1 News for the tz database
3 Release 2023c - 2023-03-28 12:42:14 -0700
5 Changes to past and future timestamps
7 Model Lebanon's DST chaos by reverting data to tzdb 2023a.
8 (Thanks to Rany Hany for the heads-up.)
11 Release 2023b - 2023-03-23 19:50:38 -0700
13 Changes to future timestamps
15 This year Lebanon springs forward April 20/21 not March 25/26.
16 (Thanks to Saadallah Itani.) [This was reverted in 2023c.]
19 Release 2023a - 2023-03-22 12:39:33 -0700
22 Egypt now uses DST again, from April through October.
23 This year Morocco springs forward April 23, not April 30.
24 Palestine delays the start of DST this year.
25 Much of Greenland still uses DST from 2024 on.
26 America/Yellowknife now links to America/Edmonton.
27 tzselect can now use current time to help infer timezone.
28 The code now defaults to C99 or later.
29 Fix use of C23 attributes.
31 Changes to future timestamps
33 Starting in 2023, Egypt will observe DST from April's last Friday
34 through October's last Thursday. (Thanks to Ahmad ElDardiry.)
35 Assume the transition times are 00:00 and 24:00, respectively.
37 In 2023 Morocco's spring-forward transition after Ramadan
38 will occur April 23, not April 30. (Thanks to Milamber.)
39 Adjust predictions for future years accordingly. This affects
40 predictions for 2023, 2031, 2038, and later years.
42 This year Palestine will delay its spring forward from
43 March 25 to April 29 due to Ramadan. (Thanks to Heba Hamad.)
44 Make guesses for future Ramadans too.
46 Much of Greenland, represented by America/Nuuk, will continue to
47 observe DST using European Union rules. When combined with
48 Greenland's decision not to change the clocks in fall 2023,
49 America/Nuuk therefore changes from -03/-02 to -02/-01 effective
50 2023-10-29 at 01:00 UTC. (Thanks to Thomas M. Steenholdt.)
51 This change from 2022g doesn't affect timestamps until 2024-03-30,
52 and doesn't affect tm_isdst until 2023-03-25.
54 Changes to past timestamps
56 America/Yellowknife has changed from a Zone to a backward
57 compatibility Link, as it no longer differs from America/Edmonton
58 since 1970. (Thanks to Almaz Mingaleev.) This affects some
59 pre-1948 timestamps. The old data are now in 'backzone'.
61 Changes to past time zone abbreviations
63 When observing Moscow time, Europe/Kirov and Europe/Volgograd now
64 use the abbreviations MSK/MSD instead of numeric abbreviations,
65 for consistency with other timezones observing Moscow time.
69 You can now tell tzselect local time, to simplify later choices.
70 Select the 'time' option in its first prompt.
72 You can now compile with -DTZNAME_MAXIMUM=N to limit time zone
73 abbreviations to N bytes (default 255). The reference runtime
74 library now rejects POSIX-style TZ strings that contain longer
75 abbreviations, treating them as UTC. Previously the limit was
76 platform dependent and abbreviations were silently truncated to
77 16 bytes even when the limit was greater than 16.
79 The code by default is now designed for C99 or later. To build in
80 a C89 environment, compile with -DPORT_TO_C89. To support C89
81 callers of the tzcode library, compile with -DSUPPORT_C89. The
82 two new macros are transitional aids planned to be removed in a
83 future version, when C99 or later will be required.
85 The code now builds again on pre-C99 platforms, if you compile
86 with -DPORT_TO_C89. This fixes a bug introduced in 2022f.
88 On C23-compatible platforms tzcode no longer uses syntax like
89 'static [[noreturn]] void usage(void);'. Instead, it uses
90 '[[noreturn]] static void usage(void);' as strict C23 requires.
91 (Problem reported by Houge Langley.)
93 The code's functions now constrain their arguments with the C
94 'restrict' keyword consistently with their documentation.
95 This may allow future optimizations.
97 zdump again builds standalone with ckdadd and without setenv,
98 fixing a bug introduced in 2022g. (Problem reported by panic.)
100 leapseconds.awk can now process a leap seconds file that never
101 expires; this might be useful if leap seconds are discontinued.
103 Changes to commentary
105 tz-link.html has a new section "Coordinating with governments and
106 distributors". (Thanks to Neil Fuller for some of the text.)
108 To improve tzselect diagnostics, zone1970.tab's comments column is
109 now limited to countries that have multiple timezones.
111 Note that leap seconds are planned to be discontinued by 2035.
114 Release 2022g - 2022-11-29 08:58:31 -0800
117 The northern edge of Chihuahua changes to US timekeeping.
118 Much of Greenland stops changing clocks after March 2023.
119 Fix some pre-1996 timestamps in northern Canada.
120 C89 is now deprecated; please use C99 or later.
121 Portability fixes for AIX, libintl, MS-Windows, musl, z/OS
122 In C code, use more C23 features if available.
123 C23 timegm now supported by default
124 Fixes for unlikely integer overflows
126 Changes to future timestamps
128 In the Mexican state of Chihuahua, the border strip near the US
129 will change to agree with nearby US locations on 2022-11-30.
130 The strip's western part, represented by Ciudad Juárez, switches
131 from -06 all year to -07/-06 with US DST rules, like El Paso, TX.
132 The eastern part, represented by Ojinaga, will observe US DST next
133 year, like Presidio, TX. (Thanks to Heitor David Pinto.)
134 A new Zone America/Ciudad_Juarez splits from America/Ojinaga.
136 Much of Greenland, represented by America/Nuuk, stops observing
137 winter time after March 2023, so its daylight saving time becomes
138 standard time. (Thanks to Jonas Nyrup and Jürgen Appel.)
140 Changes to past timestamps
142 Changes for pre-1996 northern Canada (thanks to Chris Walton):
144 Merge America/Iqaluit and America/Pangnirtung into the former,
145 with a backward compatibility link for the latter name.
146 There is no good evidence the two locations differ since 1970.
147 This change affects pre-1996 America/Pangnirtung timestamps.
149 Cambridge Bay, Inuvik, Iqaluit, Rankin Inlet, Resolute and
150 Yellowknife did not observe DST in 1965, and did observe DST
151 from 1972 through 1979.
153 Whitehorse moved from -09 to -08 on 1966-02-27, not 1967-05-28.
155 Colombia's 1993 fallback was 02-06 24:00, not 04-04 00:00.
156 (Thanks to Alois Treindl.)
158 Singapore's 1981-12-31 change was at 16:00 UTC (23:30 local time),
159 not 24:00 local time. (Thanks to Geoff Clare via Robert Elz.)
163 Although tzcode still works with C89, bugs found in recent routine
164 maintenance indicate that bitrot has set in and that in practice
165 C89 is no longer used to build tzcode. As it is a maintenance
166 burden, support for C89 is planned to be removed soon. Instead,
167 please use compilers compatible with C99, C11, C17, or C23.
169 timegm, which tzcode implemented in 1989, will finally be
170 standardized 34 years later as part of C23, so timegm is now
171 supported even if STD_INSPIRED is not defined.
173 Fix bug in zdump's tzalloc emulation on hosts that lack tm_zone.
174 (Problem reported by Đoàn Trần Công Danh.)
176 Fix bug in zic on hosts where malloc(0) yields NULL on success.
177 (Problem reported by Tim McBrayer for AIX 6.1.)
179 Fix zic configuration to avoid linkage failures on some platforms.
180 (Problems reported by Gilmore Davidson and Igor Ivanov.)
182 Work around MS-Windows nmake incompatibility with POSIX.
183 (Problem reported by Manuela Friedrich.)
185 Port mktime and strftime to debugging platforms where accessing
186 uninitialized data has undefined behavior (strftime problem
187 reported by Robert Elz).
189 Check more carefully for unlikely integer overflows, preferring
190 C23 <stdckdint.h> to overflow checking by hand, as the latter has
193 Changes to build procedure
195 New Makefile rule check_mild that skips checking whether Link
196 lines are in the file 'backward'. (Inspired by a suggestion from
200 Release 2022f - 2022-10-28 18:04:57 -0700
203 Mexico will no longer observe DST except near the US border.
204 Chihuahua moves to year-round -06 on 2022-10-30.
205 Fiji no longer observes DST.
206 Move links to 'backward'.
207 In vanguard form, GMT is now a Zone and Etc/GMT a link.
208 zic now supports links to links, and vanguard form uses this.
209 Simplify four Ontario zones.
210 Fix a Y2438 bug when reading TZif data.
211 Enable 64-bit time_t on 32-bit glibc platforms.
212 Omit large-file support when no longer needed.
213 In C code, use some C23 features if available.
214 Remove no-longer-needed workaround for Qt bug 53071.
216 Changes to future timestamps
218 Mexico will no longer observe DST after 2022, except for areas
219 near the US border that continue to observe US DST rules.
220 On 2022-10-30 at 02:00 the Mexican state of Chihuahua moves
221 from -07 (-06 with DST) to year-round -06, thus not changing
222 its clocks that day. The new law states that Chihuahua
223 near the US border no longer observes US DST.
224 (Thanks to gera for the heads-up about Chihuahua.)
226 Fiji will not observe DST in 2022/3. (Thanks to Shalvin Narayan.)
227 For now, assume DST is suspended indefinitely.
231 Move links to 'backward' to ease and simplify link maintenance.
232 This affects generated data only if you use 'make BACKWARD='.
234 GMT is now a Zone and Etc/GMT a link instead of vice versa,
235 as GMT is needed for leap second support whereas Etc/GMT is not.
236 However, this change exposes a bug in TZUpdater 2.3.2 so it is
237 present only in vanguard form for now.
239 Vanguard form now uses links to links, as zic now supports this.
241 Changes to past timestamps
243 Simplify four Ontario zones, as most of the post-1970 differences
244 seem to have been imaginary. (Problem reported by Chris Walton.)
245 Move America/Nipigon, America/Rainy_River, and America/Thunder_Bay
246 to 'backzone'; backward-compatibility links still work, albeit
247 with some different timestamps before November 2005.
251 zic now supports links to links regardless of input line order.
252 For example, if Australia/Sydney is a Zone, the lines
253 Link Australia/Canberra Australia/ACT
254 Link Australia/Sydney Australia/Canberra
255 now work correctly, even though the shell commands
256 ln Australia/Canberra Australia/ACT
257 ln Australia/Sydney Australia/Canberra
258 would fail because the first command attempts to use a link
259 Australia/Canberra that does not exist until after the second
260 command is executed. Previously, zic had unspecified behavior if
261 a Link line's target was another link, and zic often misbehaved if
262 a Link line's target was a later Link line.
264 Fix line number in zic's diagnostic for a link to a link.
266 Fix a bug that caused localtime to mishandle timestamps starting
267 in the year 2438 when reading data generated by 'zic -b fat' when
268 distant-future DST transitions occur at times given in standard
269 time or in UT, not the usual case of local time. This occurs when
270 the corresponding .zi Rule lines specify DST transitions with TO
271 columns of 'max' and AT columns that end in 's' or 'u'. The
272 number 2438 comes from the 32-bit limit in the year 2038, plus the
273 400-year Gregorian cycle. (Problem reported by Bradley White.)
275 On glibc 2.34 and later, which optionally supports 64-bit time_t
276 on platforms like x86 where time_t was traditionally 32 bits,
277 default time_t to 64 instead of 32 bits. This lets functions like
278 localtime support timestamps after the year 2038, and fixes
279 year-2038 problems in zic when accessing files dated after 2038.
280 To continue to limit time_t to 32 bits on these platforms, use
281 "make CFLAGS='-D_TIME_BITS=32'".
283 In C code, do not enable large-file support on platforms like AIX
284 and macOS that no longer need it now that tzcode does not use
285 off_t or related functions like 'stat'. Large-file support is
286 still enabled by default on GNU/Linux, as it is needed for 64-bit
289 In C code, prefer C23 keywords to pre-C23 macros for alignof,
290 bool, false, and true. Also, use the following C23 features if
291 available: __has_include, unreachable.
293 zic no longer works around Qt bug 53071, as the relevant Qt
294 releases have been out of support since 2019. This change affects
295 only fat TZif files, as thin files never had the workaround.
297 zdump no longer modifies the environ vector when compiled on
298 platforms lacking tm_zone or when compiled with -DUSE_LTZ=0.
299 This avoid undefined behavior on POSIX platforms.
302 Release 2022e - 2022-10-11 11:13:02 -0700
305 Jordan and Syria switch from +02/+03 with DST to year-round +03.
307 Changes to future timestamps
309 Jordan and Syria are abandoning the DST regime and are changing to
310 permanent +03, so they will not fall back from +03 to +02 on
311 2022-10-28. (Thanks to Steffen Thorsen and Issam Al-Zuwairi.)
313 Changes to past timestamps
315 On 1922-01-01 Tijuana adopted standard time at 00:00, not 01:00.
317 Changes to past time zone abbreviations and DST flags
319 The temporary advancement of clocks in central Mexico in summer
320 1931 is now treated as daylight saving time, instead of as two
321 changes to standard time.
324 Release 2022d - 2022-09-23 12:02:57 -0700
327 Palestine transitions are now Saturdays at 02:00.
328 Simplify three Ukraine zones into one.
330 Changes to future timestamps
332 Palestine now springs forward and falls back at 02:00 on the
333 first Saturday on or after March 24 and October 24, respectively.
334 This means 2022 falls back 10-29 at 02:00, not 10-28 at 01:00.
335 (Thanks to Heba Hamad.)
337 Changes to past timestamps
339 Simplify three Ukraine zones to one, since the post-1970
340 differences seem to have been imaginary. Move Europe/Uzhgorod and
341 Europe/Zaporozhye to 'backzone'; backward-compatibility links
342 still work, albeit with different timestamps before October 1991.
345 Release 2022c - 2022-08-15 17:47:18 -0700
348 Work around awk bug in FreeBSD, macOS, etc.
349 Improve tzselect on intercontinental Zones.
353 Work around a bug in onetrueawk that broke commands like
354 'make traditional_tarballs' on FreeBSD, macOS, etc.
355 (Problem reported by Deborah Goldsmith.)
357 Add code to tzselect that uses experimental structured comments in
358 zone1970.tab to clarify whether Zones like Africa/Abidjan and
359 Europe/Istanbul cross continent or ocean boundaries.
360 (Inspired by a problem reported by Peter Krefting.)
362 Fix bug with 'zic -d /a/b/c' when /a is unwritable but the
363 directory /a/b already exists.
365 Remove zoneinfo2tdf.pl, as it was unused and triggered false
366 malware alarms on some email servers.
369 Release 2022b - 2022-08-10 15:38:32 -0700
372 Chile's DST is delayed by a week in September 2022.
373 Iran no longer observes DST after 2022.
374 Rename Europe/Kiev to Europe/Kyiv.
376 Vanguard form now uses %z.
377 Finish moving duplicate-since-1970 zones to 'backzone'.
378 New build option PACKRATLIST
379 New tailored_tarballs target, replacing rearguard_tarballs
381 Changes to future timestamps
383 Chile's 2022 DST start is delayed from September 4 to September 11.
384 (Thanks to Juan Correa.)
386 Iran plans to stop observing DST permanently, after it falls back
387 on 2022-09-21. (Thanks to Ali Mirjamali.)
389 Changes to past timestamps
391 Finish moving to 'backzone' the location-based zones whose
392 timestamps since 1970 are duplicates; adjust links accordingly.
393 This change ordinarily affects only pre-1970 timestamps, and with
394 the new PACKRATLIST option it does not affect any timestamps.
395 In this round the affected zones are Antarctica/Vostok,
396 Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik,
397 Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg,
398 Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas,
399 Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion,
400 Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei,
401 Pacific/Wake and Pacific/Wallis, and the affected links are
402 Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape,
403 Pacific/Truk, and Pacific/Yap.
405 From fall 1994 through fall 1995, Shanks wrote that Crimea's
406 DST transitions were at 02:00 standard time, not at 00:00.
407 (Thanks to Michael Deckers.)
409 Iran adopted standard time in 1935, not 1946. In 1977 it observed
410 DST from 03-21 23:00 to 10-20 24:00; its 1978 transitions were on
411 03-24 and 08-05, not 03-20 and 10-20; and its spring 1979
412 transition was on 05-27, not 03-21.
413 (Thanks to Roozbeh Pournader and Francis Santoni.)
415 Chile's observance of -04 from 1946-08-29 through 1947-03-31 was
416 considered DST, not standard time. Santiago and environs had moved
417 their clocks back to rejoin the rest of mainland Chile; put this
418 change at the end of 1946-08-28. (Thanks to Michael Deckers.)
420 Some old, small clock transitions have been removed, as people at
421 the time did not change their clocks. This affects Asia/Hong_Kong
422 in 1904, Asia/Ho_Chi_Minh in 1906, and Europe/Dublin in 1880.
426 Rename Europe/Kiev to Europe/Kyiv, as "Kyiv" is more common in
427 English now. Spelling of other names in Ukraine has not yet
428 demonstrably changed in common English practice so for now these
429 names retain old spellings, as in other countries (e.g.,
430 Europe/Prague not "Praha", and Europe/Sofia not "Sofiya").
434 zic has a new option '-R @N' to output explicit transitions < N.
435 (Need suggested by Almaz Mingaleev.)
437 'zic -r @N' no longer outputs bad data when N < first transition.
438 (Problem introduced in 2021d and reported by Peter Krefting.)
440 zic now checks its input for NUL bytes and unterminated lines, and
441 now supports input line lengths up to 2048 (not 512) bytes.
443 gmtime and related code now use the abbreviation "UTC" not "GMT".
444 POSIX is being revised to require this.
446 When tzset and related functions set vestigial static variables
447 like tzname, they now prefer specified timestamps to unspecified ones.
448 (Problem reported by Almaz Mingaleev.)
450 zic no longer complains "can't determine time zone abbreviation to
451 use just after until time" when a transition to a new standard
452 time occurs simultaneously with the first DST fallback transition.
454 Changes to build procedure
456 Source data in vanguard form now uses the %z notation, introduced
457 in release 2015f. For example, for America/Sao_Paulo vanguard
458 form contains the zone continuation line "-3:00 Brazil %z", which
459 is simpler and more reliable than the line "-3:00 Brazil -03/-02"
460 used in main and rearguard forms. The plan is for the main form
461 to use %z eventually; in the meantime maintainers of zi parsers
462 are encouraged to test the parsers on vanguard.zi.
464 The Makefile has a new PACKRATLIST option to select a subset of
465 'backzone'. For example, 'make PACKRATDATA=backzone
466 PACKRATLIST=zone.tab' now generates TZif files identical to those
467 of the global-tz project.
469 The Makefile has a new tailored_tarballs target for generating
470 special-purpose tarballs. It generalizes and replaces the
471 rearguard_tarballs target and related targets and macros, which
474 'make install' now defaults LOCALTIME to Factory not GMT,
475 which means the default abbreviation is now "-00" not "GMT".
477 Remove the posix_packrat target, marked obsolescent in 2016a.
480 Release 2022a - 2022-03-15 23:02:01 -0700
483 Palestine will spring forward on 2022-03-27, not -03-26.
484 zdump -v now outputs better failure indications.
485 Bug fixes for code that reads corrupted TZif data.
487 Changes to future timestamps
489 Palestine will spring forward on 2022-03-27, not 2022-03-26.
490 (Thanks to Heba Hamad.) Predict future transitions for first
491 Sunday >= March 25. Additionally, predict fallbacks to be the first
492 Friday on or after October 23, not October's last Friday, to be more
493 consistent with recent practice. The first differing fallback
494 prediction is on 2025-10-24, not 2025-10-31.
496 Changes to past timestamps
498 From 1992 through spring 1996, Ukraine's DST transitions were at
499 02:00 standard time, not at 01:00 UTC. (Thanks to Alois Treindl.)
501 Chile's Santiago Mean Time and its LMT precursor have been adjusted
502 eastward by 1 second to align with past and present law.
504 Changes to commentary
506 Add several references for Chile's 1946/1947 transitions, some of
507 which only affected portions of the country.
511 Fix bug when mktime gets confused by truncated TZif files with
512 unspecified local time. (Problem reported by Almaz Mingaleev.)
514 Fix bug when 32-bit time_t code reads malformed 64-bit TZif data.
515 (Problem reported by Christos Zoulas.)
517 When reading a version 2 or later TZif file, the TZif reader now
518 validates the version 1 header and data block only enough to skip
519 over them, as recommended by RFC 8536 section 4. Also, the TZif
520 reader no longer mistakenly attempts to parse a version 1 TZIf
521 file header as a TZ string.
523 zdump -v now outputs "(localtime failed)" and "(gmtime failed)"
524 when local time and UT cannot be determined for a timestamp.
526 Changes to build procedure
528 Distribution tarballs now use standard POSIX.1-1988 ustar format
529 instead of GNU format. Although the formats are almost identical
530 for these tarballs, ustar headers' magic fields contain "ustar"
531 instead of "ustar ", and their version fields contain "00" instead
532 of " ". The two formats are planned to diverge more significantly
533 for tzdb releases after 2242-03-16 12:56:31 UTC, when the ustar
534 format becomes obsolete and the tarballs switch to pax format, an
535 extension of ustar. For details about these formats, please see
536 "pax - portable archive interchange", IEEE Std 1003.1-2017,
537 <https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13>.
540 Release 2021e - 2021-10-21 18:41:00 -0700
542 Changes to future timestamps
544 Palestine will fall back 10-29 (not 10-30) at 01:00.
545 (Thanks to P Chan and Heba Hemad.)
548 Release 2021d - 2021-10-15 13:48:18 -0700
551 Fiji suspends DST for the 2021/2022 season.
552 'zic -r' marks unspecified timestamps with "-00".
554 Changes to future timestamps
556 Fiji will suspend observance of DST for the 2021/2022 season.
557 Assume for now that it will return next year. (Thanks to Jashneel
562 'zic -r' now uses "-00" time zone abbreviations for intervals
563 with UT offsets that are unspecified due to -r truncation.
564 This implements a change in draft Internet RFC 8536bis.
567 Release 2021c - 2021-10-01 14:21:49 -0700
570 Revert most 2021b changes to 'backward'.
571 Fix 'zic -b fat' bug in pre-1970 32-bit data.
572 Fix two Link line typos.
573 Distribute SECURITY file.
575 This release is intended as a bugfix release, to fix compatibility
576 problems and typos reported since 2021b was released.
578 Changes to Link directives
580 Revert almost all of 2021b's changes to the 'backward' file,
581 by moving Link directives back to where they were in 2021a.
582 Although 'zic' doesn't care which source file contains a Link
583 directive, some downstream uses ran into trouble with the move.
584 (Problem reported by Stephen Colebourne for Joda-Time.)
586 Fix typo that linked Atlantic/Jan_Mayen to the wrong location
587 (problem reported by Chris Walton).
