a missing version number problem is fixed (with thanks to Bradley
4737 White for catching the problem)
4740 Release 2006d - 2006-04-17 14:33:43 -0400
4742 changes by Paul Eggert
4744 added new items to tz-arts.htm that were found by Paul
4747 Release 2006c - 2006-04-03 10:09:32 -0400
4749 two sets of data changes by Paul Eggert
4751 a fencepost error fix in zic.c
4753 changes to zic.c and the "europe" file to minimize differences
4754 between output produced by the old 32-bit zic and the new 64-bit
4758 Release 2006b - 2006-02-20 10:08:18 -0500
4759 [tz32code2006b + tz64code2006b + tzdata2006b]
4763 All SCCS IDs were bumped to "8.1" for this release.
4766 Release 2006a - 2006-01-30 08:59:31 -0500
4768 changes by Paul Eggert (in particular, Indiana time zone moves)
4770 an addition to the zic manual page to describe how special-case
4771 transitions are handled
4774 Release 2005r - 2005-12-27 09:27:13 -0500
4776 Canadian changes by Paul Eggert
4778 They also add "<pre>" directives to time zone data files and reflect
4779 changes to warning message logic in "zdump.c" (but with calls to
4780 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4783 Release 2005q - 2005-12-13 09:17:09 -0500
4785 Nothing earth-shaking here:
4786 1. Electronic mail addresses have been removed.
4787 2. Casts of the return value of exit have been removed.
4788 3. Casts of the argument of is.* macros have been added.
4789 4. Indentation in one section of zic.c has been fixed.
4790 5. References to dead URLs in the data files have been dealt with.
4793 Release 2005p - 2005-12-05 10:30:53 -0500
4795 "systemv", "tz-link.htm", and "zdump.c" changes
4796 (less the casts of arguments to the is* macros)
4799 Release 2005o - 2005-11-28 10:55:26 -0500
4801 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
4803 zdump.c lint fixes by Arthur David Olson
4806 Release 2005n - 2005-10-03 09:44:09 -0400
4808 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
4812 Release 2005m - 2005-08-29 12:15:40 -0400
4814 changes by Paul Eggert (with a small tweak to the tz-art change)
4816 a declaration of an unused variable has been removed from zdump.c
4819 Release 2005l - 2005-08-22 12:06:39 -0400
4821 changes by Paul Eggert
4823 overflow/underflow checks by Arthur David Olson, minus changes to
4824 the "Theory" file about the pending addition of 64-bit data (I grow
4825 less confident of the changes being accepted with each passing day,
4826 and the changes no longer increase the data files nine-fold--there's
4827 less than a doubling in size by my local Sun's reckoning)
4830 Release 2005k - 2005-07-14 14:14:24 -0400
4832 The "leapseconds" file has been edited to reflect the recently
4833 announced leap second at the end of 2005.
4835 I've also deleted electronic mail addresses from the files as an
4839 Release 2005j - 2005-06-13 14:34:13 -0400
4841 These reflect changes to limit the length of time zone abbreviations
4842 and the characters used in those abbreviations.
4844 There are also changes to handle POSIX-style "quoted" timezone
4845 environment variables.
4847 The changes were circulated on the time zone mailing list; the only
4848 change since then was the removal of a couple of minimum-length of
4849 abbreviation checks.
4852 Release data2005i - 2005-04-21 15:04:16 -0400
4854 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
4857 Release 2005h - 2005-04-04 11:24:47 -0400
4859 changes by Paul Eggert
4861 minor changes to Makefile and zdump.c to produce more useful output
4862 when doing a "make typecheck"
4865 Release 2005g - 2005-03-14 10:11:21 -0500
4867 changes by Paul Eggert (a change to current DST rules in Uruguay and
4868 an update to a link to time zone software)
4871 Release 2005f - 2005-03-01 08:45:32 -0500
4873 data and documentation changes by Paul Eggert
4876 Release 2005e - 2005-02-10 15:59:44 -0500
4881 Release code2005d - 2005-01-31 09:21:47 -0500
4883 make zic complain about links to links if the -v flag is used
4885 have "make public" do more code checking
4887 add an include to "localtime.c" for the benefit of gcc systems
4890 Release 2005c - 2005-01-17 18:36:29 -0500
4892 get better results when mktime runs on a system where time_t is double
4894 changes to the data files (most importantly to Paraguay)
4897 Release 2005b - 2005-01-10 09:19:54 -0500
4899 Get localtime and gmtime working on systems with exotic time_t types.
4901 Update the leap second commentary in the "leapseconds" file.
4904 Release 2005a - 2005-01-01 13:13:44 -0500
4909 Release code2004i - 2004-12-14 13:42:58 -0500
4911 Deal with systems where time_t is unsigned.
4914 Release code2004h - 2004-12-07 11:40:18 -0500
4916 64-bit-time_t changes
4919 Release 2004g - 2004-11-02 09:06:01 -0500
4921 update to Cuba (taking effect this weekend)
4923 other changes by Paul Eggert
4925 correction of the spelling of Oslo
4927 changed versions of difftime.c and private.h
4930 Release code2004f - 2004-10-21 10:25:22 -0400
4932 Cope with wide-ranging tm_year values.
4935 Release 2004e - 2004-10-11 14:47:21 -0400
4937 Brazil/Argentina/Israel changes by Paul Eggert
4939 changes to tz-link.htm by Paul
4941 one small fix to Makefile
4944 Release 2004d - 2004-09-22 08:27:29 -0400
4946 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
4949 Release 2004c - 2004-08-11 12:06:26 -0400
4951 asctime-related changes
4953 (variants of) some of the documentation changes suggested by Paul Eggert
4956 Release 2004b - 2004-07-19 14:33:35 -0400
4958 data changes by Paul Eggert - most importantly, updates for Argentina
4961 Release 2004a - 2004-05-27 12:00:47 -0400
4963 changes by Paul Eggert
4965 Handle DST transitions that occur at the end of a month in some
4966 years but at the start of the following month in other years.
4968 Add a copy of the correspondence that's the basis for claims about
4969 DST in the Navajo Nation.
4972 Release 2003e - 2003-12-15 09:36:47 -0500
4974 changes by Arthur David Olson (primarily code changes)
4976 changes by Paul Eggert (primarily data changes)
4978 minor changes to "Makefile" and "northamerica" (in the latter case,
4979 optimization of the "Toronto" rules)
4982 Release 2003d - 2003-10-06 09:34:44 -0400
4984 changes by Paul Eggert
4987 Release 2003c - 2003-09-16 10:47:05 -0400
4989 Fix bad returns in zic.c's inleap function.
4990 Thanks to Bradley White for catching the problem!
4993 Release 2003b - 2003-09-16 07:13:44 -0400
4995 Add a "--version" option (and documentation) to the zic and zdump commands.
4997 changes to overflow/underflow checking in zic
4999 a localtime typo fix.
5001 Update the leapseconds and tz-art.htm files.
5004 Release 2003a - 2003-03-24 09:30:54 -0500
5006 changes by Paul Eggert
5008 a few additions and modifications to the tz-art.htm file
5011 Release 2002d - 2002-10-15 13:12:42 -0400
5013 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
5015 There's also a new time zone quote in "tz-art.htm".
5018 Release 2002c - 2002-04-04 11:55:20 -0500
5020 changes by Paul Eggert
5022 Change zic.c to avoid creating symlinks to files that don't exist.
5025 Release 2002b - 2002-01-28 12:56:03 -0500
5027 [These change notes are for Release 2002a, which was corrupted.
5028 2002b was a corrected version of 2002a.]
5030 changes by Paul Eggert
5032 Update the "leapseconds" file to note that there'll be no leap
5033 second at the end of June, 2002.