589 Fix 'backzone' typo that linked America/Virgin to the wrong
590 location (problem reported by Michael Deckers).
594 Fix a bug in 'zic -b fat' that caused old timestamps to be
595 mishandled in 32-bit-only readers (problem reported by Daniel
598 Changes to documentation
600 Distribute the SECURITY file (problem reported by Andreas Radke).
603 Release 2021b - 2021-09-24 16:23:00 -0700
606 Jordan now starts DST on February's last Thursday.
607 Samoa no longer observes DST.
608 Merge more location-based Zones whose timestamps agree since 1970.
609 Move some backward-compatibility links to 'backward'.
610 Rename Pacific/Enderbury to Pacific/Kanton.
611 Correct many pre-1993 transitions in Malawi, Portugal, etc.
612 zic now creates each output file or link atomically.
613 zic -L no longer omits the POSIX TZ string in its output.
614 zic fixes for truncation and leap second table expiration.
615 zic now follows POSIX for TZ strings using all-year DST.
616 Fix some localtime crashes and bugs in obscure cases.
617 zdump -v now outputs more-useful boundary cases.
618 tzfile.5 better matches a draft successor to RFC 8536.
621 This release is prompted by recent announcements by Jordan and Samoa.
622 It incorporates many other changes that had accumulated since 2021a.
623 However, it omits most proposed changes that merged all Zones
624 agreeing since 1970, as concerns were raised about doing too many of
625 these changes at once. It does keeps some of these changes in the
626 interest of making tzdb more equitable one step at a time; see
627 "Merge more location-based Zones" below.
629 Changes to future timestamps
631 Jordan now starts DST on February's last Thursday.
632 (Thanks to Steffen Thorsen.)
634 Samoa no longer observes DST. (Thanks to Geoffrey D. Bennett.)
638 Rename Pacific/Enderbury to Pacific/Kanton. When we added
639 Enderbury in 1993, we did not know that it is uninhabited and that
640 Kanton (population two dozen) is the only inhabited location in
641 that timezone. The old name is now a backward-compatibility link.
643 Changes to past timestamps
645 Correct many pre-1993 transitions, fixing entries originally
646 derived from Shanks, Whitman, and Mundell. The fixes include:
647 - Barbados: standard time was introduced in 1911, not 1932; and
648 DST was observed in 1942-1944
649 - Cook Islands: In 1899 they switched from east to west of GMT,
650 celebrating Christmas for two days. They (and Niue) switched
651 to standard time in 1952, not 1901.
652 - Guyana: corrected LMT for Georgetown; the introduction of
653 standard time in 1911, not 1915; and corrections to 1975 and
655 - Kanton: uninhabited before 1937-08-31
656 - Niue: only observed -11:20 from 1952 through 1964, then went to
657 -11 instead of -11:30
658 - Portugal: DST was observed in 1950
659 - Tonga: corrected LMT; the introduction of standard time in 1945,
660 not 1901; and corrections to the transition from +12:20 to +13
662 Additional fixes to entries in the 'backzone' file include:
663 - Enderbury: inhabited only 1860/1885 and 1938-03-06/1942-02-09
664 - The Gambia: 1933 and 1942 transitions
665 - Malawi: several 1911 through 1925 transitions
666 - Sierra Leone: several 1913 through 1941 transitions, and DST
667 was NOT observed in 1957 through 1962
668 (Thanks to P Chan, Michael Deckers, Alexander Krivenyshev and
671 Merge more location-based Zones whose timestamps agree since 1970,
672 as pre-1970 timestamps are out of scope. This is part of a
673 process that has been ongoing since 2013. This does not affect
674 post-1970 timestamps, and timezone historians who build with 'make
675 PACKRATDATA=backzone' should see no changes to pre-1970 timestamps.
676 When merging, keep the most-populous location's data, and move
677 data for other locations to 'backzone' with a backward
678 link in 'backward'. For example, move America/Creston data to
679 'backzone' with a link in 'backward' from America/Phoenix because
680 the two timezones' timestamps agree since 1970; this change
681 affects some pre-1968 timestamps in America/Creston because
682 Creston and Phoenix disagreed before 1968. The affected Zones
683 are Africa/Accra, America/Atikokan, America/Blanc-Sablon,
684 America/Creston, America/Curacao, America/Nassau,
685 America/Port_of_Spain, Antarctica/DumontDUrville, and
688 Changes to maintenance procedure
690 The new file SECURITY covers how to report security-related bugs.
692 Several backward-compatibility links have been moved to the
693 'backward' file. These links, which range from Africa/Addis_Ababa
694 to Pacific/Saipan, are only for compatibility with now-obsolete
695 guidelines suggesting an entry for every ISO 3166 code.
696 The intercontinental convenience links Asia/Istanbul and
697 Europe/Nicosia have also been moved to 'backward'.
701 zic now creates each output file or link atomically,
702 possibly by creating a temporary file and then renaming it.
703 This avoids races where a TZ setting would temporarily stop
704 working while zic was installing a replacement file or link.
706 zic -L no longer omits the POSIX TZ string in its output.
707 Starting with 2020a, zic -L truncated its output according to the
708 "Expires" directive or "#expires" comment in the leapseconds file.
709 The resulting TZif files omitted daylight saving transitions after
710 the leap second table expired, which led to far less accurate
711 predictions of times after the expiry. Although future timestamps
712 cannot be converted accurately in the presence of leap seconds, it
713 is more accurate to convert near-future timestamps with a few
714 seconds error than with an hour error, so zic -L no longer
715 truncates output in this way.
717 Instead, when zic -L is given the "Expires" directive, it now
718 outputs the expiration by appending a no-change entry to the leap
719 second table. Although this should work well with most TZif
720 readers, it does not conform to Internet RFC 8536 and some pickier
721 clients (including tzdb 2017c through 2021a) reject it, so
722 "Expires" directives are currently disabled by default. To enable
723 them, set the EXPIRES_LINE Makefile variable. If a TZif file uses
724 this new feature it is marked with a new TZif version number 4,
725 a format intended to be documented in a successor to RFC 8536.
727 zic -L LEAPFILE -r @LO no longer generates an invalid TZif file
728 that omits leap second information for the range LO..B when LO
729 falls between two leap seconds A and B. Instead, it generates a
730 TZif version 4 file that represents the previously missing
733 The TZif reader now allows the leap second table to begin with a
734 correction other than -1 or +1, and to contain adjacent
735 transitions with equal corrections. This supports TZif version 4.
737 The TZif reader now lets leap seconds occur less than 28 days
738 apart. This supports possible future TZif extensions.
740 Fix bug that caused 'localtime' etc. to crash when TZ was
741 set to a all-year DST string like "EST5EDT4,0/0,J365/25" that does
742 not conform to POSIX but does conform to Internet RFC 8536.
744 Fix another bug that caused 'localtime' etc. to crash when TZ was
745 set to a POSIX-conforming but unusual TZ string like
746 "EST5EDT4,0/0,J365/0", where almost all the year is DST.
748 Fix yet another bug that caused 'localtime' etc. to mishandle slim
749 TZif files containing leap seconds after the last explicit
750 transition in the table, or when handling far-future timestamps
751 in slim TZif files lacking leap seconds.
753 Fix localtime misbehavior involving positive leap seconds.
754 This change affects only behavior for "right" system time,
755 which contains leap seconds, and only if the UT offset is
756 not a multiple of 60 seconds when a positive leap second occurs.
757 (No such timezone exists in tzdb, luckily.) Without the fix,
758 the timestamp was ambiguous during a positive leap second.
759 With the fix, any seconds occurring after a positive leap second
760 and within the same localtime minute are counted through 60, not
761 through 59; their UT offset (tm_gmtoff) is the same as before.
762 Here is how the fix affects timestamps in a timezone with UT
763 offset +01:23:45 (5025 seconds) and with a positive leap second at
764 1972-06-30 23:59:60 UTC (78796800):
766 time_t without the fix with the fix
767 78796800 1972-07-01 01:23:45 1972-07-01 01:23:45 (leap second)
768 78796801 1972-07-01 01:23:45 1972-07-01 01:23:46
770 78796815 1972-07-01 01:23:59 1972-07-01 01:23:60
771 78796816 1972-07-01 01:24:00 1972-07-01 01:24:00
773 Fix an unlikely bug that caused 'localtime' etc. to misbehave if
774 civil time changes a few seconds before time_t wraps around, when
775 leap seconds are enabled.
777 Fix bug in zic -r; in some cases, the dummy time type after the
778 last time transition disagreed with the TZ string, contrary to
779 Internet RFC 8563 section 3.3.
781 Fix a bug with 'zic -r @X' when X is a negative leap second that
782 has a nonnegative correction. Without the fix, the output file
783 was truncated so that X appeared to be a positive leap second.
784 Fix a similar, even less likely bug when truncating at a positive
785 leap second that has a nonpositive correction.
787 zic -r now reports an error if given rolling leap seconds, as this
788 usage has never generally worked and is evidently unused.
790 zic now generates a POSIX-conforming TZ string for TZif files
791 where all-year DST is predicted for the indefinite future.
792 For example, for all-year Eastern Daylight Time, zic now generates
793 "XXX3EDT4,0/0,J365/23" where it previously generated
794 "EST5EDT,0/0,J365/25" or "". (Thanks to Michael Deckers for
795 noting the possibility of POSIX conformance.)
797 zic.c no longer requires sys/wait.h (thanks to spazmodius for
798 noting it wasn't needed).
800 When reading slim TZif files, zdump no longer mishandles leap
801 seconds on the rare platforms where time_t counts leap seconds,
802 fixing a bug introduced in 2014g.
804 zdump -v now outputs timestamps at boundaries of what localtime
805 and gmtime can represent, instead of the less useful timestamps
806 one day after the minimum and one day before the maximum.
807 (Thanks to Arthur David Olson for prototype code, and to Manuela
808 Friedrich for debugging help.)
810 zdump's -c and -t options are now consistently inclusive for the
811 lower time bound and exclusive for the upper. Formerly they were
812 inconsistent. (Confusion noted by Martin Burnicki.)
814 Changes to build procedure
816 You can now compile with -DHAVE_MALLOC_ERRNO=0 to port to
817 non-POSIX hosts where malloc doesn't set errno.
818 (Problem reported by Jan Engelhardt.)
820 Changes to documentation
822 tzfile.5 better matches a draft successor to RFC 8536
823 <https://datatracker.ietf.org/doc/draft-murchison-rfc8536bis/01/>.
826 Release 2021a - 2021-01-24 10:54:57 -0800
828 Changes to future timestamps
830 South Sudan changes from +03 to +02 on 2021-02-01 at 00:00.
831 (Thanks to Steffen Thorsen.)
834 Release 2020f - 2020-12-29 00:17:46 -0800
836 Change to build procedure
838 'make rearguard_tarballs' no longer generates a bad rearguard.zi,
839 fixing a 2020e bug. (Problem reported by Deborah Goldsmith.)
842 Release 2020e - 2020-12-22 15:14:34 -0800
845 Volgograd switches to Moscow time on 2020-12-27 at 02:00.
847 Changes to future timestamps
849 Volgograd changes time zone from +04 to +03 on 2020-12-27 at 02:00.
850 (Thanks to Alexander Krivenyshev and Stepan Golosunov.)
852 Changes to past timestamps
854 Correct many pre-1986 transitions, fixing entries originally
855 derived from Shanks. The fixes include:
856 - Australia: several 1917 through 1971 transitions
857 - The Bahamas: several 1941 through 1945 transitions
858 - Bermuda: several 1917 through 1956 transitions
859 - Belize: several 1942 through 1968 transitions
860 - Ghana: several 1915 through 1956 transitions
861 - Israel and Palestine: several 1940 through 1985 transitions
862 - Kenya and adjacent: several 1908 through 1960 transitions
863 - Nigeria and adjacent: correcting LMT in Lagos, and several 1905
864 through 1919 transitions
865 - Seychelles: the introduction of standard time in 1907, not 1906
866 - Vanuatu: DST in 1973-1974, and a corrected 1984 transition
869 Because of the Australia change, Australia/Currie (King Island) is
870 no longer needed, as it is identical to Australia/Hobart for all
871 timestamps since 1970 and was therefore created by mistake.
872 Australia/Currie has been moved to the 'backward' file and its
873 corrected data moved to the 'backzone' file.
875 Changes to past time zone abbreviations and DST flags
877 To better match legislation in Turks and Caicos, the 2015 shift to
878 year-round observance of -04 is now modeled as AST throughout before
879 returning to Eastern Time with US DST in 2018, rather than as
880 maintaining EDT until 2015-11-01. (Thanks to P Chan.)
882 Changes to documentation
884 The zic man page now documents zic's coalescing of transitions
885 when a zone falls back just before DST springs forward.
888 Release 2020d - 2020-10-21 11:24:13 -0700
891 Palestine ends DST earlier than predicted, on 2020-10-24.
893 Changes to past and future timestamps
895 Palestine ends DST on 2020-10-24 at 01:00, instead of 2020-10-31
896 as previously predicted (thanks to Sharef Mustafa.) Its
897 2019-10-26 fall-back was at 00:00, not 01:00 (thanks to Steffen
898 Thorsen.) Its 2015-10-23 transition was at 01:00 not 00:00, and
899 its spring 2020 transition was on March 28 at 00:00, not March 27
900 (thanks to Pierre Cashon.) This affects Asia/Gaza and
901 Asia/Hebron. Assume future spring and fall transitions will be on
902 the Saturday preceding the last Sunday of March and October,
906 Release 2020c - 2020-10-16 11:15:53 -0700
909 Fiji starts DST later than usual, on 2020-12-20.
911 Changes to future timestamps
913 Fiji will start DST on 2020-12-20, instead of 2020-11-08 as
914 previously predicted. DST will still end on 2021-01-17.
915 (Thanks to Raymond Kumar and Alan Mintz.) Assume for now that
916 the later-than-usual start date is a one-time departure from the
919 Changes to build procedure
921 Rearguard tarballs now contain an empty file pacificnew.
922 Some older downstream software expects this file to exist.
923 (Problem reported by Mike Cullinan.)
926 Release 2020b - 2020-10-06 18:35:04 -0700
929 Revised predictions for Morocco's changes starting in 2023.
930 Canada's Yukon changes to -07 on 2020-11-01, not 2020-03-08.
931 Macquarie Island has stayed in sync with Tasmania since 2011.
932 Casey, Antarctica is at +08 in winter and +11 in summer.
933 zic no longer supports -y, nor the TYPE field of Rules.
935 Changes to future timestamps
937 Morocco's spring-forward after Ramadan is now predicted to occur
938 no sooner than two days after Ramadan, instead of one day.
939 (Thanks to Milamber.) The first altered prediction is for 2023,
940 now predicted to spring-forward on April 30 instead of April 23.
942 Changes to past and future timestamps
944 Casey Station, Antarctica has been using +08 in winter and +11 in
945 summer since 2018. The most recent transition from +08 to +11 was
946 2020-10-04 00:01. Also, Macquarie Island has been staying in
947 sync with Tasmania since 2011. (Thanks to Steffen Thorsen.)
949 Changes to past and future time zone abbreviations and DST flags
951 Canada's Yukon, represented by America/Whitehorse and
952 America/Dawson, changes its time zone rules from -08/-07 to
953 permanent -07 on 2020-11-01, not on 2020-03-08 as 2020a had it.
954 This change affects only the time zone abbreviation (MST vs PDT)
955 and daylight saving flag for the period between the two dates.
956 (Thanks to Andrew G. Smith.)
958 Changes to past timestamps
960 Correct several transitions for Hungary for 1918/1983.
961 For example, the 1983-09-25 fall-back was at 01:00, not 03:00.
962 (Thanks to Géza Nyáry.) Also, the 1890 transition to standard
963 time was on 11-01, not 10-01 (thanks to Michael Deckers).
965 The 1891 French transition was on March 16, not March 15. The
966 1911-03-11 French transition was at midnight, not a minute later.
967 Monaco's transitions were on 1892-06-01 and 1911-03-29, not
968 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
972 Support for zic's long-obsolete '-y YEARISTYPE' option has been
973 removed and, with it, so has support for the TYPE field in Rule
974 lines, which is now reserved for compatibility with earlier zic.
975 These features were previously deprecated in release 2015f.
976 (Thanks to Tim Parenti.)
978 zic now defaults to '-b slim' instead of to '-b fat'.
980 zic's new '-l -' and '-p -' options uninstall any existing
981 localtime and posixrules files, respectively.
983 The undocumented and ineffective tzsetwall function has been
986 Changes to build procedure
988 The Makefile now defaults POSIXRULES to '-', so the posixrules
989 feature (obsolete as of 2019b) is no longer installed by default.
991 Changes to documentation and commentary
993 The long-obsolete files pacificnew, systemv, and yearistype.sh have
994 been removed from the distribution. (Thanks to Tim Parenti.)
997 Release 2020a - 2020-04-23 16:03:47 -0700
1000 Morocco springs forward on 2020-05-31, not 2020-05-24.
1001 Canada's Yukon advanced to -07 year-round on 2020-03-08.
1002 America/Nuuk renamed from America/Godthab.
1003 zic now supports expiration dates for leap second lists.
1005 Changes to future timestamps
1007 Morocco's second spring-forward transition in 2020 will be May 31,
1008 not May 24 as predicted earlier. (Thanks to Semlali Naoufal.)
1009 Adjust future-year predictions to use the first Sunday after the
1010 day after Ramadan, not the first Sunday after Ramadan.
1012 Canada's Yukon, represented by America/Whitehorse and
1013 America/Dawson, advanced to -07 year-round, beginning with its
1014 spring-forward transition on 2020-03-08, and will not fall back on
1015 2020-11-01. Although a government press release calls this
1016 "permanent Pacific Daylight Saving Time", we prefer MST for
1017 consistency with nearby Dawson Creek, Creston, and Fort Nelson.
1018 (Thanks to Tim Parenti.)
1020 Changes to past timestamps
1022 Shanghai observed DST in 1919. (Thanks to Phake Nick.)
1024 Changes to timezone identifiers
1026 To reflect current usage in English better, America/Godthab has
1027 been renamed to America/Nuuk. A backwards-compatibility link
1028 remains for the old name.
1032 localtime.c no longer mishandles timestamps after the last
1033 transition in a TZif file with leap seconds and with daylight
1034 saving time transitions projected into the indefinite future.
1035 For example, with TZ='America/Los_Angeles' with leap seconds,
1036 zdump formerly reported a DST transition on 2038-03-14
1037 from 01:59:32.999... to 02:59:33 instead of the correct transition
1038 from 01:59:59.999... to 03:00:00.
1040 zic -L now supports an Expires line in the leapseconds file, and
1041 truncates the TZif output accordingly. This propagates leap
1042 second expiration information into the TZif file, and avoids the
1043 abovementioned localtime.c bug as well as similar bugs present in
1044 many client implementations. If no Expires line is present, zic
1045 -L instead truncates the TZif output based on the #expires comment
1046 present in leapseconds files distributed by tzdb 2018f and later;
1047 however, this usage is obsolescent. For now, the distributed
1048 leapseconds file has an Expires line that is commented out, so
1049 that the file can be fed to older versions of zic which ignore the
1050 commented-out line. Future tzdb distributions are planned to
1051 contain a leapseconds file with an Expires line.
1053 The configuration macros HAVE_TZNAME and USG_COMPAT should now be
1054 set to 1 if the system library supports the feature, and 2 if not.
1055 As before, these macros are nonzero if tzcode should support the
1056 feature, zero otherwise.
1058 The configuration macro ALTZONE now has the same values with the
1059 same meaning as HAVE_TZNAME and USG_COMPAT.
1061 The code's defense against CRLF in leap-seconds.list is now
1062 portable to POSIX awk. (Problem reported by Deborah Goldsmith.)
1064 Although the undocumented tzsetwall function is not changed in
1065 this release, it is now deprecated in preparation for removal in
1066 future releases. Due to POSIX requirements, tzsetwall has not
1067 worked for some time. Any code that uses it should instead use
1068 tzalloc(NULL) or, if portability trumps thread-safety, should
1069 unset the TZ environment variable.
1071 Changes to commentary
1073 The Îles-de-la-Madeleine and the Listuguj reserve are noted as
1074 following America/Halifax, and comments about Yukon's "south" and
1075 "north" have been corrected to say "east" and "west". (Thanks to
1079 Release 2019c - 2019-09-11 08:59:48 -0700
1082 Fiji observes DST from 2019-11-10 to 2020-01-12.
1083 Norfolk Island starts observing Australian-style DST.
1085 Changes to future timestamps
1087 Fiji's next DST transitions will be 2019-11-10 and 2020-01-12
1088 instead of 2019-11-03 and 2020-01-19. (Thanks to Raymond Kumar.)
1089 Adjust future guesses accordingly.
1091 Norfolk Island will observe Australian-style DST starting in
1092 spring 2019. The first transition is on 2019-10-06. (Thanks to
1093 Kyle Czech and Michael Deckers.)
1095 Changes to past timestamps
1097 Many corrections to time in Turkey from 1940 through 1985.
1098 (Thanks to Oya Vulaş via Alois Treindl, and to Kıvanç Yazan.)
1100 The Norfolk Island 1975-03-02 transition was at 02:00 standard
1101 time, not 02:00 DST. (Thanks to Michael Deckers.)
1103 South Korea observed DST from 1948 through 1951. Although this
1104 info was supposed to appear in release 2014j, a typo inadvertently
1105 suppressed the change. (Thanks to Alois Treindl.)
1107 Detroit observed DST in 1967 and 1968 following the US DST rules,
1108 except that its 1967 DST began on June 14 at 00:01. (Thanks to
1109 Alois Treindl for pointing out that the old data entries were
1112 Fix several errors in pre-1970 transitions in Perry County, IN.
1113 (Thanks to Alois Treindl for pointing out the 1967/9 errors.)
1115 Edmonton did not observe DST in 1967 or 1969. In 1946 Vancouver
1116 ended DST on 09-29 not 10-13, and Vienna ended DST on 10-07 not
1117 10-06. In 1945 Königsberg (now Kaliningrad) switched from +01/+02
1118 to +02/+03 on 04-10 not 01-01, and its +02/+03 is abbreviated
1119 EET/EEST, not CET/CEST. (Thanks to Alois Treindl.) In 1946
1120 Königsberg switched to +03 on 04-07 not 01-01.
1122 In 1946 Louisville switched from CST to CDT on 04-28 at 00:01, not
1123 01-01 at 00:00. (Thanks to Alois Treindl and Michael Deckers.)
1124 Also, it switched from CST to CDT on 1950-04-30, not 1947-04-27.
1126 The 1892-05-01 transition in Brussels was at 00:17:30, not at noon.
1127 (Thanks to Michael Deckers.)
1129 Changes to past time zone abbreviations and DST flags
1131 Hong Kong Winter Time, observed from 1941-10-01 to 1941-12-25,
1132 is now flagged as DST and is abbreviated HKWT not HKT.