5035 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
5037 Change to "difftime.c" to avoid sizeof problems.
5040 Release 2001d - 2001-10-09 13:31:32 -0400
5042 changes by Paul Eggert
5045 Release 2001c - 2001-06-05 13:59:55 -0400
5047 changes by Paul Eggert and Andrew Brown
5050 Release 2001b - 2001-04-05 16:44:38 -0400
5052 changes by Paul Eggert (modulo jnorgard's typo fix)
5054 tz-art.htm has been HTMLified.
5057 Release 2001a - 2001-03-13 12:57:44 -0500
5059 changes by Paul Eggert
5061 An addition to the "leapseconds" file: comments with the text of the
5062 latest IERS leap second notice.
5064 Trailing white space has been removed from data file lines, and
5065 repeated spaces in "Rule Jordan" lines in the "asia" file have been
5069 Release 2000h - 2000-12-14 15:33:38 -0500
5071 changes by Paul Eggert
5073 one typo fix in the "art" file
5075 With providence, this is the last update of the millennium.
5078 Release 2000g - 2000-10-10 11:35:22 -0400
5080 changes by Paul Eggert
5082 correction of John Mackin's name submitted by Robert Elz
5084 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
5085 Emmy Awards broadcast.
5088 Release 2000f - 2000-08-10 09:31:58 -0400
5090 changes by Paul Eggert
5092 Added information in "tz-art.htm" on a Seinfeld reference to DST.
5094 Error checking and messages in the "yearistype" script have been
5098 Release 2000e - 2000-07-31 09:27:54 -0400
5100 data changes by Paul Eggert
5102 a change to the default value of the defined constant HAVE_STRERROR
5104 the addition of a Dave Barry quote on DST to the tz-arts file
5107 Release 2000d - 2000-04-20 15:43:04 -0400
5109 changes to the documentation and code of strftime for C99 conformance
5111 a bug fix for date.c
5113 These are based on (though modified from) changes by Paul Eggert.
5116 Release 2000c - 2000-03-04 10:31:43 -0500
5118 changes by Paul Eggert
5121 Release 2000b - 2000-02-21 12:16:29 -0500
5123 changes by Paul Eggert and Joseph Myers
5125 modest tweaks to the tz-art.htm and tz-link.htm files
5128 Release 2000a - 2000-01-18 09:21:26 -0500
5130 changes by Paul Eggert
5132 The two hypertext documents have also been renamed.
5135 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
5137 Paul Eggert's changes
5139 additions to the "zic" manual page and the "Arts.htm" file
5142 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
5147 Release data1999h - 1999-10-07 03:50:29 -0400
5149 changes by Paul Eggert to "europe" (most importantly, fixing
5150 Lithuania and Estonia)
5153 Release 1999g - 1999-09-28 11:06:18 -0400
5155 data changes by Paul Eggert (most importantly, the change for
5156 Lebanon that buys correctness for this coming Sunday)
5158 The "code" file contains changes to "Makefile" and "checktab.awk" to
5159 allow better checking of time zone files before they are published.
5162 Release 1999f - 1999-09-23 09:48:14 -0400
5164 changes by Arthur David Olson and Paul Eggert
5167 Release 1999e - 1999-08-17 15:20:54 -0400
5169 changes circulated by Paul Eggert, although the change to handling
5170 of DST-specifying timezone names has been commented out for now
5171 (search for "XXX" in "localtime.c" for details). These files also
5172 do not make any changes to the start of DST in Brazil.
5174 In addition to Paul's changes, there are updates to "Arts.htm" and
5178 Release 1999d - 1999-03-30 11:31:07 -0500
5180 changes by Paul Eggert
5182 The Makefile's "make public" rule has also been changed to do a test
5183 compile of each individual time zone data file (which should help
5184 avoid problems such as the one we had with Nicosia).
5187 Release 1999c - 1999-03-25 09:47:47 -0500
5189 changes by Paul Eggert, most importantly the change for Chile.
5192 Release 1999b - 1999-02-01 17:51:44 -0500
5194 changes by Paul Eggert
5196 code changes (suggested by Mani Varadarajan, mani at be.com) for
5197 correct handling of symbolic links when building using a relative directory
5199 code changes to generate correct messages for failed links
5201 updates to the URLs in Arts.htm
5204 Release 1999a - 1999-01-19 16:20:29 -0500
5206 error message internationalizations and corrections in zic.c and
5207 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5211 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5213 changes for Brazil, Chile, and Germany
5215 support for use of "24:00" in the input files for the time zone compiler
5218 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5220 changes by Paul Eggert
5222 correction to a define in the "private.h" file
5225 Release data1998g - 1998-08-11 03:28:35 -0000
5226 [tzdata1998g.tar.gz is missing!]
5228 Lithuanian change provided by mgedmin at pub.osf.it
5230 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5231 "backward") to ensure that the GMT file is created even where folks
5232 don't want the "backward" links (as suggested by Paul Eggert).
5235 Release data1998f - 1998-07-20 13:50:00 -0000
5236 [tzdata1998f.tar.gz is missing!]
5238 Update the "leapseconds" file to include the newly-announced
5239 insertion at the end of 1998.
5242 Release code1998f - 1998-06-01 10:18:31 -0400
5244 addition to localtime.c by Guy Harris
5247 Release 1998e - 1998-05-28 09:56:26 -0400
5249 The Makefile is changed to produce zoneinfo-posix rather than
5250 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5253 data changes by Paul Eggert
5255 changes from Guy Harris to provide asctime_r and ctime_r
5257 A usno1998 file (substantially identical to usno1997) has been added.
5260 Release 1998d - 1998-05-14 11:58:34 -0400
5262 changes to comments (in particular, elimination of references to CIA maps).
5263 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5264 where changes occur.
5267 Release 1998c - 1998-02-28 12:32:26 -0500
5269 changes by Paul Eggert (save the "French correction," on which I'll
5270 wait for the dust to settle)
5274 changes and additions to Arts.htm
5277 Release 1998b - 1998-01-17 14:31:51 -0500
5279 URL cleanups and additions
5282 Release 1998a - 1998-01-13 12:37:35 -0500
5284 changes by Paul Eggert
5287 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5289 changes by Paul Eggert, with minor modifications from Arthur David
5290 Olson to make the files more browser friendly
5293 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5295 minor changes to put "TZif" at the start of each timezone information file
5297 a rule has also been added to the Makefile so you can
5299 to just recompile the zone information files (rather than doing a
5300 full "make install" with its other effects).
5303 Release data1997i - 1997-10-07 08:45:38 -0400
5305 changes to Africa by Paul Eggert
5308 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5310 corrections for Uruguay (and other locations)
5312 Arthur David Olson's simple-minded fix allowing mktime to both
5313 correctly handle leap seconds and correctly handle tm_sec values
5314 upon which arithmetic has been performed.
5317 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5319 Paul Eggert's updates
5321 a small change to a function prototype;
5323 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5324 include information on Around the World in Eighty Days.
5327 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5329 fixes to zic's error handling
5331 changes inspired by the item circulated on Slovenia
5333 The description of Web resources has been HTMLified for browsing
5336 A new piece of tz-related music has been added to the "Music" file.
5339 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5341 Paul Eggert's latest suggestions
5344 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5346 changes to "zic.c" to correct performance of the "-s" option
5348 a new file "usno1997"
5351 Release data1997c - 1997-03-04 09:58:18 -0500
5356 Release 1997b - 1997-02-27 18:34:19 -0500
5358 The data file incorporates the 1997 leap second.
5360 The code file incorporates Arthur David Olson's take on the
5361 zic/multiprocessor/directory-creation situation.
5364 Release 1997a - 1997-01-21 09:11:10 -0500
5366 Paul Eggert's Antarctica (and other changes)
5368 Arthur David Olson finessed the "getopt" issue by checking against
5369 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5370 is returned while SunOS 5.5's manual says EOF is returned).