1136 leapseconds.awk now relies only on its input data, rather than
1137 also relying on its comments. (Inspired by code from Dennis
1138 Ferguson and Chris Woodbury.)
1140 The code now defends against CRLFs in leap-seconds.list.
1141 (Thanks to Brian Inglis and Chris Woodbury.)
1143 Changes to documentation and commentary
1145 theory.html discusses leap seconds. (Thanks to Steve Summit.)
1147 Nashville's newspapers dueled about the time of day in the 1950s.
1148 (Thanks to John Seigenthaler.)
1150 Liechtenstein observed Swiss DST in 1941/2.
1151 (Thanks to Alois Treindl.)
1154 Release 2019b - 2019-07-01 00:09:53 -0700
1157 Brazil no longer observes DST.
1158 'zic -b slim' outputs smaller TZif files; please try it out.
1159 Palestine's 2019 spring-forward transition was on 03-29, not 03-30.
1161 Changes to future timestamps
1163 Brazil has canceled DST and will stay on standard time indefinitely.
1164 (Thanks to Steffen Thorsen, Marcus Diniz, and Daniel Soares de
1167 Predictions for Morocco now go through 2087 instead of 2037, to
1168 work around a problem on newlib when using TZif files output by
1169 zic 2019a or earlier. (Problem reported by David Gauchard.)
1171 Changes to past and future timestamps
1173 Palestine's 2019 spring transition was 03-29 at 00:00, not 03-30
1174 at 01:00. (Thanks to Sharef Mustafa and Even Scharning.) Guess
1175 future transitions to be March's last Friday at 00:00.
1177 Changes to past timestamps
1179 Hong Kong's 1941-06-15 spring-forward transition was at 03:00, not
1180 03:30. Its 1945 transition from JST to HKT was on 11-18 at 02:00,
1181 not 09-15 at 00:00. In 1946 its spring-forward transition was on
1182 04-21 at 00:00, not the previous day at 03:30. From 1946 through
1183 1952 its fall-back transitions occurred at 04:30, not at 03:30.
1184 In 1947 its fall-back transition was on 11-30, not 12-30.
1187 Changes to past time zone abbreviations
1189 Italy's 1866 transition to Rome Mean Time was on December 12, not
1190 September 22. This affects only the time zone abbreviation for
1191 Europe/Rome between those dates. (Thanks to Stephen Trainor and
1194 Changes affecting metadata only
1196 Add info about the Crimea situation in zone1970.tab and zone.tab.
1197 (Problem reported by Serhii Demediuk.)
1201 zic's new -b option supports a way to control data bloat and to
1202 test for year-2038 bugs in software that reads TZif files.
1203 'zic -b fat' and 'zic -b slim' generate larger and smaller output;
1204 for example, changing from fat to slim shrinks the Europe/London
1205 file from 3648 to 1599 bytes, saving about 56%. Fat and slim
1206 files represent the same set of timestamps and use the same TZif
1207 format as documented in tzfile(5) and in Internet RFC 8536.
1208 Fat format attempts to work around bugs or incompatibilities in
1209 older software, notably software that mishandles 64-bit TZif data
1210 or uses obsolete TZ strings like "EET-2EEST" that lack DST rules.
1211 Slim format is more efficient and does not work around 64-bit bugs
1212 or obsolete TZ strings. Currently zic defaults to fat format
1213 unless you compile with -DZIC_BLOAT_DEFAULT=\"slim\"; this
1214 out-of-the-box default is intended to change in future releases
1215 as the buggy software often mishandles timestamps anyway.
1217 zic no longer treats a set of rules ending in 2037 specially.
1218 Previously, zic assumed that such a ruleset meant that future
1219 timestamps could not be predicted, and therefore omitted a
1220 POSIX-like TZ string in the TZif output. The old behavior is no
1221 longer needed for current tzdata, and caused problems with newlib
1222 when used with older tzdata (reported by David Gauchard).
1224 zic no longer generates some artifact transitions. For example,
1225 Europe/London no longer has a no-op transition in January 1996.
1227 Changes to build procedure
1229 tzdata.zi now assumes zic 2017c or later. This shrinks tzdata.zi
1232 Changes to documentation and commentary
1234 The Makefile now documents the POSIXRULES macro as being obsolete,
1235 and similarly, zic's -p POSIXRULES option is now documented as
1236 being obsolete. Although the POSIXRULES feature still exists and
1237 works as before, in practice it is rarely used for its intended
1238 purpose, and it does not work either in the default reference
1239 implementation (for timestamps after 2037) or in common
1240 implementations such as GNU/Linux (for contemporary timestamps).
1241 Since POSIXRULES was designed primarily as a temporary transition
1242 facility for System V platforms that died off decades ago, it is
1243 being decommissioned rather than institutionalized.
1245 New info on Bonin Islands and Marcus (thanks to Wakaba and Phake Nick).
1248 Release 2019a - 2019-03-25 22:01:33 -0700
1251 Palestine "springs forward" on 2019-03-30 instead of 2019-03-23.
1252 Metlakatla "fell back" to rejoin Alaska Time on 2019-01-20 at 02:00.
1254 Changes to past and future timestamps
1256 Palestine will not start DST until 2019-03-30, instead of 2019-03-23 as
1257 previously predicted. Adjust our prediction by guessing that spring
1258 transitions will be between 24 and 30 March, which matches recent practice
1259 since 2016. (Thanks to Even Scharning and Tim Parenti.)
1261 Metlakatla ended its observance of Pacific standard time,
1262 rejoining Alaska Time, on 2019-01-20 at 02:00. (Thanks to Ryan
1263 Stanley and Tim Parenti.)
1265 Changes to past timestamps
1267 Israel observed DST in 1980 (08-02/09-13) and 1984 (05-05/08-25).
1268 (Thanks to Alois Treindl and Isaac Starkman.)
1270 Changes to time zone abbreviations
1272 Etc/UCT is now a backward-compatibility link to Etc/UTC, instead
1273 of being a separate zone that generates the abbreviation "UCT",
1274 which nowadays is typically a typo. (Problem reported by Isiah
1279 zic now has an -r option to limit the time range of output data.
1280 For example, 'zic -r @1000000000' limits the output data to
1281 timestamps starting 1000000000 seconds after the Epoch.
1282 This helps shrink output size and can be useful for applications
1283 not needing the full timestamp history, such as TZDIST truncation;
1284 see Internet RFC 8536 section 5.1. (Inspired by a feature request
1285 from Christopher Wong, helped along by bug reports from Wong and
1288 Changes to documentation
1290 Mention Internet RFC 8536 (February 2019), which documents TZif.
1292 tz-link.html now cites tzdata-meta
1293 <https://tzdata-meta.timtimeonline.com/>.
1296 Release 2018i - 2018-12-30 11:05:43 -0800
1299 São Tomé and Príncipe switches from +01 to +00 on 2019-01-01.
1301 Changes to future timestamps
1303 Due to a change in government, São Tomé and Príncipe switches back
1304 from +01 to +00 on 2019-01-01 at 02:00. (Thanks to Vadim
1305 Nasardinov and Michael Deckers.)
1308 Release 2018h - 2018-12-23 17:59:32 -0800
1311 Qyzylorda, Kazakhstan moved from +06 to +05 on 2018-12-21.
1312 New zone Asia/Qostanay because Qostanay, Kazakhstan didn't move.
1313 Metlakatla, Alaska observes PST this winter only.
1314 Guess Morocco will continue to adjust clocks around Ramadan.
1315 Add predictions for Iran from 2038 through 2090.
1317 Changes to future timestamps
1319 Guess that Morocco will continue to fall back just before and
1320 spring forward just after Ramadan, the practice since 2012.
1321 (Thanks to Maamar Abdelkader.) This means Morocco will observe
1322 negative DST during Ramadan in main and vanguard formats, and in
1323 rearguard format it stays in the +00 timezone and observes
1324 ordinary DST in all months other than Ramadan. As before, extend
1325 this guesswork to the year 2037. As a consequence, Morocco is
1326 scheduled to observe three DST transitions in some Gregorian years
1327 (e.g., 2033) due to the mismatch between the Gregorian and Islamic
1330 The table of exact transitions for Iranian DST has been extended.
1331 It formerly cut off before the year 2038 in a nod to 32-bit time_t.
1332 It now cuts off before 2091 as there is doubt about how the Persian
1333 calendar will treat 2091. This change predicts DST transitions in
1334 2038-9, 2042-3, and 2046-7 to occur one day later than previously
1335 predicted. As before, post-cutoff transitions are approximated.
1337 Changes to past and future timestamps
1339 Qyzylorda (aka Kyzylorda) oblast in Kazakhstan moved from +06 to
1340 +05 on 2018-12-21. This is a zone split as Qostanay (aka
1341 Kostanay) did not switch, so create a zone Asia/Qostanay.
1343 Metlakatla moved from Alaska to Pacific standard time on 2018-11-04.
1344 It did not change clocks that day and remains on -08 this winter.
1345 (Thanks to Ryan Stanley.) It will revert to the usual Alaska
1346 rules next spring, so this change affects only timestamps
1347 from 2018-11-04 through 2019-03-10.
1349 Change to past timestamps
1351 Kwajalein's 1993-08-20 transition from -12 to +12 was at 24:00,
1352 not 00:00. I transcribed the time incorrectly from Shanks.
1353 (Thanks to Phake Nick.)
1355 Nauru's 1979 transition was on 02-10 at 02:00, not 05-01 at 00:00.
1356 (Thanks to Phake Nick.)
1358 Guam observed DST irregularly from 1959 through 1977.
1359 (Thanks to Phake Nick.)
1361 Hong Kong observed DST in 1941 starting 06-15 (not 04-01), then on
1362 10-01 changed standard time to +08:30 (not +08). Its transition
1363 back to +08 after WWII was on 1945-09-15, not the previous day.
1364 Its 1904-10-30 change took effect at 01:00 +08 (not 00:00 LMT).
1365 (Thanks to Phake Nick, Steve Allen, and Joseph Myers.) Also,
1366 its 1952 fallback was on 11-02 (not 10-25).
1368 This release contains many changes to timestamps before 1946 due
1369 to Japanese possession or occupation of Pacific/Chuuk,
1370 Pacific/Guam, Pacific/Kosrae, Pacific/Kwajalein, Pacific/Majuro,
1371 Pacific/Nauru, Pacific/Palau, and Pacific/Pohnpei.
1372 (Thanks to Phake Nick.)
1374 Assume that the Spanish East Indies was like the Philippines and
1375 observed American time until the end of 1844. This affects
1376 Pacific/Chuuk, Pacific/Kosrae, Pacific/Palau, and Pacific/Pohnpei.
1378 Changes to past tm_isdst flags
1380 For the recent Morocco change, the tm_isdst flag should be 1 from
1381 2018-10-27 00:00 to 2018-10-28 03:00. (Thanks to Michael Deckers.)
1382 Give a URL to the official decree. (Thanks to Matt Johnson.)
1385 Release 2018g - 2018-10-26 22:22:45 -0700
1388 Morocco switches to permanent +01 on 2018-10-28.
1390 Changes to future timestamps
1392 Morocco switches from +00/+01 to permanent +01 effective 2018-10-28,
1393 so its clocks will not fall back as previously scheduled.
1394 (Thanks to Mohamed Essedik Najd and Brian Inglis.)
1398 When generating TZif files with leap seconds, zic no longer uses a
1399 format that trips up older 32-bit clients, fixing a bug introduced
1400 in 2018f. (Reported by Daniel Fischer.) Also, the zic workaround
1401 for QTBUG-53071 now also works for TZif files with leap seconds.
1403 The translator to rearguard format now rewrites the line
1404 "Rule Japan 1948 1951 - Sep Sat>=8 25:00 0 S" to
1405 "Rule Japan 1948 1951 - Sep Sun>=9 1:00 0 S".
1406 This caters to zic before 2007 and to Oracle TZUpdater 2.2.0
1407 and earlier. (Reported by Christos Zoulas.)
1409 Changes to past time zone abbreviations
1411 Change HDT to HWT/HPT for WWII-era abbreviations in Hawaii.
1412 This reverts to 2011h, as the abbreviation change in 2011i was
1415 Changes to documentation
1417 tzfile.5 has new sections on interoperability issues.
1420 Release 2018f - 2018-10-18 00:14:18 -0700
1423 Volgograd moves from +03 to +04 on 2018-10-28.
1424 Fiji ends DST 2019-01-13, not 2019-01-20.
1425 Most of Chile changes DST dates, effective 2019-04-06.
1427 Changes to future timestamps
1429 Volgograd moves from +03 to +04 on 2018-10-28 at 02:00.
1430 (Thanks to Alexander Fetisov and Stepan Golosunov.)
1432 Fiji ends DST 2019-01-13 instead of the 2019-01-20 previously
1433 predicted. (Thanks to Raymond Kumar.) Adjust future predictions
1436 Most of Chile will end DST on the first Saturday in April at 24:00 mainland
1437 time, and resume DST on the first Saturday in September at 24:00 mainland
1438 time. The changes are effective from 2019-04-06, and do not affect the
1439 Magallanes region modeled by America/Punta_Arenas. (Thanks to Juan Correa
1440 and Tim Parenti.) Adjust future predictions accordingly.
1442 Changes to past timestamps
1444 The 2018-05-05 North Korea 30-minute time zone change took place
1445 at 23:30 the previous day, not at 00:00 that day.
1447 China's 1988 spring-forward transition was on April 17, not
1448 April 10. Its DST transitions in 1986/91 were at 02:00, not 00:00.
1451 Fix several issues for Macau before 1992. Macau's pre-1904 LMT
1452 was off by 10 s. Macau switched to +08 in 1904 not 1912, and
1453 temporarily switched to +09/+10 during World War II. Macau
1454 observed DST in 1942/79, not 1961/80, and there were several
1455 errors for transition times and dates. (Thanks to P Chan.)
1457 The 1948-1951 fallback transitions in Japan were at 25:00 on
1458 September's second Saturday, not at 24:00. (Thanks to Phake Nick.)
1459 zic turns this into 01:00 on the day after September's second
1460 Saturday, which is the best that POSIX or C platforms can do.
1462 Incorporate 1940-1949 Asia/Shanghai DST transitions from a 2014
1463 paper by Li Yu, replacing more-questionable data from Shanks.
1465 Changes to time zone abbreviations
1467 Use "PST" and "PDT" for Philippine time. (Thanks to Paul Goyette.)
1471 zic now always generates TZif files where time type 0 is used for
1472 timestamps before the first transition. This simplifies the
1473 reading of TZif files and should not affect behavior of existing
1474 TZif readers because the same set of time types is used; only
1475 their internal indexes may have changed. This affects only the
1476 legacy zones EST5EDT, CST6CDT, MST7MDT, PST8PDT, CET, MET, and
1477 EET, which previously used nonzero types for these timestamps.
1479 Because of the type 0 change, zic no longer outputs a dummy
1480 transition at time -2**59 (before the Big Bang), as clients should
1481 no longer need this to handle historical timestamps correctly.
1482 This reverts a change introduced in 2013d and shrinks most TZif
1483 files by a few bytes.
1485 zic now supports negative time-of-day in Rule and Leap lines, e.g.,
1486 "Rule X min max - Apr lastSun -6:00 1:00 -" means the transition
1487 occurs at 18:00 on the Saturday before the last Sunday in April.
1488 This behavior was documented in 2018a but the code did not
1489 entirely match the documentation.
1491 localtime.c no longer requires at least one time type in TZif
1492 files that lack transitions or have a POSIX-style TZ string. This
1493 future-proofs the code against possible future extensions to the
1494 format that would allow TZif files with POSIX-style TZ strings and
1495 without transitions or time types.
1497 A read-access subscript error in localtime.c has been fixed.
1498 It could occur only in TZif files with timecnt == 0, something that
1499 does not happen in practice now but could happen in future versions.
1501 localtime.c no longer ignores TZif POSIX-style TZ strings that
1502 specify only standard time. Instead, these TZ strings now
1503 override the default time type for timestamps after the last
1504 transition (or for all timestamps if there are no transitions),
1505 just as DST strings specifying DST have always done.
1507 leapseconds.awk now outputs "#updated" and "#expires" comments,
1508 and supports leap seconds at the ends of months other than June
1509 and December. (Inspired by suggestions from Chris Woodbury.)
1511 Changes to documentation
1513 New restrictions: A Rule name must start with a character that
1514 is neither an ASCII digit nor "-" nor "+", and an unquoted name
1515 should not use characters in the set "!$%&'()*,/:;<=>?@[\]^`{|}~".
1516 The latter restriction makes room for future extensions (a
1517 possibility noted by Tom Lane).
1519 tzfile.5 now documents what time types apply before the first and
1520 after the last transition, if any.
1522 Documentation now uses the spelling "timezone" for a TZ setting
1523 that determines timestamp history, and "time zone" for a
1524 geographic region currently sharing the same standard time.
1526 The name "TZif" is now used for the tz binary data format.
1528 tz-link.htm now mentions the A0 TimeZone Migration utilities.
1529 (Thanks to Aldrin Martoq for the link.)
1531 Changes to build procedure
1533 New 'make' target 'rearguard_tarballs' to build the rearguard
1534 tarball only. This is a convenience on platforms that lack lzip
1535 if you want to build the rearguard tarball. (Problem reported by
1538 tzdata.zi is now more stable from release to release. (Problem
1539 noted by Tom Lane.) It is also a bit shorter.
1541 tzdata.zi now can contain comment lines documenting configuration
1542 information, such as which data format was selected, which input
1543 files were used, and how leap seconds are treated. (Problems
1544 noted by Lester Caine and Brian Inglis.) If the Makefile defaults
1545 are used these comment lines are absent, for backward
1546 compatibility. A redistributor intending to alter its copy of the
1547 files should also append "-LABEL" to the 'version' file's first
1548 line, where "LABEL" identifies the redistributor's change.
1551 Release 2018e - 2018-05-01 23:42:51 -0700
1555 North Korea switches back to +09 on 2018-05-05.
1556 The main format uses negative DST again, for Ireland etc.
1557 'make tarballs' now also builds a rearguard tarball.
1558 New 's' and 'd' suffixes in SAVE columns of Rule and Zone lines.
1560 Changes to past and future timestamps
1562 North Korea switches back from +0830 to +09 on 2018-05-05.
1563 (Thanks to Kang Seonghoon, Arthur David Olson, Seo Sanghyeon,
1566 Bring back the negative-DST changes of 2018a, except be more
1567 compatible with data parsers that do not support negative DST.
1568 Also, this now affects historical timestamps in Namibia and the
1569 former Czechoslovakia, not just Ireland. The main format now uses
1570 negative DST to model timestamps in Europe/Dublin (from 1971 on),
1571 Europe/Prague (1946/7), and Africa/Windhoek (1994/2017). This
1572 does not affect UT offsets, only time zone abbreviations and the
1573 tm_isdst flag. Also, this does not affect rearguard or vanguard
1574 formats; effectively the main format now uses vanguard instead of
1575 rearguard format. Data parsers that do not support negative DST
1576 can still use data from the rearguard tarball described below.
1578 Changes to build procedure
1580 The command 'make tarballs' now also builds the tarball
1581 tzdataVERSION-rearguard.tar.gz, which is like tzdataVERSION.tar.gz
1582 except that it uses rearguard format intended for trailing-edge
1585 Changes to data format and to code
1587 The SAVE column of Rule and Zone lines can now have an 's' or 'd'
1588 suffix, which specifies whether the adjusted time is standard time
1589 or daylight saving time. If no suffix is given, daylight saving
1590 time is used if and only if the SAVE column is nonzero; this is
1591 the longstanding behavior. Although this new feature is not used
1592 in tzdata, it could be used to specify the legal time in Namibia
1593 1994-2017, as opposed to the popular time (see below).
1595 Changes to past timestamps
1597 From 1994 through 2017 Namibia observed DST in winter, not summer.
1598 That is, it used negative DST, as Ireland still does. This change
1599 does not affect UTC offsets; it affects only the tm_isdst flag and
1600 the abbreviation used during summer, which is now CAT, not WAST.
1601 Although (as noted by Michael Deckers) summer and winter time were
1602 both simply called "standard time" in Namibian law, in common
1603 practice winter time was considered to be DST (as noted by Stephen
1604 Colebourne). The full effect of this change is only in vanguard
1605 and main format; in rearguard format, the tm_isdst flag is still
1606 zero in winter and nonzero in summer.
1608 In 1946/7 Czechoslovakia also observed negative DST in winter.
1609 The full effect of this change is only in vanguard and main
1610 formats; in rearguard format, it is modeled as plain GMT without
1611 daylight saving. Also, the dates of some 1944/5 DST transitions
1612 in Czechoslovakia have been changed.
1615 Release 2018d - 2018-03-22 07:05:46 -0700
1619 Palestine starts DST a week earlier in 2018.
1620 Add support for vanguard and rearguard data consumers.
1621 Add subsecond precision to source data format, though not to data.
1623 Changes to future timestamps
1625 In 2018, Palestine starts DST on March 24, not March 31.
1626 Adjust future predictions accordingly. (Thanks to Sharef Mustafa.)
1628 Changes to past and future timestamps
1630 Casey Station in Antarctica changed from +11 to +08 on 2018-03-11
1631 at 04:00. (Thanks to Steffen Thorsen.)
1633 Changes to past timestamps
1635 Historical transitions for Uruguay, represented by
1636 America/Montevideo, have been updated per official legal documents,
1637 replacing previous data mainly originating from the inventions of
1638 Shanks & Pottenger. This has resulted in adjustments ranging from
1639 30 to 90 minutes in either direction over at least two dozen
1640 distinct periods ranging from one day to several years in length.
1641 A mere handful of pre-1991 transitions are unaffected; data since
1642 then has come from more reliable contemporaneous reporting. These
1643 changes affect various timestamps in 1920-1923, 1936, 1939,
1644 1942-1943, 1959, 1966-1970, 1972, 1974-1980, and 1988-1990.
1645 Additionally, Uruguay's pre-standard-time UT offset has been
1646 adjusted westward by 7 seconds, from UT-03:44:44 to UT-03:44:51, to
1647 match the location of the Observatory of the National Meteorological
1648 Institute in Montevideo.
1649 (Thanks to Jeremie Bonjour, Tim Parenti, and Michael Deckers.)
1651 East Kiribati skipped New Year's Eve 1994, not New Year's Day 1995.
1652 (Thanks to Kerry Shetline.)
1654 Fix the 1912-01-01 transition for Portugal and its colonies.
1655 This transition was at 00:00 according to the new UT offset, not
1656 according to the old one. Also assume that Cape Verde switched on
1657 the same date as the rest, not in 1907. This affects
1658 Africa/Bissau, Africa/Sao_Tome, Asia/Macau, Atlantic/Azores,
1659 Atlantic/Cape_Verde, Atlantic/Madeira, and Europe/Lisbon.
1660 (Thanks to Michael Deckers.)