5373 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5375 Paul Eggert's latest changes
5378 Release code1996n - 1996-12-16 09:42:02 -0500
5380 link snapping fix from Bruce Evans (via Garrett Wollman)
5383 Release data1996m - 1996-11-24 02:37:34 -0000
5384 [tzdata1996m.tar.gz is missing!]
5386 Paul Eggert's batch of changes
5389 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5391 No functional changes here; the files have simply been changed to
5392 make more use of ISO style dates in comments. The names of the above
5393 files now include the year in full.
5396 Release code96l - 1996-09-08 17:12:20 -0400
5398 tzcode96k was missing a couple of pieces.
5401 Release 96k - 1996-09-08 16:06:22 -0400
5403 the latest round of changes from Paul Eggert
5405 the recent Year 2000 material
5408 Release code96j - 1996-07-30 13:18:53 -0400
5410 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5413 Release code96i - 1996-07-27 20:11:35 -0400
5415 Paul's suggested patch for strftime %V week numbers
5418 Release data96i - 1996-07-01 18:13:04 -0400
5420 "northamerica" and "europe" changes by Paul Eggert
5423 Release code96h - 1996-06-05 08:02:21 -0400
5425 fix for handling transitions specified in Universal Time
5427 Some "public domain" notices have also been added.
5430 Release code96g - 1996-05-16 14:00:26 -0400
5432 fix for the simultaneous-DST-and-zone-change challenge
5435 Release data96h - 1996-05-09 17:40:51 -0400
5437 changes by Paul Eggert
5440 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5441 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5443 The changes get us some of the way to fixing the problems noted in Paul
5444 Eggert's letter yesterday (in addition to a few others). The approach
5445 has been to make zic a bit smarter about figuring out what time zone
5446 abbreviations apply just after the time specified in the "UNTIL" part
5447 of a zone line. Putting the smarts in zic means avoiding having
5448 transition times show up in both "Zone" lines and "Rule" lines, which
5449 in turn avoids multiple transition time entries in time zone files.
5450 (This also makes the zic input files such as "europe" a bit shorter and
5451 should ease maintenance.)
5454 Release data96f - 1996-04-19 19:20:03 -0000
5455 [tzdata96f.tar.gz is missing!]
5457 The only changes are to the "northamerica" file; the time zone
5458 abbreviation for Denver is corrected to MST (and MDT), and the
5459 comments for Mexico have been updated.
5462 Release data96e - 1996-03-19 17:37:26 -0500
5464 Proposals by Paul Eggert, in particular the Portugal change that
5465 comes into play at the end of this month.
5468 Release data96d - 1996-03-18 20:49:39 -0500
5473 Release code96e - 1996-02-29 15:43:27 -0000
5474 [tzcode96e.tar.gz is missing!]
5476 internationalization changes and the fix to the documentation for strftime
5479 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5481 The "code" file simply updates Bob Kridle's electronic address.
5483 The "data" file updates rules for Mexico.
5486 Release data96b - 1996-01-27 15:44:42 -0500
5491 Release code96c - 1996-01-16 16:58:15 -0500
5493 leap-year streamlining and binary-search changes
5498 Release code96b - 1996-01-10 20:42:39 -0500
5500 fixes and enhancements from Paul Eggert, including code that
5501 emulates the behavior of recent versions of the SunOS "date"
5505 Release 96a - 1996-01-06 09:08:24 -0500
5509 fixes to strftime.c for correct ISO 8601 week number generation,
5510 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5511 numbers (which are not necessarily the same as calendar year numbers)
5514 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5516 The latest revisions from Paul Eggert are included, the usno1995
5517 file has been updated, and a new file ("WWW") covering useful URLs
5521 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5523 A simplification of a macro definition, a change to data for Sudan,
5524 and (for last minute shoppers) notes in the "Music" file on the CD
5528 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5530 (slightly reformatted) 8-bit-clean proposed patch
5532 minor patch: US/Eastern -> America/New_York
5534 snapshot of the USNO's latest data ("usno1995")
5536 some other minor cleanups
5539 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5540 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5544 support for 64-bit time_t's
5546 optimization in localtime.c
5549 Release code95e - 1995-10-13 13:23:57 -0400
5551 the mktime change to scan from future to past when trying to find time zone
5555 Release data95i - 1995-09-26 10:43:26 -0400
5557 For Canada/Central, guess that the Sun customer's "one week too
5558 early" was just a approximation, and the true error is one month
5559 too early. This is consistent with the rest of Canada.
5562 Release data95h - 1995-09-21 11:26:48 -0400
5564 latest changes from Paul Eggert
5567 Release code95d - 1995-09-14 11:14:45 -0400
5569 the addition of a "Music" file, which documents four recorded
5570 versions of the tune "Save That Time".
5573 Release data95g - 1995-09-01 17:21:36 -0400
5575 "yearistype" correction
5578 Release data95f - 1995-08-28 20:46:56 -0400
5580 Paul Eggert's change to the australasia file
5583 Release data95e - 1995-07-08 18:02:34 -0400
5585 The only change is a leap second at the end of this year.
5586 Thanks to Bradley White for forwarding news on the leap second.
5589 Release data95d - 1995-07-03 13:26:22 -0400
5591 Paul Eggert's changes
5594 Release data95c - 1995-07-02 19:19:28 -0400
5596 changes to "asia", "backward", "europe", and "southamerica"
5597 (read: northamericacentrics need not apply)
5600 Release code95c - 1995-03-13 14:00:46 -0500
5602 one-line fix for sign extension problems in detzcode
5605 Release 95b - 1995-03-04 11:22:38 -0500
5607 Minor changes in both:
5609 The "code" file contains a workaround for the lack of "unistd.h" in
5610 Microsoft C++ version 7.
5612 The "data" file contains a fixed "Link" for America/Shiprock.
5615 Release 94h - 1994-12-10 12:51:14 -0500
5619 * incorporate the changes to "zdump" and "date" to make changes to
5620 the "TZ" environment variable permanent;
5622 * incorporate the table changes by Paul Eggert;
5624 * include (and document) support for universal time specifications in
5625 data files - but do not (yet) include use of this feature in the
5628 Think of this as "TZ Classic" - the software has been set up not to break if
5629 universal time shows up in its input, and data entries have been
5630 left as is so as not to break existing implementations.
5633 Release data94f - 1994-08-20 12:56:09 -0400
5635 (with thanks!) the latest data updates from Paul Eggert
5638 Release data94e - 1994-06-04 13:13:53 -0400
5643 Release code94g - 1994-05-05 12:14:07 -0400
5645 fix missing "optind.c" and a reference to it in the Makefile
5648 Release code94f - 1994-05-05 13:00:33 -0000
5649 [tzcode94f.tar.gz is missing!]
5651 changes to avoid overflow in difftime, as well as changes to cope
5652 with the 52/53 challenge in strftime
5655 Release code94e - 1994-03-30 23:32:59 -0500
5657 change for the benefit of PCTS
5660 Release 94d - 1994-02-24 15:42:25 -0500
5662 Avoid clashes with POSIX semantics for zones such as GMT+4.
5664 Some other very minor housekeeping is also present.
5667 Release code94c - 1994-02-10 08:52:40 -0500
5669 Fix bug where mkdirs was broken unless you compile with
5670 -fwritable-strings (which is generally losing to do).
5673 Release 94b - 1994-02-07 10:04:33 -0500
5675 work by Paul Eggert who notes:
5677 I found another book of time zone histories by E W Whitman; it's not
5678 as extensive as Shanks but has a few goodies of its own. I used it
5679 to update the tables. I also fixed some more as a result of
5680 correspondence with Adam David and Peter Ilieve, and move some stray
5681 links from 'europe' to 'backward'. I corrected some scanning errors
5684 As far as the code goes, I fixed zic to allow years in the range
5685 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5686 And I cleaned up the zic documentation a little bit.