1662 Fix an off-by-1 error for pre-1913 timestamps in Jamaica and in
1665 Changes to past time zone abbreviations
1667 MMT took effect in Uruguay from 1908-06-10, not 1898-06-28. There
1668 is no clock change associated with the transition.
1670 Changes to build procedure
1672 The new DATAFORM macro in the Makefile lets the installer choose
1673 among three source data formats. The idea is to lessen downstream
1674 disruption when data formats are improved.
1676 * DATAFORM=vanguard installs from the latest, bleeding-edge
1677 format. DATAFORM=main (the default) installs from the format
1678 used in the 'africa' etc. files. DATAFORM=rearguard installs
1679 from a trailing-edge format. Eventually, elements of today's
1680 vanguard format should move to the main format, and similarly
1681 the main format's features should eventually move to the
1684 * In the current version, the main and rearguard formats are
1685 identical and match that of 2018c, so this change does not
1686 affect default behavior. The vanguard format currently contains
1687 one feature not in the main format: negative SAVE values. This
1688 improves support for Ireland, which uses Irish Standard Time
1689 (IST, UTC+01) in summer and GMT (UTC) in winter. tzcode has
1690 supported negative SAVE values for decades, and this feature
1691 should move to the main format soon. However, it will not move
1692 to the rearguard format for quite some time because some
1693 downstream parsers do not support it.
1695 * The build procedure constructs three files vanguard.zi, main.zi,
1696 and rearguard.zi, one for each format. Although the files
1697 represent essentially the same data, they may have minor
1698 discrepancies that users are not likely to notice. The files
1699 are intended for downstream data consumers and are not
1700 installed. Zoneinfo parsers that do not support negative SAVE values
1701 should start using rearguard.zi, so that they will be unaffected
1702 when the negative-DST feature moves from vanguard to main.
1703 Bleeding-edge Zoneinfo parsers that support the new features
1704 already can use vanguard.zi; in this respect, current tzcode is
1707 The Makefile should now be safe for parallelized builds, and 'make
1708 -j to2050new.tzs' is now much faster on a multiprocessor host
1711 When built with -DSUPPRESS_TZDIR, the tzcode library no longer
1712 prepends TZDIR/ to file names that do not begin with '/'. This is
1713 not recommended for general use, due to its security implications.
1714 (From a suggestion by Manuela Friedrich.)
1718 zic now accepts subsecond precision in expressions like
1719 00:19:32.13, which is approximately the legal time of the
1720 Netherlands from 1835 to 1937. However, because it is
1721 questionable whether the few recorded uses of non-integer offsets
1722 had subsecond precision in practice, there are no plans for tzdata
1723 to use this feature. (Thanks to Steve Allen for pointing out
1724 the limitations of historical data in this area.)
1726 The code is a bit more portable to MS-Windows. Installers can
1727 compile with -DRESERVE_STD_EXT_IDS on MS-Windows platforms that
1728 reserve identifiers like 'localtime'. (Thanks to Manuela
1731 Changes to documentation and commentary
1733 theory.html now outlines tzdb's extensions to POSIX's model for
1734 civil time, and has a section "POSIX features no longer needed"
1735 that lists POSIX API components that are now vestigial.
1736 (From suggestions by Steve Summit.) It also better distinguishes
1737 time zones from tz regions. (From a suggestion by Guy Harris.)
1739 Commentary is now more consistent about using the phrase "daylight
1740 saving time", to match the C name tm_isdst. Daylight saving time
1741 need not occur in summer, and need not have a positive offset from
1744 Commentary about historical transitions in Uruguay has been expanded
1745 with links to many relevant legal documents.
1746 (Thanks to Tim Parenti.)
1748 Commentary now uses some non-ASCII characters with Unicode value
1749 less than U+0100, as they can be useful and should work even with
1750 older editors such as XEmacs.
1753 Release 2018c - 2018-01-22 23:00:44 -0800
1756 Revert Irish changes that relied on negative SAVE values.
1760 Revert the 2018a change to Europe/Dublin. As before, this change
1761 does not affect UT offsets or abbreviations; it affects only
1762 whether timestamps are considered to be standard time or
1763 daylight-saving time, as expressed in the tm_isdst flag of C's
1764 struct tm type. This reversion is intended to be a temporary
1765 workaround for problems discovered with downstream uses of
1766 releases 2018a and 2018b, which implemented Irish time by using
1767 negative SAVE values in the Eire rules of the 'europe' file.
1768 Although negative SAVE values have been part of tzcode for many
1769 years and are supported by many platforms, they were not
1770 documented before 2018a and ICU and OpenJDK do not currently
1771 support them. A mechanism to export data to platforms lacking
1772 support for negative DST is planned to be developed before the
1773 change is reapplied. (Problems reported by Deborah Goldsmith and
1774 Stephen Colebourne.)
1776 Changes to past timestamps
1778 Japanese DST transitions (1948-1951) were Sundays at 00:00, not
1779 Saturdays or Sundays at 02:00. (Thanks to Takayuki Nikai.)
1781 Changes to build procedure
1783 The build procedure now works around mawk 1.3.3's lack of support
1784 for character class expressions. (Problem reported by Ohyama.)
1787 Release 2018b - 2018-01-17 23:24:48 -0800
1790 Fix a packaging problem in tz2018a, which was missing 'pacificnew'.
1792 Changes to build procedure
1794 The distribution now contains the file 'pacificnew' again.
1795 This file was inadvertently omitted in the 2018a distribution.
1796 (Problem reported by Matias Fonzo.)
1799 Release 2018a - 2018-01-12 22:29:21 -0800
1802 São Tomé and Príncipe switched from +00 to +01.
1803 Brazil's DST will now start on November's first Sunday.
1804 Ireland's standard time is now in the summer, not the winter.
1805 Use Debian-style installation locations, instead of 4.3BSD-style.
1808 Changes to past and future timestamps
1810 São Tomé and Príncipe switched from +00 to +01 on 2018-01-01 at
1811 01:00. (Thanks to Steffen Thorsen and Michael Deckers.)
1813 Changes to future timestamps
1815 Starting in 2018 southern Brazil will begin DST on November's
1816 first Sunday instead of October's third Sunday. (Thanks to
1819 Changes to past timestamps
1821 A discrepancy of 4 s in timestamps before 1931 in South Sudan has
1822 been corrected. The 'backzone' and 'zone.tab' files did not agree
1823 with the 'africa' and 'zone1970.tab' files. (Problem reported by
1826 The abbreviation invented for Bolivia Summer Time (1931-2) is now
1827 BST instead of BOST, to be more consistent with the convention
1828 used for Latvian Summer Time (1918-9) and for British Summer Time.
1832 Change Europe/Dublin so that it observes Irish Standard Time (UT
1833 +01) in summer and GMT (as negative daylight-saving) in winter,
1834 instead of observing standard time (GMT) in winter and Irish
1835 Summer Time (UT +01) in summer. This change does not affect UT
1836 offsets or abbreviations; it affects only whether timestamps are
1837 considered to be standard time or daylight-saving time, as
1838 expressed in the tm_isdst flag of C's struct tm type.
1839 (Discrepancy noted by Derick Rethans.)
1841 Changes to build procedure
1843 The default installation locations have been changed to mostly
1844 match Debian circa 2017, instead of being designed as an add-on to
1845 4.3BSD circa 1986. This affects the Makefile macros TOPDIR,
1846 TZDIR, MANDIR, and LIBDIR. New Makefile macros TZDEFAULT, USRDIR,
1847 USRSHAREDIR, BINDIR, ZDUMPDIR, and ZICDIR let installers tailor
1848 locations more precisely. (This responds to suggestions from
1849 Brian Inglis and from Steve Summit.)
1851 The default installation procedure no longer creates the
1852 backward-compatibility link US/Pacific-New, which causes
1853 confusion during user setup (e.g., see Debian bug 815200).
1854 Use 'make BACKWARD="backward pacificnew"' to create the link
1855 anyway, for now. Eventually we plan to remove the link entirely.
1857 tzdata.zi now contains a version-number comment.
1858 (Suggested by Tom Lane.)
1860 The Makefile now quotes values like BACKWARD more carefully when
1861 passing them to the shell. (Problem reported by Zefram.)
1863 Builders no longer need to specify -DHAVE_SNPRINTF on platforms
1864 that have snprintf and use pre-C99 compilers. (Problem reported
1869 zic has a new option -t FILE that specifies the location of the
1870 file that determines local time when TZ is unset. The default for
1871 this location can be configured via the new TZDEFAULT makefile
1872 macro, which defaults to /etc/localtime.
1874 Diagnostics and commentary now distinguish UT from UTC more
1875 carefully; see theory.html for more information about UT vs UTC.
1877 zic has been ported to GCC 8's -Wstringop-truncation option.
1878 (Problem reported by Martin Sebor.)
1880 Changes to documentation and commentary
1882 The zic man page now documents the longstanding behavior that
1883 times and years can be out of the usual range, with negative times
1884 counting backwards from midnight and with year 0 preceding year 1.
1885 (Problem reported by Michael Deckers.)
1887 The theory.html file now mentions the POSIX limit of six chars
1888 per abbreviation, and lists alphabetic abbreviations used.
1890 The files tz-art.htm and tz-link.htm have been renamed to
1891 tz-art.html and tz-link.html, respectively, for consistency with
1892 other file names and to simplify web server configuration.
1895 Release 2017c - 2017-10-20 14:49:34 -0700
1898 Northern Cyprus switches from +03 to +02/+03 on 2017-10-29.
1899 Fiji ends DST 2018-01-14, not 2018-01-21.
1900 Namibia switches from +01/+02 to +02 on 2018-04-01.
1901 Sudan switches from +03 to +02 on 2017-11-01.
1902 Tonga likely switches from +13/+14 to +13 on 2017-11-05.
1903 Turks & Caicos switches from -04 to -05/-04 on 2018-11-04.
1904 A new file tzdata.zi now holds a small text copy of all data.
1905 The zic input format has been regularized slightly.
1907 Changes to future timestamps
1909 Northern Cyprus has decided to resume EU rules starting
1910 2017-10-29, thus reinstituting winter time.
1912 Fiji ends DST 2018-01-14 instead of the 2018-01-21 previously
1913 predicted. (Thanks to Dominic Fok.) Adjust future predictions
1916 Namibia will switch from +01 with DST to +02 all year on
1917 2017-09-03 at 02:00. This affects UT offsets starting 2018-04-01
1918 at 02:00. (Thanks to Steffen Thorsen.)
1920 Sudan will switch from +03 to +02 on 2017-11-01. (Thanks to Ahmed
1921 Atyya and Yahia Abdalla.) South Sudan is not switching, so
1922 Africa/Juba is no longer a link to Africa/Khartoum.
1924 Tonga has likely ended its experiment with DST, and will not
1925 adjust its clocks on 2017-11-05. Although Tonga has not announced
1926 whether it will continue to observe DST, the IATA is assuming that
1927 it will not. (Thanks to David Wade.)
1929 Turks & Caicos will switch from -04 all year to -05 with US DST on
1930 2018-03-11 at 03:00. This affects UT offsets starting 2018-11-04
1931 at 02:00. (Thanks to Steffen Thorsen.)
1933 Changes to past timestamps
1935 Namibia switched from +02 to +01 on 1994-03-21, not 1994-04-03.
1936 (Thanks to Arthur David Olson.)
1938 Detroit did not observe DST in 1967.
1940 Use railway time for Asia/Kolkata before 1941, by switching to
1941 Madras local time (UT +052110) in 1870, then to IST (UT +0530) in
1942 1906. Also, treat 1941-2's +0630 as DST, like 1942-5.
1944 Europe/Dublin's 1946 and 1947 fallback transitions occurred at
1945 02:00 standard time, not 02:00 DST. (Thanks to Michael Deckers.)
1947 Pacific/Apia and Pacific/Pago_Pago switched from Antipodean to
1948 American time in 1892, not 1879. (Thanks to Michael Deckers.)
1950 Adjust the 1867 transition in Alaska to better reflect the
1951 historical record, by changing it to occur on 1867-10-18 at 15:30
1952 Sitka time rather than at the start of 1867-10-17 local time.
1953 Although strictly speaking this is accurate only for Sitka,
1954 the rest of Alaska's blanks need to be filled in somehow.
1956 Fix off-by-one errors in UT offsets for Adak and Nome before 1867.
1957 (Thanks to Michael Deckers.)
1959 Add 7 s to the UT offset in Asia/Yangon before 1920.
1961 Changes to zone names
1963 Remove Canada/East-Saskatchewan from the 'backward' file, as it
1964 exceeded the 14-character limit and was an unused misnomer anyway.
1966 Changes to build procedure
1968 To support applications that prefer to read time zone data in text
1969 form, two zic input files tzdata.zi and leapseconds are now
1970 installed by default. The commands 'zic tzdata.zi' and 'zic -L
1971 leapseconds tzdata.zi' can reproduce the tzdata binary files
1972 without and with leap seconds, respectively. To prevent these two
1973 new files from being installed, use 'make TZDATA_TEXT=', and to
1974 suppress leap seconds from the tzdata text installation, use 'make
1975 TZDATA_TEXT=tzdata.zi'.
1977 'make BACKWARD=' now suppresses backward-compatibility names
1978 like 'US/Pacific' that are defined in the 'backward' and
1981 'make check' now works on systems that lack a UTF-8 locale,
1982 or that lack the nsgmls program. Set UTF8_LOCALE to configure
1983 the name of a UTF-8 locale, if you have one.
1985 Y2K runtime checks are no longer enabled by default. Add
1986 -DDEPRECATE_TWO_DIGIT_YEARS to CFLAGS to enable them, instead of
1987 adding -DNO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
1988 to disable them. (New name suggested by Brian Inglis.)
1990 The build procedure for zdump now works on AIX 7.1.
1991 (Problem reported by Kees Dekker.)
1995 zic and the reference runtime now reject multiple leap seconds
1996 within 28 days of each other, or leap seconds before the Epoch.
1997 As a result, support for double leap seconds, which was
1998 obsolescent and undocumented, has been removed. Double leap
1999 seconds were an error in the C89 standard; they have never existed
2000 in civil timekeeping. (Thanks to Robert Elz and Bradley White for
2001 noticing glitches in the code that uncovered this problem.)
2003 zic now warns about use of the obsolescent and undocumented -y
2004 option, and about use of the obsolescent TYPE field of Rule lines.
2006 zic now allows unambiguous abbreviations like "Sa" and "Su" for
2007 weekdays; formerly it rejected them due to a bug. Conversely, zic
2008 no longer considers non-prefixes to be abbreviations; for example,
2009 it no longer accepts "lF" as an abbreviation for "lastFriday".
2010 Also, zic warns about the undocumented usage with a "last-"
2011 prefix, e.g., "last-Fri".
2013 Similarly, zic now accepts the unambiguous abbreviation "L" for
2014 "Link" in ordinary context and for "Leap" in leap-second context.
2015 Conversely, zic no longer accepts non-prefixes such as "La" as
2016 abbreviations for words like "Leap".
2018 zic no longer accepts leap second lines in ordinary input, or
2019 ordinary lines in leap second input. Formerly, zic sometimes
2020 warned about this undocumented usage and handled it incorrectly.
2022 The new macro HAVE_TZNAME governs whether the tzname external
2023 variable is exported, instead of USG_COMPAT. USG_COMPAT now
2024 governs only the external variables "timezone" and "daylight".
2025 This change is needed because the three variables are not in the
2026 same category: although POSIX requires tzname, it specifies the
2027 other two variables as optional. Also, USG_COMPAT is now 1 or 0:
2028 if not defined, the code attempts to guess it from other macros.
2030 localtime.c and difftime.c no longer require stdio.h, and .c files
2031 other than zic.c no longer require sys/wait.h.
2033 zdump.c no longer assumes snprintf. (Reported by Jonathan Leffler.)
2035 Calculation of time_t extrema works around a bug in GCC 4.8.4
2036 (Reported by Stan Shebs and Joseph Myers.)
2038 zic.c no longer mistranslates formats of line numbers in non-English
2039 locales. (Problem reported by Benno Schulenberg.)
2041 Several minor changes have been made to the code to make it a
2042 bit easier to port to MS-Windows and Solaris. (Thanks to Kees
2043 Dekker for reporting the problems.)
2045 Changes to documentation and commentary
2047 The two new files 'theory.html' and 'calendars' contain the
2048 contents of the removed file 'Theory'. The goal is to document
2049 tzdb theory more accessibly.
2051 The zic man page now documents abbreviation rules.
2053 tz-link.htm now covers how to apply tzdata changes to clients.
2054 (Thanks to Jorge Fábregas for the AIX link.) It also mentions MySQL.
2056 The leap-seconds.list URL has been updated to something that is
2057 more reliable for tzdb. (Thanks to Tim Parenti and Brian Inglis.)
2059 Release 2017b - 2017-03-17 07:30:38 -0700
2061 Briefly: Haiti has resumed DST.
2063 Changes to past and future timestamps
2065 Haiti resumed observance of DST in 2017. (Thanks to Steffen Thorsen.)
2067 Changes to past timestamps
2069 Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
2071 Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
2072 is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
2076 The reference localtime implementation now falls back on the
2077 current US daylight-saving transition rules rather than the
2078 1987-2006 rules. This fallback occurs only when (1) the TZ
2079 environment variable has a value like "AST4ADT" that asks
2080 for daylight saving time but does not specify the rules, (2) there
2081 is no file by that name, and (3) the TZDEFRULES file cannot be
2082 loaded. (Thanks to Tom Lane.)
2085 Release 2017a - 2017-02-28 00:05:36 -0800
2087 Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
2090 Changes to future timestamps
2092 Mongolia no longer observes DST. (Thanks to Ganbold Tsagaankhuu.)
2094 Chile's Region of Magallanes moves from -04/-03 to -03 year-round.
2095 Its clocks diverge from America/Santiago starting 2017-05-13 at
2096 23:00, hiving off a new zone America/Punta_Arenas. Although the
2097 Chilean government says this change expires in May 2019, for now
2098 assume it's permanent. (Thanks to Juan Correa and Deborah
2099 Goldsmith.) This also affects Antarctica/Palmer.
2101 Changes to past timestamps
2103 Fix many entries for historical timestamps for Europe/Madrid
2104 before 1979, to agree with tables compiled by Pere Planesas of the
2105 National Astronomical Observatory of Spain. As a side effect,
2106 this changes some timestamps for Africa/Ceuta before 1929, which
2107 are probably guesswork anyway. (Thanks to Steve Allen and
2108 Pierpaolo Bernardi for the heads-ups, and to Michael Deckers for
2109 correcting the 1901 transition.)
2111 Ecuador observed DST from 1992-11-28 to 1993-02-05.
2112 (Thanks to Alois Treindl.)
2114 Asia/Atyrau and Asia/Oral were at +03 (not +04) before 1930-06-21.
2115 (Thanks to Stepan Golosunov.)
2117 Changes to past and future time zone abbreviations
2119 Switch to numeric time zone abbreviations for South America, as
2120 part of the ongoing project of removing invented abbreviations.
2121 This avoids the need to invent an abbreviation for the new Chilean
2122 new zone. Similarly, switch from invented to numeric time zone
2123 abbreviations for Afghanistan, American Samoa, the Azores,
2124 Bangladesh, Bhutan, the British Indian Ocean Territory, Brunei,
2125 Cape Verde, Chatham Is, Christmas I, Cocos (Keeling) Is, Cook Is,
2126 Dubai, East Timor, Eucla, Fiji, French Polynesia, Greenland,
2127 Indochina, Iran, Iraq, Kiribati, Lord Howe, Macquarie, Malaysia,
2128 the Maldives, Marshall Is, Mauritius, Micronesia, Mongolia,
2129 Myanmar, Nauru, Nepal, New Caledonia, Niue, Norfolk I, Palau,
2130 Papua New Guinea, the Philippines, Pitcairn, Qatar, Réunion, St
2131 Pierre & Miquelon, Samoa, Saudi Arabia, Seychelles, Singapore,
2132 Solomon Is, Tokelau, Tuvalu, Wake, Vanuatu, Wallis & Futuna, and
2133 Xinjiang; for 20-minute daylight saving time in Ghana before 1943;
2134 for half-hour daylight saving time in Belize before 1944 and in
2135 the Dominican Republic before 1975; and for Canary Islands before
2136 1946, for Guinea-Bissau before 1975, for Iceland before 1969, for
2137 Indian Summer Time before 1942, for Indonesia before around 1964,
2138 for Kenya before 1960, for Liberia before 1973, for Madeira before
2139 1967, for Namibia before 1943, for the Netherlands in 1937-9, for
2140 Pakistan before 1971, for Western Sahara before 1977, and for
2141 Zaporozhye in 1880-1924.
2143 For Alaska time from 1900 through 1967, instead of "CAT" use the
2144 abbreviation "AST", the abbreviation commonly used at the time
2145 (Atlantic Standard Time had not been standardized yet). Use "AWT"
2146 and "APT" instead of the invented abbreviations "CAWT" and "CAPT".
2148 Use "CST" and "CDT" instead of invented abbreviations for Macau
2149 before 1999 and Taiwan before 1938, and use "JST" instead of the
2150 invented abbreviation "JCST" for Japan and Korea before 1938.
2152 Change to database entry category
2154 Move the Pacific/Johnston link from 'australasia' to 'backward',
2155 since Johnston is now uninhabited.
2159 zic no longer mishandles some transitions in January 2038 when it
2160 attempts to work around Qt bug 53071. This fixes a bug affecting
2161 Pacific/Tongatapu that was introduced in zic 2016e. localtime.c
2162 now contains a workaround, useful when loading a file generated by
2163 a buggy zic. (Problem and localtime.c fix reported by Bradley
2166 zdump -i now outputs non-hour numeric time zone abbreviations
2167 without a colon, e.g., "+0530" rather than "+05:30". This agrees
2168 with zic %z and with common practice, and simplifies auditing of
2171 zdump is now buildable again with -DUSE_LTZ=0.
2172 (Problem reported by Joseph Myers.)
2174 zdump.c now always includes private.h, to avoid code duplication
2175 with private.h. (Problem reported by Kees Dekker.)
2177 localtime.c no longer mishandles early or late timestamps
2178 when TZ is set to a POSIX-style string that specifies DST.
2179 (Problem reported by Kees Dekker.)
2181 date and strftime now cause %z to generate "-0000" instead of
2182 "+0000" when the UT offset is zero and the time zone abbreviation
2185 Changes to documentation and commentary
2187 The 'Theory' file now better documents choice of historical time
2188 zone abbreviations. (Problems reported by Michael Deckers.)
2190 tz-link.htm now covers leap smearing, which is popular in clouds.
2193 Release 2016j - 2016-11-22 23:17:13 -0800
2195 Briefly: Saratov, Russia moves from +03 to +04 on 2016-12-04.
2197 Changes to future timestamps
2199 Saratov, Russia switches from +03 to +04 on 2016-12-04 at 02:00.
2200 This hives off a new zone Europe/Saratov from Europe/Volgograd.
2201 (Thanks to Yuri Konotopov and Stepan Golosunov.)
2203 Changes to past timestamps
2205 The new zone Asia/Atyrau for Atyraū Region, Kazakhstan, is like
2206 Asia/Aqtau except it switched from +05/+06 to +04/+05 in spring
2207 1999, not fall 1994. (Thanks to Stepan Golosunov.)
2209 Changes to past time zone abbreviations
2211 Asia/Gaza and Asia/Hebron now use "EEST", not "EET", to denote
2212 summer time before 1948. The old use of "EET" was a typo.
2216 zic no longer mishandles file systems that lack hard links, fixing
2217 bugs introduced in 2016g. (Problems reported by Tom Lane.)
2218 Also, when the destination already contains symbolic links, zic
2219 should now work better on systems where the 'link' system call
2220 does not follow symbolic links.
2222 Changes to documentation and commentary
2224 tz-link.htm now documents the relationship between release version
2225 numbers and development-repository commit tags. (Suggested by
2228 The 'Theory' file now documents UT.
2230 iso3166.tab now accents "Curaçao", and commentary now mentions
2231 the names "Cabo Verde" and "Czechia". (Thanks to Jiří Boháč.)
2234 Release 2016i - 2016-11-01 23:19:52 -0700
2236 Briefly: Cyprus split into two time zones on 2016-10-30, and Tonga
2237 reintroduces DST on 2016-11-06.
2239 Changes to future timestamps
2241 Pacific/Tongatapu begins DST on 2016-11-06 at 02:00, ending on
2242 2017-01-15 at 03:00. Assume future observances in Tonga will be
2243 from the first Sunday in November through the third Sunday in
2244 January, like Fiji. (Thanks to Pulu ʻAnau.) Switch to numeric
2245 time zone abbreviations for this zone.
2247 Changes to past and future timestamps
2249 Northern Cyprus is now +03 year round, causing a split in Cyprus
2250 time zones starting 2016-10-30 at 04:00. This creates a zone
2251 Asia/Famagusta. (Thanks to Even Scharning and Matt Johnson.)
2253 Antarctica/Casey switched from +08 to +11 on 2016-10-22.
2254 (Thanks to Steffen Thorsen.)
2256 Changes to past timestamps
2258 Several corrections were made for pre-1975 timestamps in Italy.
2259 These affect Europe/Malta, Europe/Rome, Europe/San_Marino, and
2262 First, the 1893-11-01 00:00 transition in Italy used the new UT
2263 offset (+01), not the old (+00:49:56). (Thanks to Michael
2266 Second, rules for daylight saving in Italy were changed to agree
2267 with Italy's National Institute of Metrological Research (INRiM)
2268 except for 1944, as follows (thanks to Pierpaolo Bernardi, Brian
2269 Inglis, and Michael Deckers):
2271 The 1916-06-03 transition was at 24:00, not 00:00.
2273 The 1916-10-01, 1919-10-05, and 1920-09-19 transitions were at
2276 The 1917-09-30 and 1918-10-06 transitions were at 24:00, not
2279 The 1944-09-17 transition was at 03:00, not 01:00. This
2280 particular change is taken from Italian law as INRiM's table,
2281 (which says 02:00) appears to have a typo here. Also, keep the
2282 1944-04-03 transition for Europe/Rome, as Rome was controlled by
2285 The 1967-1970 and 1972-1974 fallback transitions were at 01:00,
2290 The code should now be buildable on AmigaOS merely by setting the
2291 appropriate Makefile variables. (From a patch by Carsten Larsen.)
2294 Release 2016h - 2016-10-19 23:17:57 -0700
2296 Changes to future timestamps
2298 Asia/Gaza and Asia/Hebron end DST on 2016-10-29 at 01:00, not
2299 2016-10-21 at 00:00. (Thanks to Sharef Mustafa.) Predict that
2300 future fall transitions will be on the last Saturday of October
2301 at 01:00, which is consistent with predicted spring transitions
2302 on the last Saturday of March. (Thanks to Tim Parenti.)
2304 Changes to past timestamps
2306 In Turkey, transitions in 1986-1990 were at 01:00 standard time
2307 not at 02:00, and the spring 1994 transition was on March 20, not
2308 March 27. (Thanks to Kıvanç Yazan.)
2310 Changes to past and future time zone abbreviations
2312 Asia/Colombo now uses numeric time zone abbreviations like "+0530"
2313 instead of alphabetic ones like "IST" and "LKT". Various
2314 English-language sources use "IST", "LKT" and "SLST", with no
2315 working consensus. (Usage of "SLST" mentioned by Sadika
2320 zic no longer mishandles relativizing file names when creating
2321 symbolic links like /etc/localtime, when these symbolic links
2322 are outside the usual directory hierarchy. This fixes a bug
2323 introduced in 2016g. (Problem reported by Andreas Stieger.)
2325 Changes to build procedure
2327 New rules 'traditional_tarballs' and 'traditional_signatures' for
2328 building just the traditional-format distribution. (Requested by
2331 The file 'version' is now put into the tzdata tarball too.
2332 (Requested by Howard Hinnant.)
2334 Changes to documentation and commentary
2336 The 'Theory' file now has a section on interface stability.
2337 (Requested by Paul Koning.) It also mentions features like
2338 tm_zone and localtime_rz that have long been supported by the
2341 tz-link.htm has improved coverage of time zone boundaries suitable
2342 for geolocation. (Thanks to heads-ups from Evan Siroky and Matt
2345 The US commentary now mentions Allen and the "day of two noons".
2347 The Fiji commentary mentions the government's 2016-10-03 press
2348 release. (Thanks to Raymond Kumar.)
2351 Release 2016g - 2016-09-13 08:56:38 -0700
2353 Changes to future timestamps
2355 Turkey switched from EET/EEST (+02/+03) to permanent +03,
2356 effective 2016-09-07. (Thanks to Burak AYDIN.) Use "+03" rather
2357 than an invented abbreviation for the new time.
2359 New leap second 2016-12-31 23:59:60 UTC as per IERS Bulletin C 52.
2360 (Thanks to Tim Parenti.)
2362 Changes to past timestamps
2364 For America/Los_Angeles, spring-forward transition times have been
2365 corrected from 02:00 to 02:01 in 1948, and from 02:00 to 01:00 in
2368 For zones using Soviet time on 1919-07-01, transitions to UT-based
2369 time were at 00:00 UT, not at 02:00 local time. The affected
2370 zones are Europe/Kirov, Europe/Moscow, Europe/Samara, and
2371 Europe/Ulyanovsk. (Thanks to Alexander Belopolsky.)
2373 Changes to past and future time zone abbreviations
2375 The Factory zone now uses the time zone abbreviation -00 instead
2376 of a long English-language string, as -00 is now the normal way to
2377 represent an undefined time zone.
2379 Several zones in Antarctica and the former Soviet Union, along
2380 with zones intended for ships at sea that cannot use POSIX TZ
2381 strings, now use numeric time zone abbreviations instead of
2382 invented or obsolete alphanumeric abbreviations. The affected
2383 zones are Antarctica/Casey, Antarctica/Davis,
2384 Antarctica/DumontDUrville, Antarctica/Mawson, Antarctica/Rothera,
2385 Antarctica/Syowa, Antarctica/Troll, Antarctica/Vostok,
2386 Asia/Anadyr, Asia/Ashgabat, Asia/Baku, Asia/Bishkek, Asia/Chita,
2387 Asia/Dushanbe, Asia/Irkutsk, Asia/Kamchatka, Asia/Khandyga,
2388 Asia/Krasnoyarsk, Asia/Magadan, Asia/Omsk, Asia/Sakhalin,
2389 Asia/Samarkand, Asia/Srednekolymsk, Asia/Tashkent, Asia/Tbilisi,
2390 Asia/Ust-Nera, Asia/Vladivostok, Asia/Yakutsk, Asia/Yekaterinburg,
2391 Asia/Yerevan, Etc/GMT-14, Etc/GMT-13, Etc/GMT-12, Etc/GMT-11,
2392 Etc/GMT-10, Etc/GMT-9, Etc/GMT-8, Etc/GMT-7, Etc/GMT-6, Etc/GMT-5,
2393 Etc/GMT-4, Etc/GMT-3, Etc/GMT-2, Etc/GMT-1, Etc/GMT+1, Etc/GMT+2,
2394 Etc/GMT+3, Etc/GMT+4, Etc/GMT+5, Etc/GMT+6, Etc/GMT+7, Etc/GMT+8,
2395 Etc/GMT+9, Etc/GMT+10, Etc/GMT+11, Etc/GMT+12, Europe/Kaliningrad,
2396 Europe/Minsk, Europe/Samara, Europe/Volgograd, and
2397 Indian/Kerguelen. For Europe/Moscow the invented abbreviation MSM
2398 was replaced by +05, whereas MSK and MSD were kept as they are not
2399 our invention and are widely used.
2401 Changes to zone names
2403 Rename Asia/Rangoon to Asia/Yangon, with a backward compatibility link.
2404 (Thanks to David Massoud.)
2408 zic no longer generates binary files containing POSIX TZ-like
2409 strings that disagree with the local time type after the last
2410 explicit transition in the data. This fixes a bug with
2411 Africa/Casablanca and Africa/El_Aaiun in some year-2037 timestamps
2412 on the reference platform. (Thanks to Alexander Belopolsky for
2413 reporting the bug and suggesting a way forward.)
2415 If the installed localtime and/or posixrules files are symbolic
2416 links, zic now keeps them symbolic links when updating them, for
2417 compatibility with platforms like OpenSUSE where other programs
2418 configure these files as symlinks.
2420 zic now avoids hard linking to symbolic links, avoids some
2421 unnecessary mkdir and stat system calls, and uses shorter file
2424 zdump has a new -i option to generate transitions in a
2425 smaller but still human-readable format. This option is
2426 experimental, and the output format may change in future versions.
2427 (Thanks to Jon Skeet for suggesting that an option was needed,
2428 and thanks to Tim Parenti and Chris Rovick for further comments.)
2430 Changes to build procedure
2432 An experimental distribution format is available, in addition
2433 to the traditional format which will continue to be distributed.
2434 The new format is a tarball tzdb-VERSION.tar.lz with signature
2435 file tzdb-VERSION.tar.lz.asc. It unpacks to a top-level directory
2436 tzdb-VERSION containing the code and data of the traditional
2437 two-tarball format, along with extra data that may be useful.
2438 (Thanks to Antonio Diaz Diaz, Oscar van Vlijmen, and many others
2439 for comments about the experimental format.)
2441 The release version number is now more accurate in the usual case
2442 where releases are built from a Git repository. For example, if
2443 23 commits and some working-file changes have been made since
2444 release 2016g, the version number is now something like
2445 '2016g-23-g50556e3-dirty' instead of the misleading '2016g'.
2446 Tagged releases use the same version number format as before,
2447 e.g., '2016g'. To support the more accurate version number, its
2448 specification has moved from a line in the Makefile to a new
2449 source file 'version'.
2451 The experimental distribution contains a file to2050.tzs that
2452 contains what should be the output of 'zdump -i -c 2050' on
2453 primary zones. If this file is available, 'make check' now checks
2454 that zdump generates this output.
2456 'make check_web' now works on Fedora-like distributions.
2458 Changes to documentation and commentary
2460 tzfile.5 now documents the new restriction on POSIX TZ-like
2461 strings that is now implemented by zic.
2463 Comments now cite URLs for some 1917-1921 Russian DST decrees.
2464 (Thanks to Alexander Belopolsky.)
2466 tz-link.htm mentions JuliaTime (thanks to Curtis Vogt) and Time4J
2467 (thanks to Meno Hochschild) and ThreeTen-Extra, and its
2468 description of Java 8 has been brought up to date (thanks to
2469 Stephen Colebourne). Its description of local time on Mars has
2470 been updated to match current practice, and URLs have been updated
2471 and some obsolete ones removed.
2474 Release 2016f - 2016-07-05 16:26:51 +0200
2476 Changes affecting future timestamps
2478 The Egyptian government changed its mind on short notice, and
2479 Africa/Cairo will not introduce DST starting 2016-07-07 after all.
2480 (Thanks to Mina Samuel.)
2482 Asia/Novosibirsk switches from +06 to +07 on 2016-07-24 at 02:00.
2483 (Thanks to Stepan Golosunov.)
2485 Changes to past and future timestamps
2487 Asia/Novokuznetsk and Asia/Novosibirsk now use numeric time zone
2488 abbreviations instead of invented ones.
2490 Changes affecting past timestamps
2492 Europe/Minsk's 1992-03-29 spring-forward transition was at 02:00 not 00:00.
2493 (Thanks to Stepan Golosunov.)
2496 Release 2016e - 2016-06-14 08:46:16 -0700
2498 Changes affecting future timestamps
2500 Africa/Cairo observes DST in 2016 from July 7 to the end of October.
2501 Guess October 27 and 24:00 transitions. (Thanks to Steffen Thorsen.)
2502 For future years, guess April's last Thursday to October's last
2503 Thursday except for Ramadan.
2505 Changes affecting past timestamps
2507 Locations while uninhabited now use '-00', not 'zzz', as a
2508 placeholder time zone abbreviation. This is inspired by Internet
2509 RFC 3339 and is more consistent with numeric time zone
2510 abbreviations already used elsewhere. The change affects several
2511 arctic and antarctic locations, e.g., America/Cambridge_Bay before
2512 1920 and Antarctica/Troll before 2005.
2514 Asia/Baku's 1992-09-27 transition from +04 (DST) to +04 (non-DST) was
2515 at 03:00, not 23:00 the previous day. (Thanks to Michael Deckers.)
2519 zic now outputs a dummy transition at time 2**31 - 1 in zones
2520 whose POSIX-style TZ strings contain a '<'. This mostly works
2521 around Qt bug 53071 <https://bugreports.qt.io/browse/QTBUG-53071>.
2522 (Thanks to Zhanibek Adilbekov for reporting the Qt bug.)
2524 Changes affecting documentation and commentary
2526 tz-link.htm says why governments should give plenty of notice for
2527 time zone or DST changes, and refers to Matt Johnson's blog post.
2529 tz-link.htm mentions Tzdata for Elixir. (Thanks to Matt Johnson.)
2532 Release 2016d - 2016-04-17 22:50:29 -0700
2534 Changes affecting future timestamps
2536 America/Caracas switches from -0430 to -04 on 2016-05-01 at 02:30.
2537 (Thanks to Alexander Krivenyshev for the heads-up.)
2539 Asia/Magadan switches from +10 to +11 on 2016-04-24 at 02:00.
2540 (Thanks to Alexander Krivenyshev and Matt Johnson.)
2542 New zone Asia/Tomsk, split off from Asia/Novosibirsk. It covers
2543 Tomsk Oblast, Russia, which switches from +06 to +07 on 2016-05-29
2544 at 02:00. (Thanks to Stepan Golosunov.)
2546 Changes affecting past timestamps
2548 New zone Europe/Kirov, split off from Europe/Volgograd. It covers
2549 Kirov Oblast, Russia, which switched from +04/+05 to +03/+04 on
2550 1989-03-26 at 02:00, roughly a year after Europe/Volgograd made
2551 the same change. (Thanks to Stepan Golosunov.)
2553 Russia and nearby locations had daylight-saving transitions on
2554 1992-03-29 at 02:00 and 1992-09-27 at 03:00, instead of on
2555 1992-03-28 at 23:00 and 1992-09-26 at 23:00. (Thanks to Stepan
2558 Many corrections to historical time in Kazakhstan from 1991
2559 through 2005. (Thanks to Stepan Golosunov.) Replace Kazakhstan's
2560 invented time zone abbreviations with numeric abbreviations.
2562 Changes to commentary
2564 Mention Internet RFCs 7808 (TZDIST) and 7809 (CalDAV time zone references).
2567 Release 2016c - 2016-03-23 00:51:27 -0700
2569 Changes affecting future timestamps
2571 Azerbaijan no longer observes DST. (Thanks to Steffen Thorsen.)
2573 Chile reverts from permanent to seasonal DST. (Thanks to Juan
2574 Correa for the heads-up, and to Tim Parenti for corrections.)
2575 Guess that future transitions are August's and May's second
2576 Saturdays at 24:00 mainland time. Also, call the period from
2577 2014-09-07 through 2016-05-14 daylight saving time instead of
2578 standard time, as that seems more appropriate now.
2580 Changes affecting past timestamps
2582 Europe/Kaliningrad and Europe/Vilnius changed from +03/+04 to
2583 +02/+03 on 1989-03-26, not 1991-03-31. Europe/Volgograd changed
2584 from +04/+05 to +03/+04 on 1988-03-27, not 1989-03-26.
2585 (Thanks to Stepan Golosunov.)
2587 Changes to commentary
2589 Several updates and URLs for historical and proposed Russian changes.
2590 (Thanks to Stepan Golosunov, Matt Johnson, and Alexander Krivenyshev.)
2593 Release 2016b - 2016-03-12 17:30:14 -0800
2597 Starting with release 2016b, some data entries cause zic implementations
2598 derived from tz releases 2005j through 2015e to issue warnings like
2599 "time zone abbreviation differs from POSIX standard (+03)".
2600 These warnings should not otherwise affect zic's output and can safely be
2601 ignored on today's platforms, as the warnings refer to a restriction in
2602 POSIX.1-1988 that was removed in POSIX.1-2001. One way to suppress the
2603 warnings is to upgrade to zic derived from tz releases 2015f and later.
2605 Changes affecting future timestamps
2607 New zones Europe/Astrakhan and Europe/Ulyanovsk for Astrakhan and
2608 Ulyanovsk Oblasts, Russia, both of which will switch from +03 to +04 on
2609 2016-03-27 at 02:00 local time. They need distinct zones since their
2610 post-1970 histories disagree. New zone Asia/Barnaul for Altai Krai and
2611 Altai Republic, Russia, which will switch from +06 to +07 on the same date
2612 and local time. The Astrakhan change is already official; the others have
2613 passed the first reading in the State Duma and are extremely likely.
2614 Also, Asia/Sakhalin moves from +10 to +11 on 2016-03-27 at 02:00.
2615 (Thanks to Alexander Krivenyshev for the heads-up, and to Matt Johnson
2616 and Stepan Golosunov for followup.)
2618 As a trial of a new system that needs less information to be made up,
2619 the new zones use numeric time zone abbreviations like "+04"
2620 instead of invented abbreviations like "ASTT".
2622 Haiti will not observe DST in 2016. (Thanks to Jean Antoine via
2625 Palestine's spring-forward transition on 2016-03-26 is at 01:00, not 00:00.
2626 (Thanks to Hannah Kreitem.) Guess future transitions will be March's last
2627 Saturday at 01:00, not March's last Friday at 24:00.
2629 Changes affecting past timestamps
2631 Europe/Chisinau observed DST during 1990, and switched from +04 to
2632 +03 at 1990-05-06 02:00, instead of switching from +03 to +02.
2633 (Thanks to Stepan Golosunov.)
2635 1991 abbreviations in Europe/Samara should be SAMT/SAMST, not
2636 KUYT/KUYST. (Thanks to Stepan Golosunov.)
2640 tzselect's diagnostics and checking, and checktab.awk's checking,
2641 have been improved. (Thanks to J William Piggott.)
2643 tzcode now builds under MinGW. (Thanks to Ian Abbott and Esben Haabendal.)
2645 tzselect now tests Julian-date TZ settings more accurately.
2646 (Thanks to J William Piggott.)
2648 Changes to commentary
2650 Comments in zone tables have been improved. (Thanks to J William Piggott.)
2652 tzselect again limits its menu comments so that menus fit on a
2653 24×80 alphanumeric display.
2655 A new web page tz-how-to.html. (Thanks to Bill Seymour.)
2657 In the Theory file, the description of possible time zone abbreviations in
2658 tzdata has been cleaned up, as the old description was unclear and
2659 inconsistent. (Thanks to Alain Mouette for reporting the problem.)
2662 Release 2016a - 2016-01-26 23:28:02 -0800
2664 Changes affecting future timestamps
2666 America/Cayman will not observe daylight saving this year after all.
2667 Revert our guess that it would. (Thanks to Matt Johnson.)
2669 Asia/Chita switches from +0800 to +0900 on 2016-03-27 at 02:00.
2670 (Thanks to Alexander Krivenyshev.)
2672 Asia/Tehran now has DST predictions for the year 2038 and later,
2673 to be March 21 00:00 to September 21 00:00. This is likely better
2674 than predicting no DST, albeit off by a day every now and then.
2676 Changes affecting past and future timestamps
2678 America/Metlakatla switched from PST all year to AKST/AKDT on
2679 2015-11-01 at 02:00. (Thanks to Steffen Thorsen.)
2681 America/Santa_Isabel has been removed, and replaced with a
2682 backward compatibility link to America/Tijuana. Its contents were
2683 apparently based on a misreading of Mexican legislation.
2685 Changes affecting past timestamps
2687 Asia/Karachi's two transition times in 2002 were off by a minute.
2688 (Thanks to Matt Johnson.)
2690 Changes affecting build procedure
2692 An installer can now combine leap seconds with use of the backzone file,
2693 e.g., with 'make PACKRATDATA=backzone REDO=posix_right zones'.
2694 The old 'make posix_packrat' rule is now marked as obsolescent.
2695 (Thanks to Ian Abbott for an initial implementation.)
2697 Changes affecting documentation and commentary
2699 A new file LICENSE makes it easier to see that the code and data
2700 are mostly public-domain. (Thanks to James Knight.) The three
2701 non-public-domain files now use the current (3-clause) BSD license
2702 instead of older versions of that license.
2704 tz-link.htm mentions the BDE library (thanks to Andrew Paprocki),
2705 CCTZ (thanks to Tim Parenti), TimeJones.com, and has a new section
2706 on editing tz source files (with a mention of Sublime zoneinfo,
2707 thanks to Gilmore Davidson).
2709 The Theory and asia files now mention the 2015 book "The Global
2710 Transformation of Time, 1870-1950", and cite a couple of reviews.
2712 The America/Chicago entry now documents the informal use of US
2713 central time in Fort Pierre, South Dakota. (Thanks to Rick
2714 McDermid, Matt Johnson, and Steve Jones.)
2717 Release 2015g - 2015-10-01 00:39:51 -0700
2719 Changes affecting future timestamps
2721 Turkey's 2015 fall-back transition is scheduled for Nov. 8, not Oct. 25.
2724 Norfolk moves from +1130 to +1100 on 2015-10-04 at 02:00 local time.
2725 (Thanks to Alexander Krivenyshev.)