5689 Release data94a - 1994-02-03 08:58:54 -0500
5691 It simply incorporates the recently announced leap second into the
5695 Release 93g - 1993-11-22 17:28:27 -0500
5697 Paul Eggert has provided a good deal of historic information (based
5698 on Shanks), and there are some code changes to deal with the buglets
5699 that crawled out in dealing with the new information.
5702 Release 93f - 1993-10-15 12:27:46 -0400
5704 Paul Eggert's changes
5707 Release 93e - 1993-09-05 21:21:44 -0400
5709 This has updated data for Israel, England, and Kwajalein. There's
5710 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5711 Thanks to Paul Eggert and Peter Ilieve for the changes.
5714 Release 93d - 1993-06-17 23:34:17 -0400
5716 new fix and new data on Israel
5719 Release 93c - 1993-06-06 19:31:55 -0400
5724 Release 93b - 1993-02-02 14:53:58 -0500
5726 updated "leapseconds" file
5729 Release 93 - 1993-01-08 07:01:06 -0500
5731 At kre's suggestion, the package has been split in two - a code piece
5732 (which also includes documentation) that's only of use to folks who
5733 want to recompile things and a data piece useful to anyone who can
5736 The new version has a few changes to the data files, a few
5737 portability changes, and an off-by-one fix (with thanks to
5738 Tom Karzes at deshaw.com for providing a description and a
5742 Release 92c - 1992-11-21 17:35:36 -0000
5743 [tz92c.tar.Z is missing!]
5745 The fallout from the latest round of DST transitions.
5747 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5748 there's also a change to "zic.c" that makes it portable to more systems.
5751 Release 92 - 1992-04-25 18:17:03 -0000
5752 [tz92.tar.Z is missing!]
5754 By popular demand (well, at any rate, following a request by kre at munnari)
5757 The 1989 update of the time zone package featured:
5759 * POSIXization (including interpretation of POSIX-style TZ environment
5760 variables, provided by Guy Harris),
5761 * ANSIfication (including versions of "mktime" and "difftime"),
5762 * SVIDulation (an "altzone" variable)
5763 * MACHination (the "gtime" function)
5764 * corrections to some time zone data (including corrections to the rules
5765 for Great Britain and New Zealand)
5766 * reference data from the United States Naval Observatory for folks who
5767 want to do additional time zones
5768 * and the 1989 data for Saudi Arabia.
5770 (Since this code will be treated as "part of the implementation" in some
5771 places and as "part of the application" in others, there's no good way to
5772 name functions, such as timegm, that are not part of the proposed ANSI C
5773 standard; such functions have kept their old, underscore-free names in this
5776 And the "dysize" function has disappeared; it was present to allow
5777 compilation of the "date" command on old BSD systems, and a version of "date"
5778 is now provided in the package. The "date" command is not created when you
5779 "make all" since it may lack options provided by the version distributed with
5780 your operating system, or may not interact with the system in the same way
5781 the native version does.
5783 Since POSIX frowns on correct leap second handling, the default behavior of
5784 the "zic" command (in the absence of a "-L" option) has been changed to omit
5785 leap second information from its output files.
5791 This file contains copies of the part of each release announcement
5792 that talks about the changes in that release. The text has been
5793 adapted and reformatted for the purposes of this file.
5795 Traditionally a release R consists of a pair of tarball files,
5796 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5797 code2010a, data2012c) consist of just one or the other tarball, and a
5798 few (e.g., code2012c-data2012d) have tarballs with mixed version
5799 numbers. Recent releases also come in an experimental format
5800 consisting of a single tarball tzdb-R.tar.lz with extra data.
5802 Release timestamps are taken from the release's commit (for newer,
5803 Git-based releases), from the newest file in the tarball (for older
5804 releases, where this info is available) or from the email announcing
5805 the release (if all else fails; these are marked with a time zone
5806 abbreviation of -0000 and an "is missing!" comment).
5808 Earlier versions of the code and data were not announced on the tz
5809 list and are not summarized here.
5811 This file is in the public domain.