2727 Fiji's 2016 fall-back transition is scheduled for January 17, not 24.
2728 (Thanks to Ken Rylander.)
2730 Fort Nelson, British Columbia will not fall back on 2015-11-01. It has
2731 effectively been on MST (-0700) since it advanced its clocks on 2015-03-08.
2732 New zone America/Fort_Nelson. (Thanks to Matt Johnson.)
2734 Changes affecting past timestamps
2736 Norfolk observed DST from 1974-10-27 02:00 to 1975-03-02 02:00.
2738 Changes affecting code
2740 localtime no longer mishandles America/Anchorage after 2037.
2741 (Thanks to Bradley White for reporting the bug.)
2743 On hosts with signed 32-bit time_t, localtime no longer mishandles
2744 Pacific/Fiji after 2038-01-16 14:00 UTC.
2746 The localtime module allows the variables 'timezone', 'daylight',
2747 and 'altzone' to be in common storage shared with other modules,
2748 and declares them in case the system <time.h> does not.
2749 (Problems reported by Kees Dekker.)
2751 On platforms with tm_zone, strftime.c now assumes it is not NULL.
2752 This simplifies the code and is consistent with zdump.c.
2753 (Problem reported by Christos Zoulas.)
2755 Changes affecting documentation
2757 The tzfile man page now documents that transition times denote the
2758 starts (not the ends) of the corresponding time periods.
2759 (Ambiguity reported by Bill Seymour.)
2762 Release 2015f - 2015-08-10 18:06:56 -0700
2764 Changes affecting future timestamps
2766 North Korea switches to +0830 on 2015-08-15. (Thanks to Steffen Thorsen.)
2767 The abbreviation remains "KST". (Thanks to Robert Elz.)
2769 Uruguay no longer observes DST. (Thanks to Steffen Thorsen
2772 Changes affecting past and future timestamps
2774 Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
2775 (Thanks to Roman Tudos.)
2777 Changes affecting data format and code
2779 zic's '-y YEARISTYPE' option is no longer documented. The TYPE
2780 field of a Rule line should now be '-'; the old values 'even',
2781 'odd', 'uspres', 'nonpres', 'nonuspres' were already undocumented.
2782 Although the implementation has not changed, these features do not
2783 work in the default installation, they are not used in the data,
2784 and they are now considered obsolescent.
2786 zic now checks that two rules don't take effect at the same time.
2787 (Thanks to Jon Skeet and Arthur David Olson.) Constraints on
2788 simultaneity are now documented.
2790 The two characters '%z' in a zone format now stand for the UT
2791 offset, e.g., '-07' for seven hours behind UT and '+0530' for
2792 five hours and thirty minutes ahead. This better supports time
2793 zone abbreviations conforming to POSIX.1-2001 and later.
2795 Changes affecting installed data files
2797 Comments for America/Halifax and America/Glace_Bay have been improved.
2798 (Thanks to Brian Inglis.)
2800 Data entries have been simplified for Atlantic/Canary, Europe/Simferopol,
2801 Europe/Sofia, and Europe/Tallinn. This yields slightly smaller
2802 installed data files for Europe/Simferopol and Europe/Tallinn.
2803 It does not affect timestamps. (Thanks to Howard Hinnant.)
2805 Changes affecting code
2807 zdump and zic no longer warn about valid time zone abbreviations
2810 Some Visual Studio 2013 warnings have been suppressed.
2811 (Thanks to Kees Dekker.)
2813 'date' no longer sets the time of day and its -a, -d, -n and -t
2814 options have been removed. Long obsolescent, the implementation
2815 of these features had porting problems. Builders no longer need
2816 to configure HAVE_ADJTIME, HAVE_SETTIMEOFDAY, or HAVE_UTMPX_H.
2817 (Thanks to Kees Dekker for pointing out the problem.)
2819 Changes affecting documentation
2821 The Theory file mentions naming issues earlier, as these seem to be
2822 poorly publicized (thanks to Gilmore Davidson for reporting the problem).
2824 tz-link.htm mentions Time Zone Database Parser (thanks to Howard Hinnant).
2826 Mention that Herbert Samuel introduced the term "Summer Time".
2829 Release 2015e - 2015-06-13 10:56:02 -0700
2831 Changes affecting future timestamps
2833 Morocco will suspend DST from 2015-06-14 03:00 through 2015-07-19 02:00,
2834 not 06-13 and 07-18 as we had guessed. (Thanks to Milamber.)
2836 Assume Cayman Islands will observe DST starting next year, using US rules.
2837 Although it isn't guaranteed, it is the most likely.
2839 Changes affecting data format
2841 The file 'iso3166.tab' now uses UTF-8, so that its entries can better
2842 spell the names of Åland Islands, Côte d'Ivoire, and Réunion.
2844 Changes affecting code
2846 When displaying data, tzselect converts it to the current locale's
2847 encoding if the iconv command works. (Problem reported by random832.)
2849 tzselect no longer mishandles Dominica, fixing a bug introduced
2850 in Release 2014f. (Problem reported by Owen Leibman.)
2852 zic -l no longer fails when compiled with -DTZDEFAULT=\"/etc/localtime\".
2853 This fixes a bug introduced in Release 2014f.
2854 (Problem reported by Leonardo Chiquitto.)
2857 Release 2015d - 2015-04-24 08:09:46 -0700
2859 Changes affecting future timestamps
2861 Egypt will not observe DST in 2015 and will consider canceling it
2862 permanently. For now, assume no DST indefinitely.
2863 (Thanks to Ahmed Nazmy and Tim Parenti.)
2865 Changes affecting past timestamps
2867 America/Whitehorse switched from UT -09 to -08 on 1967-05-28, not
2868 1966-07-01. Also, Yukon's time zone history is documented better.
2869 (Thanks to Brian Inglis and Dennis Ferguson.)
2871 Change affecting past and future time zone abbreviations
2873 The abbreviations for Hawaii-Aleutian standard and daylight times
2874 have been changed from HAST/HADT to HST/HDT, as per US Government
2875 Printing Office style. This affects only America/Adak since 1983,
2876 as America/Honolulu was already using the new style.
2878 Changes affecting code
2880 zic has some minor performance improvements.
2883 Release 2015c - 2015-04-11 08:55:55 -0700
2885 Changes affecting future timestamps
2887 Egypt's spring-forward transition is at 24:00 on April's last Thursday,
2888 not 00:00 on April's last Friday. 2015's transition will therefore be on
2889 Thursday, April 30 at 24:00, not Friday, April 24 at 00:00. Similar fixes
2890 apply to 2026, 2037, 2043, etc. (Thanks to Steffen Thorsen.)
2892 Changes affecting past timestamps
2894 The following changes affect some pre-1991 Chile-related timestamps
2895 in America/Santiago, Antarctica/Palmer, and Pacific/Easter.
2897 The 1910 transition was January 10, not January 1.
2899 The 1918 transition was September 10, not September 1.
2901 The UT -04 time observed from 1932 to 1942 is now considered to
2902 be standard time, not year-round DST.
2904 Santiago observed DST (UT -03) from 1946-07-15 through
2905 1946-08-31, then reverted to standard time, then switched to -05
2908 Assume transitions before 1968 were at 00:00, since we have no data
2911 The spring 1988 transition was 1988-10-09, not 1988-10-02.
2912 The fall 1990 transition was 1990-03-11, not 1990-03-18.
2914 Assume no UT offset change for Pacific/Easter on 1890-01-01,
2915 and omit all transitions on Pacific/Easter from 1942 through 1946
2916 since we have no data suggesting that they existed.
2918 One more zone has been turned into a link, as it differed
2919 from an existing zone only for older timestamps. As usual,
2920 this change affects UT offsets in pre-1970 timestamps only.
2921 The zone's old contents have been moved to the 'backzone' file.
2922 The affected zone is America/Montreal.
2924 Changes affecting commentary
2926 Mention the TZUpdater tool.
2928 Mention "The Time Now". (Thanks to Brandon Ramsey.)
2931 Release 2015b - 2015-03-19 23:28:11 -0700
2933 Changes affecting future timestamps
2935 Mongolia will start observing DST again this year, from the last
2936 Saturday in March at 02:00 to the last Saturday in September at 00:00.
2937 (Thanks to Ganbold Tsagaankhuu.)
2939 Palestine will start DST on March 28, not March 27. Also,
2940 correct the fall 2014 transition from September 26 to October 24.
2941 Adjust future predictions accordingly. (Thanks to Steffen Thorsen.)
2943 Changes affecting past timestamps
2945 The 1982 zone shift in Pacific/Easter has been corrected, fixing a 2015a
2946 regression. (Thanks to Stuart Bishop for reporting the problem.)
2948 Some more zones have been turned into links, when they differed
2949 from existing zones only for older timestamps. As usual,
2950 these changes affect UT offsets in pre-1970 timestamps only.
2951 Their old contents have been moved to the 'backzone' file.
2952 The affected zones are: America/Antigua, America/Cayman,
2953 Pacific/Midway, and Pacific/Saipan.
2955 Changes affecting time zone abbreviations
2957 Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD".
2960 Changes affecting code
2962 Fix integer overflow bug in reference 'mktime' implementation.
2963 (Problem reported by Jörg Richter.)
2965 Allow -Dtime_tz=time_t compilations, and allow -Dtime_tz=... libraries
2966 to be used in the same executable as standard-library time_t functions.
2967 (Problems reported by Bradley White.)
2969 Changes affecting commentary
2971 Cite the recent Mexican decree changing Quintana Roo's time zone.
2972 (Thanks to Carlos Raúl Perasso.)
2974 Likewise for the recent Chilean decree. (Thanks to Eduardo Romero Urra.)
2976 Update info about Mars time.
2979 Release 2015a - 2015-01-29 22:35:20 -0800
2981 Changes affecting future timestamps
2983 The Mexican state of Quintana Roo, represented by America/Cancun,
2984 will shift from Central Time with DST to Eastern Time without DST
2985 on 2015-02-01 at 02:00. (Thanks to Steffen Thorsen and Gwillim Law.)
2987 Chile will not change clocks in April or thereafter; its new standard time
2988 will be its old daylight saving time. This affects America/Santiago,
2989 Pacific/Easter, and Antarctica/Palmer. (Thanks to Juan Correa.)
2991 New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
2992 (Thanks to Tim Parenti.)
2994 Changes affecting past timestamps
2996 Iceland observed DST in 1919 and 1921, and its 1939 fallback
2997 transition was Oct. 29, not Nov. 29. Remove incorrect data from
2998 Shanks about time in Iceland between 1837 and 1908.
3000 Some more zones have been turned into links, when they differed
3001 from existing zones only for older timestamps. As usual,
3002 these changes affect UT offsets in pre-1970 timestamps only.
3003 Their old contents have been moved to the 'backzone' file.
3004 The affected zones are: Asia/Aden, Asia/Bahrain, Asia/Kuwait,
3007 Changes affecting code
3009 tzalloc now scrubs time zone abbreviations compatibly with the way
3010 that tzset always has, by replacing invalid bytes with '_' and by
3011 shortening too-long abbreviations.
3013 tzselect ports to POSIX awk implementations, no longer mishandles
3014 POSIX TZ settings when GNU awk is used, and reports POSIX TZ
3015 settings to the user. (Thanks to Stefan Kuhn.)
3017 Changes affecting build procedure
3019 'make check' now checks for links to links in the data.
3020 One such link (for Africa/Asmera) has been fixed.
3021 (Thanks to Stephen Colebourne for pointing out the problem.)
3023 Changes affecting commentary
3025 The leapseconds file commentary now mentions the expiration date.
3026 (Problem reported by Martin Burnicki.)
3028 Update Mexican Library of Congress URL.
3031 Release 2014j - 2014-11-10 17:37:11 -0800
3033 Changes affecting current and future timestamps
3035 Turks & Caicos' switch from US eastern time to UT -04 year-round
3036 did not occur on 2014-11-02 at 02:00. It's currently scheduled
3037 for 2015-11-01 at 02:00. (Thanks to Chris Walton.)
3039 Changes affecting past timestamps
3041 Many pre-1989 timestamps have been corrected for Asia/Seoul and
3042 Asia/Pyongyang, based on sources for the Korean-language Wikipedia
3043 entry for time in Korea. (Thanks to Sanghyuk Jung.) Also, no
3044 longer guess that Pyongyang mimicked Seoul time after World War II,
3045 as this is politically implausible.
3047 Some more zones have been turned into links, when they differed
3048 from existing zones only for older timestamps. As usual,
3049 these changes affect UT offsets in pre-1970 timestamps only.
3050 Their old contents have been moved to the 'backzone' file.
3051 The affected zones are: Africa/Addis_Ababa, Africa/Asmara,
3052 Africa/Dar_es_Salaam, Africa/Djibouti, Africa/Kampala,
3053 Africa/Mogadishu, Indian/Antananarivo, Indian/Comoro, and
3056 Changes affecting commentary
3058 The commentary is less enthusiastic about Shanks as a source,
3059 and is more careful to distinguish UT from UTC.
3062 Release 2014i - 2014-10-21 22:04:57 -0700
3064 Changes affecting future timestamps
3066 Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
3067 (Thanks to Ken Rylander for the heads-up.) Guess that future
3068 years will use a similar pattern.
3070 A new Zone Pacific/Bougainville, for the part of Papua New Guinea
3071 that plans to switch from UT +10 to +11 on 2014-12-28 at 02:00.
3072 (Thanks to Kiley Walbom for the heads-up.)
3074 Changes affecting time zone abbreviations
3076 Since Belarus is not changing its clocks even though Moscow is,
3077 the time zone abbreviation in Europe/Minsk is changing from FET
3078 to its more traditional value MSK on 2014-10-26 at 01:00.
3079 (Thanks to Alexander Bokovoy for the heads-up about Belarus.)
3081 The new abbreviation IDT stands for the pre-1976 use of UT +08 in
3082 Indochina, to distinguish it better from ICT (+07).
3084 Changes affecting past timestamps
3086 Many timestamps have been corrected for Asia/Ho_Chi_Minh before 1976
3087 (thanks to Trần Ngọc Quân for an indirect pointer to Trần Tiến Bình's
3088 authoritative book). Asia/Ho_Chi_Minh has been added to
3089 zone1970.tab, to give tzselect users in Vietnam two choices,
3090 since north and south Vietnam disagreed after our 1970 cutoff.
3092 Asia/Phnom_Penh and Asia/Vientiane have been turned into links, as
3093 they differed from existing zones only for older timestamps. As
3094 usual, these changes affect pre-1970 timestamps only. Their old
3095 contents have been moved to the 'backzone' file.
3097 Changes affecting code
3099 The time-related library functions now set errno on failure, and
3100 some crashes in the new tzalloc-related library functions have
3101 been fixed. (Thanks to Christos Zoulas for reporting most of
3102 these problems and for suggesting fixes.)
3104 If USG_COMPAT is defined and the requested timestamp is standard time,
3105 the tz library's localtime and mktime functions now set the extern
3106 variable timezone to a value appropriate for that timestamp; and
3107 similarly for ALTZONE, daylight saving time, and the altzone variable.
3108 This change is a companion to the tzname change in 2014h, and is
3109 designed to make timezone and altzone more compatible with tzname.
3111 The tz library's functions now set errno to EOVERFLOW if they fail
3112 because the result cannot be represented. ctime and ctime_r now
3113 return NULL and set errno when a timestamp is out of range, rather
3114 than having undefined behavior.
3116 Some bugs associated with the new 2014g functions have been fixed.
3117 This includes a bug that largely incapacitated the new functions
3118 time2posix_z and posix2time_z. (Thanks to Christos Zoulas.)
3119 It also includes some uses of uninitialized variables after tzalloc.
3120 The new code uses the standard type 'ssize_t', which the Makefile
3121 now gives porting advice about.
3123 Changes affecting commentary
3125 Updated URLs for NRC Canada (thanks to Matt Johnson and Brian Inglis).
3128 Release 2014h - 2014-09-25 18:59:03 -0700
3130 Changes affecting past timestamps
3132 America/Jamaica's 1974 spring-forward transition was Jan. 6, not Apr. 28.
3134 Shanks says Asia/Novokuznetsk switched from LMT (not "NMT") on 1924-05-01,
3135 not 1920-01-06. The old entry was based on a misinterpretation of Shanks.
3137 Some more zones have been turned into links, when they differed
3138 from existing zones only for older timestamps. As usual,
3139 these changes affect UT offsets in pre-1970 timestamps only.
3140 Their old contents have been moved to the 'backzone' file.
3141 The affected zones are: Africa/Blantyre, Africa/Bujumbura,
3142 Africa/Gaborone, Africa/Harare, Africa/Kigali, Africa/Lubumbashi,
3143 Africa/Lusaka, Africa/Maseru, and Africa/Mbabane.
3145 Changes affecting code
3147 zdump -V and -v now output gmtoff= values on all platforms,
3148 not merely on platforms defining TM_GMTOFF.
3150 The tz library's localtime and mktime functions now set tzname to a value
3151 appropriate for the requested timestamp, and zdump now uses this
3152 on platforms not defining TM_ZONE, fixing a 2014g regression.
3153 (Thanks to Tim Parenti for reporting the problem.)
3155 The tz library no longer sets tzname if localtime or mktime fails.
3157 zdump -c no longer mishandles transitions near year boundaries.
3158 (Thanks to Tim Parenti for reporting the problem.)
3160 An access to uninitialized data has been fixed.
3161 (Thanks to Jörg Richter for reporting the problem.)
3163 When THREAD_SAFE is defined, the code ports to the C11 memory model.
3164 A memory leak has been fixed if ALL_STATE and THREAD_SAFE are defined
3165 and two threads race to initialize data used by gmtime-like functions.
3166 (Thanks to Andy Heninger for reporting the problems.)
3168 Changes affecting build procedure
3170 'make check' now checks better for properly sorted data.
3172 Changes affecting documentation and commentary
3174 zdump's gmtoff=N output is now documented, and its isdst=D output
3175 is now documented to possibly output D values other than 0 or 1.
3177 zdump -c's treatment of years is now documented to use the
3178 Gregorian calendar and Universal Time without leap seconds,
3179 and its behavior at cutoff boundaries is now documented better.
3180 (Thanks to Arthur David Olson and Tim Parenti for reporting the problems.)
3182 Programs are now documented to use the proleptic Gregorian calendar.
3183 (Thanks to Alan Barrett for the suggestion.)
3185 Fractional-second GMT offsets have been documented for civil time
3186 in 19th-century Chennai, Jakarta, and New York.
3189 Release 2014g - 2014-08-28 12:31:23 -0700
3191 Changes affecting future timestamps
3193 Turks & Caicos is switching from US eastern time to UT -04
3194 year-round, modeled as a switch on 2014-11-02 at 02:00.
3195 [As noted in 2014j, this switch was later delayed.]
3197 Changes affecting past timestamps
3199 Time in Russia or the USSR before 1926 or so has been corrected by
3200 a few seconds in the following zones: Asia/Irkutsk,
3201 Asia/Krasnoyarsk, Asia/Omsk, Asia/Samarkand, Asia/Tbilisi,
3202 Asia/Vladivostok, Asia/Yakutsk, Europe/Riga, Europe/Samara. For
3203 Asia/Yekaterinburg the correction is a few minutes. (Thanks to
3204 Vladimir Karpinsky.)
3206 The Portuguese decree of 1911-05-26 took effect on 1912-01-01.
3207 This affects 1911 timestamps in Africa/Bissau, Africa/Luanda,
3208 Atlantic/Azores, and Atlantic/Madeira. Also, Lisbon's pre-1912
3209 GMT offset was -0:36:45 (rounded from -0:36:44.68), not -0:36:32.
3210 (Thanks to Stephen Colebourne for pointing to the decree.)
3212 Asia/Dhaka ended DST on 2009-12-31 at 24:00, not 23:59.
3214 A new file 'backzone' contains data which may appeal to
3215 connoisseurs of old timestamps, although it is out of scope for
3216 the tz database, is often poorly sourced, and contains some data
3217 that is known to be incorrect. The new file is not recommended
3218 for ordinary use and its entries are not installed by default.
3219 (Thanks to Lester Caine for the high-quality Jersey, Guernsey, and
3220 Isle of Man entries.)
3222 Some more zones have been turned into links, when they differed
3223 from existing zones only for older timestamps. As usual,
3224 these changes affect UT offsets in pre-1970 timestamps only.
3225 Their old contents have been moved to the 'backzone' file.
3226 The affected zones are: Africa/Bangui, Africa/Brazzaville,
3227 Africa/Douala, Africa/Kinshasa, Africa/Libreville, Africa/Luanda,
3228 Africa/Malabo, Africa/Niamey, and Africa/Porto-Novo.
3230 Changes affecting code
3232 Unless NETBSD_INSPIRED is defined to 0, the tz library now
3233 supplies functions for creating and using objects that represent
3234 timezones. The new functions are tzalloc, tzfree, localtime_rz,
3235 mktime_z, and (if STD_INSPIRED is also defined) posix2time_z and
3236 time2posix_z. They are intended for performance: for example,
3237 localtime_rz (unlike localtime_r) is trivially thread-safe without
3238 locking. (Thanks to Christos Zoulas for proposing NetBSD-inspired
3239 functions, and to Alan Barrett and Jonathan Lennox for helping to
3242 zdump now builds with the tz library unless USE_LTZ is defined to 0,
3243 This lets zdump use tz features even if the system library lacks them.
3244 To build zdump with the system library, use 'make CFLAGS=-DUSE_LTZ=0
3245 TZDOBJS=zdump.o CHECK_TIME_T_ALTERNATIVES='.
3247 zdump now uses localtime_rz if available, as it's significantly faster,
3248 and it can help zdump better diagnose invalid timezone names.
3249 Define HAVE_LOCALTIME_RZ to 0 to suppress this. HAVE_LOCALTIME_RZ
3250 defaults to 1 if NETBSD_INSPIRED && USE_LTZ. When localtime_rz is
3251 not available, zdump now uses localtime_r and tzset if available,
3252 as this is a bit cleaner and faster than plain localtime. Compile
3253 with -DHAVE_LOCALTIME_R=0 and/or -DHAVE_TZSET=0 if your system
3254 lacks these two functions.
3256 If THREAD_SAFE is defined to 1, the tz library is now thread-safe.
3257 Although not needed for tz's own applications, which are single-threaded,
3258 this supports POSIX better if the tz library is used in multithreaded apps.
3260 Some crashes have been fixed when zdump or the tz library is given
3261 invalid or outlandish input.
3263 The tz library no longer mishandles leap seconds on platforms with
3264 unsigned time_t in timezones that lack ordinary transitions after 1970.
3266 The tz code now attempts to infer TM_GMTOFF and TM_ZONE if not
3267 already defined, to make it easier to configure on common platforms.
3268 Define NO_TM_GMTOFF and NO_TM_ZONE to suppress this.
3270 Unless the new macro UNINIT_TRAP is defined to 1, the tz code now
3271 assumes that reading uninitialized memory yields garbage values
3272 but does not cause other problems such as traps.
3274 If TM_GMTOFF is defined and UNINIT_TRAP is 0, mktime is now
3275 more likely to guess right for ambiguous timestamps near
3276 transitions where tm_isdst does not change.
3278 If HAVE_STRFTIME_L is defined to 1, the tz library now defines
3279 strftime_l for compatibility with recent versions of POSIX.
3280 Only the C locale is supported, though. HAVE_STRFTIME_L defaults
3281 to 1 on recent POSIX versions, and to 0 otherwise.
3283 tzselect -c now uses a hybrid distance measure that works better
3284 in Africa. (Thanks to Alan Barrett for noting the problem.)
3286 The C source code now ports to NetBSD when GCC_DEBUG_FLAGS is used,
3287 or when time_tz is defined.
3289 When HAVE_UTMPX_H is set the 'date' command now builds on systems
3290 whose <utmpx.h> file does not define WTMPX_FILE, and when setting
3291 the date it updates the wtmpx file if _PATH_WTMPX is defined.
3292 This affects GNU/Linux and similar systems.
3294 For easier maintenance later, some C code has been simplified,
3295 some lint has been removed, and the code has been tweaked so that
3296 plain 'make' is more likely to work.
3298 The C type 'bool' is now used for boolean values, instead of 'int'.
3300 The long-obsolete LOCALE_HOME code has been removed.
3302 The long-obsolete 'gtime' function has been removed.
3304 Changes affecting build procedure
3306 'zdump' no longer links in ialloc.o, as it's not needed.
3308 'make check_time_t_alternatives' no longer assumes GNU diff.
3310 Changes affecting distribution tarballs
3312 The files checktab.awk and zoneinfo2tdf.pl are now distributed in
3313 the tzdata tarball instead of the tzcode tarball, since they help
3314 maintain the data. The NEWS and Theory files are now also
3315 distributed in the tzdata tarball, as they're relevant for data.
3316 (Thanks to Alan Barrett for pointing this out.) Also, the
3317 leapseconds.awk file is no longer distributed in the tzcode
3318 tarball, since it belongs in the tzdata tarball (where 2014f
3319 inadvertently also distributed it).
3321 Changes affecting documentation and commentary
3323 A new file CONTRIBUTING is distributed. (Thanks to Tim Parenti for
3324 suggesting a CONTRIBUTING file, and to Tony Finch and Walter Harms
3327 The man pages have been updated to use function prototypes,
3328 to document thread-safe variants like localtime_r, and to document
3329 the NetBSD-inspired functions tzalloc, tzfree, localtime_rz, and
3332 The fields in Link lines have been renamed to be more descriptive
3333 and more like the parameters of 'ln'. LINK-FROM has become TARGET,
3334 and LINK-TO has become LINK-NAME.
3336 tz-link.htm mentions the IETF's tzdist working group; Windows
3337 Runtime etc. (thanks to Matt Johnson); and HP-UX's tztab.
3339 Some broken URLs have been fixed in the commentary. (Thanks to
3342 Commentary about Philippines DST has been updated, and commentary
3343 on pre-1970 time in India has been added.
3346 Release 2014f - 2014-08-05 17:42:36 -0700
3348 Changes affecting future timestamps
3350 Russia will subtract an hour from most of its time zones on 2014-10-26
3351 at 02:00 local time. (Thanks to Alexander Krivenyshev.)
3352 There are a few exceptions: Magadan Oblast (Asia/Magadan) and Zabaykalsky
3353 Krai are subtracting two hours; conversely, Chukotka Autonomous Okrug
3354 (Asia/Anadyr), Kamchatka Krai (Asia/Kamchatka), Kemerovo Oblast
3355 (Asia/Novokuznetsk), and the Samara Oblast and the Udmurt Republic
3356 (Europe/Samara) are not changing their clocks. The changed zones are
3357 Europe/Kaliningrad, Europe/Moscow, Europe/Simferopol, Europe/Volgograd,
3358 Asia/Yekaterinburg, Asia/Omsk, Asia/Novosibirsk, Asia/Krasnoyarsk,
3359 Asia/Irkutsk, Asia/Yakutsk, Asia/Vladivostok, Asia/Khandyga,
3360 Asia/Sakhalin, and Asia/Ust-Nera; Asia/Magadan will have two hours
3361 subtracted; and Asia/Novokuznetsk's time zone abbreviation is affected,
3362 but not its UTC offset. Two zones are added: Asia/Chita (split
3363 from Asia/Yakutsk, and also with two hours subtracted) and
3364 Asia/Srednekolymsk (split from Asia/Magadan, but with only one hour
3365 subtracted). (Thanks to Tim Parenti for much of the above.)
3367 Changes affecting time zone abbreviations
3369 Australian eastern time zone abbreviations are now AEST/AEDT not EST,
3370 and similarly for the other Australian zones. That is, for eastern
3371 standard and daylight saving time the abbreviations are AEST and AEDT
3372 instead of the former EST for both; similarly, ACST/ACDT, ACWST/ACWDT,
3373 and AWST/AWDT are now used instead of the former CST, CWST, and WST.
3374 This change does not affect UT offsets, only time zone abbreviations.
3375 (Thanks to Rich Tibbett and many others.)
3377 Asia/Novokuznetsk shifts from NOVT to KRAT (remaining on UT +07)
3378 effective 2014-10-26 at 02:00 local time.
3380 The time zone abbreviation for Xinjiang Time (observed in Ürümqi)
3381 has been changed from URUT to XJT. (Thanks to Luther Ma.)
3383 Prefer MSK/MSD for Moscow time in Russia, even in other cities.
3384 Similarly, prefer EET/EEST for eastern European time in Russia.
3386 Change time zone abbreviations in (western) Samoa to use "ST" and
3387 "DT" suffixes, as this is more likely to match common practice.
3388 Prefix "W" to (western) Samoa time when its standard-time offset
3389 disagrees with that of American Samoa.
3391 America/Metlakatla now uses PST, not MeST, to abbreviate its time zone.
3393 Time zone abbreviations have been updated for Japan's two time
3394 zones used 1896-1937. JWST now stands for Western Standard
3395 Time, and JCST for Central Standard Time (formerly this was CJT).
3396 These abbreviations are now used for time in Korea, Taiwan,
3397 and Sakhalin while controlled by Japan.
3399 Changes affecting past timestamps
3401 China's five zones have been simplified to two, since the post-1970
3402 differences in the other three seem to have been imaginary. The
3403 zones Asia/Harbin, Asia/Chongqing, and Asia/Kashgar have been
3404 removed; backwards-compatibility links still work, albeit with
3405 different behaviors for timestamps before May 1980. Asia/Urumqi's
3406 1980 transition to UT +08 has been removed, so that it is now at
3407 +06 and not +08. (Thanks to Luther Ma and to Alois Treindl;
3408 Treindl sent helpful translations of two papers by Guo Qingsheng.)
3410 Some zones have been turned into links, when they differed from existing
3411 zones only for older UT offsets where data entries were likely invented.
3412 These changes affect UT offsets in pre-1970 timestamps only. This is
3413 similar to the change in release 2013e, except this time for western
3414 Africa. The affected zones are: Africa/Bamako, Africa/Banjul,
3415 Africa/Conakry, Africa/Dakar, Africa/Freetown, Africa/Lome,
3416 Africa/Nouakchott, Africa/Ouagadougou, Africa/Sao_Tome, and
3417 Atlantic/St_Helena. This also affects the backwards-compatibility
3418 link Africa/Timbuktu. (Thanks to Alan Barrett, Stephen Colebourne,
3419 Tim Parenti, and David Patte for reporting problems in earlier
3420 versions of this change.)
3422 Asia/Shanghai's pre-standard-time UT offset has been changed from
3423 8:05:57 to 8:05:43, the location of Xujiahui Observatory. Its
3424 transition to standard time has been changed from 1928 to 1901.
3426 Asia/Taipei switched to JWST on 1896-01-01, then to JST on 1937-10-01,
3427 then to CST on 1945-09-21 at 01:00, and did not observe DST in 1945.
3428 In 1946 it observed DST from 05-15 through 09-30; in 1947
3429 from 04-15 through 10-31; and in 1979 from 07-01 through 09-30.
3430 (Thanks to Yu-Cheng Chuang.)
3432 Asia/Riyadh's transition to standard time is now 1947-03-14, not 1950.
3434 Europe/Helsinki's 1942 fall-back transition was 10-04 at 01:00, not
3435 10-03 at 00:00. (Thanks to Konstantin Hyppönen.)
3437 Pacific/Pago_Pago has been changed from UT -11:30 to -11 for the
3438 period from 1911 to 1950.
3440 Pacific/Chatham has been changed to New Zealand standard time plus
3441 45 minutes for the period before 1957, reflecting a 1956 remark in
3442 the New Zealand parliament.
3444 Europe/Budapest has several pre-1946 corrections: in 1918 the transition
3445 out of DST was on 09-16, not 09-29; in 1919 it was on 11-24, not 09-15; in
3446 1945 it was on 11-01, not 11-03; in 1941 the transition to DST was 04-08
3447 not 04-06 at 02:00; and there was no DST in 1920.
3449 Africa/Accra is now assumed to have observed DST from 1920 through 1935.
3451 Time in Russia before 1927 or so has been corrected by a few seconds in
3452 the following zones: Europe/Moscow, Asia/Irkutsk, Asia/Tbilisi,
3453 Asia/Tashkent, Asia/Vladivostok, Asia/Yekaterinburg, Europe/Helsinki, and
3454 Europe/Riga. Also, Moscow's location has been changed to its Kilometer 0
3455 point. (Thanks to Vladimir Karpinsky for the Moscow changes.)
3457 Changes affecting data format
3459 A new file 'zone1970.tab' supersedes 'zone.tab' in the installed data.
3460 The new file's extended format allows multiple country codes per zone.
3461 The older file is still installed but is deprecated; its format is
3462 not changing and it will still be distributed for a while, but new
3463 applications should use the new file.
3465 The new file format simplifies maintenance of obscure locations.
3466 To test this, it adds coverage for the Crozet Islands and the
3467 Scattered Islands. (Thanks to Tobias Conradi and Antoine Leca.)
3469 The file 'iso3166.tab' is planned to switch from ASCII to UTF-8.
3470 It is still ASCII now, but commentary about the switch has been added.
3471 The new file 'zone1970.tab' already uses UTF-8.
3473 Changes affecting code
3475 'localtime', 'mktime', etc. now use much less stack space if ALL_STATE
3476 is defined. (Thanks to Elliott Hughes for reporting the problem.)
3478 'zic' no longer mishandles input when ignoring case in locales that
3479 are not compatible with English, e.g., unibyte Turkish locales when
3480 compiled with HAVE_GETTEXT.
3482 Error diagnostics of 'zic' and 'yearistype' have been reworded so that
3483 they no longer use ASCII '-' as if it were a dash.
3485 'zic' now rejects output file names that contain '.' or '..' components.
3486 (Thanks to Tim Parenti for reporting the problem.)
3488 'zic -v' now warns about output file names that do not follow
3489 POSIX rules, or that contain a digit or '.'. (Thanks to Arthur
3490 David Olson for starting the ball rolling on this.)
3492 Some lint has been removed when using GCC_DEBUG_FLAGS with GCC 4.9.0.
3494 Changes affecting build procedure
3496 'zic' no longer links in localtime.o and asctime.o, as they're not needed.
3497 (Thanks to John Cochran.)
3499 Changes affecting documentation and commentary
3501 The 'Theory' file documents legacy names, the longstanding
3502 exceptions to the POSIX-inspired file name rules.
3504 The 'zic' documentation clarifies the role of time types when
3505 interpreting dates. (Thanks to Arthur David Olson.)
3507 Documentation and commentary now prefer UTF-8 to US-ASCII,
3508 allowing the use of proper accents in foreign words and names.
3509 Code and data have not changed because of this. (Thanks to
3510 Garrett Wollman, Ian Abbott, and Guy Harris for helping to debug
3513 Non-HTML documentation and commentary now use plain-text URLs instead of
3514 HTML insertions, and are more consistent about bracketing URLs when they
3515 are not already surrounded by white space. (Thanks to suggestions by
3518 There is new commentary about Xujiahui Observatory, the five time-zone
3519 project in China from 1918 to 1949, timekeeping in Japanese-occupied
3520 Shanghai, and Tibet Time in the 1950s. The sharp-eyed can spot the
3521 warlord Jin Shuren in the data.
3523 Commentary about the coverage of each Russian zone has been standardized.
3524 (Thanks to Tim Parenti.)
3526 There is new commentary about contemporary timekeeping in Ethiopia.
3528 Obsolete comments about a 2007 proposal for DST in Kuwait has been removed.
3530 There is new commentary about time in Poland in 1919.
3532 Proper credit has been given to DST inventor George Vernon Hudson.
3534 Commentary about time in Metlakatla, AK and Resolute, NU has been
3535 improved, with a new source for the former.
3537 In zone.tab, Pacific/Easter no longer mentions Salas y Gómez, as it
3540 Commentary about permanent Antarctic bases has been updated.
3542 Several typos have been corrected. (Thanks to Tim Parenti for
3543 contributing some of these fixes.)
3545 tz-link.htm now mentions the JavaScript libraries Moment Timezone,
3546 TimezoneJS.Date, Walltime-js, and Timezone. (Thanks to a heads-up
3547 from Matt Johnson.) Also, it mentions the Go 'latlong' package.
3548 (Thanks to a heads-up from Dirkjan Ochtman.)
3550 The files usno1988, usno1989, usno1989a, usno1995, usno1997, and usno1998
3551 have been removed. These obsolescent US Naval Observatory entries were no
3552 longer helpful for maintenance. (Thanks to Tim Parenti for the suggestion.)
3555 Release 2014e - 2014-06-12 21:53:52 -0700
3557 Changes affecting near-future timestamps
3559 Egypt's 2014 Ramadan-based transitions are June 26 and July 31 at 24:00.
3560 (Thanks to Imed Chihi.) Guess that from 2015 on Egypt will temporarily
3561 switch to standard time at 24:00 the last Thursday before Ramadan, and
3562 back to DST at 00:00 the first Friday after Ramadan.
3564 Similarly, Morocco's are June 28 at 03:00 and August 2 at 02:00. (Thanks
3565 to Milamber Space Network.) Guess that from 2015 on Morocco will
3566 temporarily switch to standard time at 03:00 the last Saturday before
3567 Ramadan, and back to DST at 02:00 the first Saturday after Ramadan.
3569 Changes affecting past timestamps
3571 The abbreviation "MSM" (Moscow Midsummer Time) is now used instead of
3572 "MSD" for Moscow's double daylight time in summer 1921. Also, a typo
3573 "VLASST" has been repaired to be "VLAST" for Vladivostok summer time
3574 in 1991. (Thanks to Hank W. for reporting the problems.)
3576 Changes affecting commentary
3578 tz-link.htm now cites RFC 7265 for jCal, mentions PTP and the
3579 draft CalDAV extension, updates URLs for TSP, TZInfo, IATA, and
3580 removes stale pointers to World Time Explorer and WORLDTIME.
3583 Release 2014d - 2014-05-27 21:34:40 -0700
3585 Changes affecting code
3587 zic no longer generates files containing timestamps before the Big Bang.
3588 This works around GNOME glib bug 878
3589 <https://gitlab.gnome.org/GNOME/glib/issues/878>
3590 (Thanks to Leonardo Chiquitto for reporting the bug, and to
3591 Arthur David Olson and James Cloos for suggesting improvements to the fix.)
3593 Changes affecting documentation
3595 tz-link.htm now mentions GNOME.
3598 Release 2014c - 2014-05-13 07:44:13 -0700
3600 Changes affecting near-future timestamps
3602 Egypt observes DST starting 2014-05-15 at 24:00.
3603 (Thanks to Ahmad El-Dardiry and Gunther Vermier.)
3604 Details have not been announced, except that DST will not be observed
3605 during Ramadan. Guess that DST will stop during the same Ramadan dates as
3606 Morocco, and that Egypt's future spring and fall transitions will be the
3607 same as 2010 when it last observed DST, namely April's last Friday at
3608 00:00 to September's last Thursday at 23:00 standard time. Also, guess
3609 that Ramadan transitions will be at 00:00 standard time.
3611 Changes affecting code
3613 zic now generates transitions for minimum time values, eliminating guesswork
3614 when handling low-valued timestamps. (Thanks to Arthur David Olson.)
3616 Port to Cygwin sans glibc. (Thanks to Arthur David Olson.)
3618 Changes affecting commentary and documentation
3620 Remove now-confusing comment about Jordan. (Thanks to Oleksii Nochovnyi.)
3623 Release 2014b - 2014-03-24 21:28:50 -0700
3625 Changes affecting near-future timestamps
3627 Crimea switches to Moscow time on 2014-03-30 at 02:00 local time.
3628 (Thanks to Alexander Krivenyshev.) Move its zone.tab entry from UA to RU.
3630 New entry for Troll station, Antarctica. (Thanks to Paul-Inge Flakstad and
3631 Bengt-Inge Larsson.) This is currently an approximation; a better version
3632 will require the zic and localtime fixes mentioned below, and the plan is
3633 to wait for a while until at least the zic fixes propagate.
3635 Changes affecting code
3637 'zic' and 'localtime' no longer reject locations needing four transitions
3638 per year for the foreseeable future. (Thanks to Andrew Main (Zefram).)
3639 Also, 'zic' avoids some unlikely failures due to integer overflow.
3641 Changes affecting build procedure
3643 'make check' now detects Rule lines defined but never used.
3644 The NZAQ rules, an instance of this problem, have been removed.
3646 Changes affecting commentary and documentation
3648 Fix Tuesday/Thursday typo in description of time in Israel.
3649 (Thanks to Bert Katz via Pavel Kharitonov and Mike Frysinger.)
3651 Microsoft Windows 8.1 doesn't support tz database names. (Thanks
3652 to Donald MacQueen.) Instead, the Microsoft Windows Store app
3653 library supports them.
3655 Add comments about Johnston Island time in the 1960s.
3656 (Thanks to Lyle McElhaney.)
3658 Morocco's 2014 DST start will be as predicted.
3659 (Thanks to Sebastien Willemijns.)
3662 Release 2014a - 2014-03-07 23:30:29 -0800
3664 Changes affecting near-future timestamps
3666 Turkey begins DST on 2014-03-31, not 03-30. (Thanks to Faruk Pasin for
3667 the heads-up, and to Tim Parenti for simplifying the update.)
3669 Changes affecting past timestamps
3671 Fiji ended DST on 2014-01-19 at 02:00, not the previously scheduled 03:00.
3672 (Thanks to Steffen Thorsen.)
3674 Ukraine switched from Moscow to Eastern European time on 1990-07-01
3675 (not 1992-01-01), and observed DST during the entire next winter.
3676 (Thanks to Vladimir in Moscow via Alois Treindl.)
3678 In 1988 Israel observed DST from 04-10 to 09-04, not 04-09 to 09-03.
3679 (Thanks to Avigdor Finkelstein.)
3681 Changes affecting code
3683 A uninitialized-storage bug in 'localtime' has been fixed.
3684 (Thanks to Logan Chien.)
3686 Changes affecting the build procedure
3688 The settings for 'make check_web' now default to Ubuntu 13.10.
3690 Changes affecting commentary and documentation
3692 The boundary of the US Pacific time zone is given more accurately.
3693 (Thanks to Alan Mintz.)
3695 Chile's 2014 DST will be as predicted. (Thanks to José Miguel Garrido.)
3697 Paraguay's 2014 DST will be as predicted. (Thanks to Carlos Raúl Perasso.)
3699 Better descriptions of countries with same time zone history as
3700 Trinidad and Tobago since 1970. (Thanks to Alan Barrett for suggestion.)
3702 Several changes affect tz-link.htm, the main web page.
3704 Mention Time.is (thanks to Even Scharning) and WX-now (thanks to
3707 Mention xCal (Internet RFC 6321) and jCal.
3709 Microsoft has some support for tz database names.
3711 CLDR data formats include both XML and JSON.
3713 Mention Maggiolo's map of solar vs standard time.
3714 (Thanks to Arthur David Olson.)
3716 Mention TZ4Net. (Thanks to Matt Johnson.)
3718 Mention the timezone-olson Haskell package.
3720 Mention zeitverschiebung.net. (Thanks to Martin Jäger.)
3722 Remove moribund links to daylight-savings-time.info and to
3723 Simple Timer + Clocks.
3725 Update two links. (Thanks to Oscar van Vlijmen.)
3727 Fix some formatting glitches, e.g., remove random newlines from
3728 abbr elements' title attributes.
3731 Release 2013i - 2013-12-17 07:25:23 -0800
3733 Changes affecting near-future timestamps:
3735 Jordan switches back to standard time at 00:00 on December 20, 2013.
3736 The 2006-2011 transition schedule is planned to resume in 2014.
3737 (Thanks to Steffen Thorsen.)
3739 Changes affecting past timestamps:
3741 In 2004, Cuba began DST on March 28, not April 4.
3742 (Thanks to Steffen Thorsen.)
3744 Changes affecting code
3746 The compile-time flag NOSOLAR has been removed, as nowadays the
3747 benefit of slightly shrinking runtime table size is outweighed by the
3748 cost of disallowing potential future updates that exceed old limits.
3750 Changes affecting documentation and commentary
3752 The files solar87, solar88, and solar89 are no longer distributed.
3753 They were a negative experiment - that is, a demonstration that
3754 tz data can represent solar time only with some difficulty and error.
3755 Their presence in the distribution caused confusion, as Riyadh
3756 civil time was generally not solar time in those years.
3758 tz-link.htm now mentions Noda Time. (Thanks to Matt Johnson.)
3761 Release 2013h - 2013-10-25 15:32:32 -0700
3763 Changes affecting current and future timestamps:
3765 Libya has switched its UT offset back to +02 without DST, instead
3766 of +01 with DST. (Thanks to Even Scharning.)
3768 Western Sahara (Africa/El_Aaiun) uses Morocco's DST rules.
3769 (Thanks to Gwillim Law.)
3771 Changes affecting future timestamps:
3773 Acre and (we guess) western Amazonas will switch from UT -04 to -05
3774 on 2013-11-10. This affects America/Rio_Branco and America/Eirunepe.
3775 (Thanks to Steffen Thorsen.)
3777 Add entries for DST transitions in Morocco in the year 2038.
3778 This avoids some year-2038 glitches introduced in 2013g.
3779 (Thanks to Yoshito Umaoka for reporting the problem.)
3781 Changes affecting API
3783 The 'tzselect' command no longer requires the 'select' command,
3784 and should now work with /bin/sh on more platforms. It also works
3785 around a bug in BusyBox awk before version 1.21.0. (Thanks to
3786 Patrick 'P. J.' McDermott and Alan Barrett.)
3788 Changes affecting code
3790 Fix localtime overflow bugs with 32-bit unsigned time_t.
3792 zdump no longer assumes sscanf returns maximal values on overflow.
3794 Changes affecting the build procedure
3796 The builder can specify which programs to use, if any, instead of
3797 'ar' and 'ranlib', and libtz.a is now built locally before being
3798 installed. (Thanks to Michael Forney.)
3800 A dependency typo in the 'zdump' rule has been fixed.
3801 (Thanks to Andrew Paprocki.)
3803 The Makefile has been simplified by assuming that 'mkdir -p' and 'cp -f'
3804 work as specified by POSIX.2-1992 or later; this is portable nowadays.
3806 'make clean' no longer removes 'leapseconds', since it's
3807 host-independent and is part of the distribution.
3809 The unused makefile macros TZCSRCS, TZDSRCS, DATESRCS have been removed.
3811 Changes affecting documentation and commentary
3813 tz-link.htm now mentions TC TIMEZONE's draft time zone service protocol
3814 (thanks to Mike Douglass) and TimezoneJS.Date (thanks to Jim Fehrle).
3816 Update URLs in tz-link page. Add URLs for Microsoft Windows, since
3817 8.1 introduces tz support. Remove URLs for Tru64 and UnixWare (no
3818 longer maintained) and for old advisories. SOFA now does C.
3820 Release 2013g - 2013-09-30 21:08:26 -0700
3822 Changes affecting current and near-future timestamps
3824 Morocco now observes DST from the last Sunday in March to the last
3825 Sunday in October, not April to September respectively. (Thanks
3826 to Steffen Thorsen.)
3828 Changes affecting 'zic'
3830 'zic' now runs on platforms that lack both hard links and symlinks.
3831 (Thanks to Theo Veenker for reporting the problem, for MinGW.)
3832 Also, fix some bugs on platforms that lack hard links but have symlinks.
3834 'zic -v' again warns that Asia/Tehran has no POSIX environment variable
3835 to predict the far future, fixing a bug introduced in 2013e.
3837 Changes affecting the build procedure
3839 The 'leapseconds' file is again put into the tzdata tarball.
3840 Also, 'leapseconds.awk', so tzdata is self-contained. (Thanks to
3841 Matt Burgess and Ian Abbott.) The timestamps of these and other
3842 dependent files in tarballs are adjusted more consistently.
3844 Changes affecting documentation and commentary
3846 The README file is now part of the data tarball as well as the code.
3847 It now states that files are public domain unless otherwise specified.
3848 (Thanks to Andrew Main (Zefram) for asking for clarifications.)
3849 Its details about the 1989 release moved to a place of honor near
3853 Release 2013f - 2013-09-24 23:37:36 -0700
3855 Changes affecting near-future timestamps
3857 Tocantins will very likely not observe DST starting this spring.
3858 (Thanks to Steffen Thorsen.)
3860 Jordan will likely stay at UT +03 indefinitely, and will not fall
3863 Palestine will fall back at 00:00, not 01:00. (Thanks to Steffen Thorsen.)
3865 Changes affecting API
3867 The types of the global variables 'timezone' and 'altzone' (if present)
3868 have been changed back to 'long'. This is required for 'timezone'
3869 by POSIX, and for 'altzone' by common practice, e.g., Solaris 11.
3870 These variables were originally 'long' in the tz code, but were
3871 mistakenly changed to 'time_t' in 1987; nobody reported the
3872 incompatibility until now. The difference matters on x32, where
3873 'long' is 32 bits and 'time_t' is 64. (Thanks to Elliott Hughes.)
3875 Changes affecting the build procedure
3877 Avoid long strings in leapseconds.awk to work around a mawk bug.
3878 (Thanks to Cyril Baurand.)
3880 Changes affecting documentation and commentary
3882 New file 'NEWS' that contains release notes like this one.
3884 Paraguay's law does not specify DST transition time; 00:00 is customary.
3885 (Thanks to Waldemar Villamayor-Venialbo.)
3887 Minor capitalization fixes.
3889 Changes affecting version-control only
3891 The experimental GitHub repository now contains annotated and
3892 signed tags for recent releases, e.g., '2013e' for Release 2013e.
3893 Releases are tagged starting with 2012e; earlier releases were
3894 done differently, and tags would either not have a simple name or
3895 not exactly match what was released.
3897 'make set-timestamps' is now simpler and a bit more portable.
3900 Release 2013e - 2013-09-19 23:50:04 -0700
3902 Changes affecting near-future timestamps
3904 This year Fiji will start DST on October 27, not October 20.
3905 (Thanks to David Wheeler for the heads-up.) For now, guess that
3906 Fiji will continue to spring forward the Sunday before the fourth
3909 Changes affecting current and future time zone abbreviations
3911 Use WIB/WITA/WIT rather than WIT/CIT/EIT for alphabetic Indonesian
3912 time zone abbreviations since 1932. (Thanks to George Ziegler,
3913 Priyadi Iman Nurcahyo, Zakaria, Jason Grimes, Martin Pitt, and
3914 Benny Lin.) This affects Asia/Dili, Asia/Jakarta, Asia/Jayapura,
3915 Asia/Makassar, and Asia/Pontianak.
3917 Use ART (UT -03, standard time), rather than WARST (also -03, but
3918 daylight saving time) for San Luis, Argentina since 2009.
3920 Changes affecting Godthåb timestamps after 2037 if version mismatch
3922 Allow POSIX-like TZ strings where the transition time's hour can
3923 range from -167 through 167, instead of the POSIX-required 0
3924 through 24. E.g., TZ='FJT-12FJST,M10.3.1/146,M1.3.4/75' for the
3925 new Fiji rules. This is a more compact way to represent
3926 far-future timestamps for America/Godthab, America/Santiago,
3927 Antarctica/Palmer, Asia/Gaza, Asia/Hebron, Asia/Jerusalem,
3928 Pacific/Easter, and Pacific/Fiji. Other zones are unaffected by
3929 this change. (Derived from a suggestion by Arthur David Olson.)
3931 Allow POSIX-like TZ strings where daylight saving time is in
3932 effect all year. E.g., TZ='WART4WARST,J1/0,J365/25' for Western
3933 Argentina Summer Time all year. This supports a more compact way
3934 to represent the 2013d data for America/Argentina/San_Luis.
3935 Because of the change for San Luis noted above this change does not
3936 affect the current data. (Thanks to Andrew Main (Zefram) for
3937 suggestions that improved this change.)
3939 Where these two TZ changes take effect, there is a minor extension
3940 to the tz file format in that it allows new values for the
3941 embedded TZ-format string, and the tz file format version number
3942 has therefore been increased from 2 to 3 as a precaution.
3943 Version-2-based client code should continue to work as before for
3944 all timestamps before 2038. Existing version-2-based client code
3945 (tzcode, GNU/Linux, Solaris) has been tested on version-3-format
3946 files, and typically works in practice even for timestamps after
3947 2037; the only known exception is America/Godthab.
3949 Changes affecting timestamps before 1970
3951 Pacific/Johnston is now a link to Pacific/Honolulu. This corrects
3952 some errors before 1947.
3954 Some zones have been turned into links, when they differ from existing
3955 zones only in older data entries that were likely invented or that
3956 differ only in LMT or transitions from LMT. These changes affect
3957 only timestamps before 1943. The affected zones are:
3958 Africa/Juba, America/Anguilla, America/Aruba, America/Dominica,
3959 America/Grenada, America/Guadeloupe, America/Marigot,
3960 America/Montserrat, America/St_Barthelemy, America/St_Kitts,
3961 America/St_Lucia, America/St_Thomas, America/St_Vincent,
3962 America/Tortola, and Europe/Vaduz. (Thanks to Alois Treindl for
3963 confirming that the old Europe/Vaduz zone was wrong and the new
3964 link is better for WWII-era times.)
3966 Change Kingston Mean Time from -5:07:12 to -5:07:11. This affects
3967 America/Cayman, America/Jamaica and America/Grand_Turk timestamps
3970 Change the UT offset of Bern Mean Time from 0:29:44 to 0:29:46.
3971 This affects Europe/Zurich timestamps from 1853 to 1894. (Thanks
3974 Change the date of the circa-1850 Zurich transition from 1849-09-12
3975 to 1853-07-16, overriding Shanks with data from Messerli about
3976 postal and telegraph time in Switzerland.
3978 Changes affecting time zone abbreviations before 1970
3980 For Asia/Jakarta, use BMT (not JMT) for mean time from 1923 to 1932,
3981 as Jakarta was called Batavia back then.
3983 Changes affecting API
3985 The 'zic' command now outputs a dummy transition when far-future
3986 data can't be summarized using a TZ string, and uses a 402-year
3987 window rather than a 400-year window. For the current data, this
3988 affects only the Asia/Tehran file. It does not affect any of the
3989 timestamps that this file represents, so zdump outputs the same
3990 information as before. (Thanks to Andrew Main (Zefram).)
3992 The 'date' command has a new '-r' option, which lets you specify
3993 the integer time to display, a la FreeBSD.
3995 The 'tzselect' command has two new options '-c' and '-n', which lets you
3996 select a zone based on latitude and longitude.
3998 The 'zic' command's '-v' option now warns about constructs that
3999 require the new version-3 binary file format. (Thanks to Arthur
4000 David Olson for the suggestion.)
4002 Support for floating-point time_t has been removed.
4003 It was always dicey, and POSIX no longer requires it.
4004 (Thanks to Eric Blake for suggesting to the POSIX committee to
4005 remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
4006 Heninger, Arthur David Olson, and Alois Treindl, for reporting
4007 bugs and elucidating some of the corners of the old floating-point
4010 The signatures of 'offtime', 'timeoff', and 'gtime' have been
4011 changed back to the old practice of using 'long' to represent UT
4012 offsets. This had been inadvertently and mistakenly changed to
4013 'int_fast32_t'. (Thanks to Christos Zoulas.)
4015 The code avoids undefined behavior on integer overflow in some
4016 more places, including gmtime, localtime, mktime and zdump.
4018 Changes affecting the zdump utility
4020 zdump now outputs "UT" when referring to Universal Time, not "UTC".
4021 "UTC" does not make sense for timestamps that predate the introduction
4022 of UTC, whereas "UT", a more generic term, does. (Thanks to Steve Allen
4023 for clarifying UT vs UTC.)
4025 Data changes affecting behavior of tzselect and similar programs
4027 Country code BQ is now called the more common name "Caribbean Netherlands"
4028 rather than the more official "Bonaire, St Eustatius & Saba".
4030 Remove from zone.tab the names America/Montreal, America/Shiprock,
4031 and Antarctica/South_Pole, as they are equivalent to existing
4032 same-country-code zones for post-1970 timestamps. The data entries for
4033 these names are unchanged, so the names continue to work as before.
4035 Changes affecting code internals
4037 zic -c now runs way faster on 64-bit hosts when given large numbers.
4039 zic now uses vfprintf to avoid allocating and freeing some memory.
4041 tzselect now computes the list of continents from the data,
4042 rather than have it hard-coded.
4044 Minor changes pacify GCC 4.7.3 and GCC 4.8.1.
4046 Changes affecting the build procedure
4048 The 'leapseconds' file is now generated automatically from a
4049 new file 'leap-seconds.list', which is a copy of
4050 <ftp://ftp.nist.gov/pub/time/leap-seconds.list>
4051 A new source file 'leapseconds.awk' implements this.
4052 The goal is simplification of the future maintenance of 'leapseconds'.
4054 When building the 'posix' or 'right' subdirectories, if the
4055 subdirectory would be a copy of the default subdirectory, it is
4056 now made a symbolic link if that is supported. This saves about
4057 2 MB of file system space.
4059 The links America/Shiprock and Antarctica/South_Pole have been
4060 moved to the 'backward' file. This affects only nondefault builds
4061 that omit 'backward'.
4063 Changes affecting version-control only
4065 .gitignore now ignores 'date'.
4067 Changes affecting documentation and commentary
4069 Changes to the 'tzfile' man page
4071 It now mentions that the binary file format may be extended in
4072 future versions by appending data.
4074 It now refers to the 'zdump' and 'zic' man pages.
4076 Changes to the 'zic' man page
4078 It lists conditions that elicit a warning with '-v'.
4080 It says that the behavior is unspecified when duplicate names
4081 are given, or if the source of one link is the target of another.
4083 Its examples are updated to match the latest data.
4085 The definition of white space has been clarified slightly.
4086 (Thanks to Michael Deckers.)
4088 Changes to the 'Theory' file
4090 There is a new section about the accuracy of the tz database,
4091 describing the many ways that errors can creep in, and
4092 explaining why so many of the pre-1970 timestamps are wrong or
4093 misleading (thanks to Steve Allen, Lester Caine, and Garrett
4094 Wollman for discussions that contributed to this).
4096 The 'Theory' file describes LMT better (this follows a
4097 suggestion by Guy Harris).
4099 It refers to the 2013 edition of POSIX rather than the 2004 edition.
4101 It's mentioned that excluding 'backward' should not affect the
4102 other data, and it suggests at least one zone.tab name per
4103 inhabited country (thanks to Stephen Colebourne).
4105 Some longstanding restrictions on names are documented, e.g.,
4106 'America/New_York' precludes 'America/New_York/Bronx'.
4108 It gives more reasons for the 1970 cutoff.
4110 It now mentions which time_t variants are supported, such as
4111 signed integer time_t. (Thanks to Paul Goyette for reporting
4112 typos in an experimental version of this change.)
4114 (Thanks to Philip Newton for correcting typos in these changes.)
4116 Documentation and commentary is more careful to distinguish UT in
4117 general from UTC in particular. (Thanks to Steve Allen.)
4119 Add a better source for the Zurich 1894 transition.
4120 (Thanks to Pierre-Yves Berger.)
4122 Update shapefile citations in tz-link.htm. (Thanks to Guy Harris.)
4125 Release 2013d - 2013-07-05 07:38:01 -0700
4127 Changes affecting future timestamps:
4129 Morocco's midsummer transitions this year are July 7 and August 10,
4130 not July 9 and August 8. (Thanks to Andrew Paprocki.)
4132 Israel now falls back on the last Sunday of October.
4133 (Thanks to Ephraim Silverberg.)
4135 Changes affecting past timestamps:
4137 Specify Jerusalem's location more precisely; this changes the pre-1880
4140 Changing affecting metadata only:
4142 Fix typos in the entries for country codes BQ and SX.
4144 Changes affecting code:
4146 Rework the code to fix a bug with handling Australia/Macquarie on
4147 32-bit hosts (thanks to Arthur David Olson).
4149 Port to platforms like NetBSD, where time_t can be wider than long.
4151 Add support for testing time_t types other than the system's.
4152 Run 'make check_time_t_alternatives' to try this out.
4153 Currently, the tests fail for unsigned time_t;
4154 this should get fixed at some point.
4156 Changes affecting documentation and commentary:
4158 Deemphasize the significance of national borders.
4160 Update the zdump man page.
4162 Remove obsolete NOID comment (thanks to Denis Excoffier).
4164 Update several URLs and comments in the web pages.
4166 Spelling fixes (thanks to Kevin Lyda and Jonathan Leffler).
4168 Update URL for CLDR Zone->Tzid table (thanks to Yoshito Umaoka).
4171 Release 2013c - 2013-04-19 16:17:40 -0700
4173 Changes affecting current and future timestamps:
4175 Palestine observed DST starting March 29, 2013. (Thanks to
4176 Steffen Thorsen.) From 2013 on, Gaza and Hebron both observe DST,
4177 with the predicted rules being the last Thursday in March at 24:00
4178 to the first Friday on or after September 21 at 01:00.
4180 Assume that the recent change to Paraguay's DST rules is permanent,
4181 by moving the end of DST to the 4th Sunday in March every year.
4182 (Thanks to Carlos Raúl Perasso.)
4184 Changes affecting past timestamps:
4186 Fix some historical data for Palestine to agree with that of
4187 timeanddate.com, as follows:
4189 The spring 2008 change in Gaza and Hebron was on 00:00 Mar 28, not
4192 The fall 2009 change in Gaza and Hebron on Sep 4 was at 01:00, not
4195 The spring 2010 change in Hebron was 00:00 Mar 26, not 00:01 Mar 27.
4197 The spring 2011 change in Gaza was 00:01 Apr 1, not 12:01 Apr 2.
4199 The spring 2011 change in Hebron on Apr 1 was at 00:01, not 12:01.
4201 The fall 2011 change in Hebron on Sep 30 was at 00:00, not 03:00.
4203 Fix times of habitation for Macquarie to agree with the Tasmania
4204 Parks & Wildlife Service history, which indicates that permanent
4205 habitation was 1899-1919 and 1948 on.
4207 Changing affecting metadata only:
4209 Macquarie Island is politically part of Australia, not Antarctica.
4210 (Thanks to Tobias Conradi.)
4212 Sort Macquarie more consistently with other parts of Australia.
4213 (Thanks to Tim Parenti.)
4216 Release 2013b - 2013-03-10 22:33:40 -0700
4218 Changes affecting current and future timestamps:
4220 Haiti uses US daylight-saving rules this year, and presumably future years.
4221 This changes timestamps starting today. (Thanks to Steffen Thorsen.)
4223 Paraguay will end DST on March 24 this year.
4224 (Thanks to Steffen Thorsen.) For now, assume it's just this year.
4226 Morocco does not observe DST during Ramadan;
4227 try to predict Ramadan in Morocco as best we can.
4228 (Thanks to Erik Homoet for the heads-up.)
4230 Changes affecting commentary:
4232 Update URLs in tz-link page. Add URLs for webOS, BB10, iOS.
4233 Update URL for Solaris. Mention Internet RFC 6557.
4234 Update Internet RFCs 2445->5545, 2822->5322.
4235 Switch from FTP to HTTP for Internet RFCs.
4238 Release 2013a - 2013-02-27 09:20:35 -0800
4240 Change affecting binary data format:
4242 The zone offset at the end of version-2-format zone files is now
4243 allowed to be 24:00, as per POSIX.1-2008. (Thanks to Arthur David Olson.)
4245 Changes affecting current and future timestamps:
4247 Chile's 2013 rules, and we guess rules for 2014 and later, will be
4248 the same as 2012, namely Apr Sun>=23 03:00 UTC to Sep Sun>=2 04:00 UTC.
4249 (Thanks to Steffen Thorsen and Robert Elz.)
4251 New Zones Asia/Khandyga, Asia/Ust-Nera, Europe/Busingen.
4252 (Thanks to Tobias Conradi and Arthur David Olson.)
4254 Many changes affect historical timestamps before 1940.
4255 These were deduced from: Milne J. Civil time. Geogr J. 1899
4256 Feb;13(2):173-94 <https://www.jstor.org/stable/1774359>.
4258 Changes affecting the code:
4260 Fix zic bug that mishandled Egypt's 2010 changes (this also affected
4261 the data). (Thanks to Arthur David Olson.)
4263 Fix localtime bug when time_t is unsigned and data files were generated
4264 by a signed time_t system. (Thanks to Doug Bailey for reporting and
4265 to Arthur David Olson for fixing.)
4267 Allow the email address for bug reports to be set by the packager.
4268 The default is tz@iana.org, as before. (Thanks to Joseph S. Myers.)
4270 Update HTML checking to be compatible with Ubuntu 12.10.
4272 Check that files are a safe subset of ASCII. At some point we may
4273 relax this requirement to a safe subset of UTF-8. Without the
4274 check, some non-UTF-8 encodings were leaking into the distribution.
4278 Restore a comment about copyright notices that was inadvertently deleted.
4279 (Thanks to Arthur David Olson.)
4281 Improve the commentary about which districts observe what times
4282 in Russia. (Thanks to Oscar van Vlijmen and Arthur David Olson.)
4284 Add web page links to tz.js.
4286 Add "Run by the Monkeys" to tz-art. (Thanks to Arthur David Olson.)
4289 Release 2012j - 2012-11-12 18:34:49 -0800
4291 Libya moved to CET this weekend, but with DST planned next year.
4292 (Thanks to Even Scharning, Steffen Thorsen, and Tim Parenti.)
4294 Signatures now have the extension .asc, not .sign, as that's more
4295 standard. (Thanks to Phil Pennock.)
4297 The output of 'zdump --version', and of 'zic --version', now
4298 uses a format that is more typical for --version.
4299 (Thanks to Joseph S. Myers.)
4301 The output of 'tzselect --help', 'zdump --help', and 'zic --help'
4302 now uses tz@iana.org rather than the old elsie address.
4304 zic -v now complains about abbreviations that are less than 3
4305 or more than 6 characters, as per Posix. Formerly, it checked
4306 for abbreviations that were more than 3.
4308 'make public' no longer puts its temporary directory under /tmp,
4309 and uses the just-built zic rather than the system zic.
4311 Various fixes to documentation and commentary.
4314 Release 2012i - 2012-11-03 12:57:09 -0700
4316 Cuba switches from DST tomorrow at 01:00. (Thanks to Steffen Thorsen.)
4318 Linker flags can now be specified via LDFLAGS.
4319 AWK now defaults to 'awk', not 'nawk'.
4320 The shell in tzselect now defaults to /bin/bash, but this can
4321 be overridden by specifying KSHELL.
4322 The main web page now mentions the unofficial GitHub repository.
4323 (Thanks to Mike Frysinger.)
4325 Tarball signatures can now be built by running 'make signatures'.
4326 There are also new makefile rules 'tarballs', 'check_public', and
4327 separate makefile rules for each tarball and signature file.
4328 A few makefile rules are now more portable to strict POSIX.
4330 The main web page now lists the canonical IANA URL.
4333 Release 2012h - 2012-10-26 22:49:10 -0700
4335 Bahia no longer has DST. (Thanks to Kelley Cook.)
4337 Tocantins has DST. (Thanks to Rodrigo Severo.)
4339 Israel has new DST rules next year. (Thanks to Ephraim Silverberg.)
4341 Jordan stays on DST this winter. (Thanks to Steffen Thorsen.)
4345 More C modernization, except that at Arthur David Olson's suggestion
4346 the instances of 'register' were kept.
4349 Release 2012g - 2012-10-17 20:59:45 -0700
4351 Samoa fall 2012 and later. (Thanks to Nicholas Pereira and Robert Elz.)
4353 Palestine fall 2012. (Thanks to Steffen Thorsen.)
4357 To attack the version-number problem, this release ships the file
4358 'Makefile' (which contains the release number) in both the tzcode and
4359 the tzdata tarballs. The two Makefiles are identical, and should be
4360 identical in any matching pair of tarballs, so it shouldn't matter
4361 which order you extract the tarballs. Perhaps we can come up with a
4362 better version-number scheme at some point; this scheme does have the
4363 virtue of not adding more files.
4366 Release 2012f - 2012-09-12 23:17:03 -0700
4368 * australasia (Pacific/Fiji): Fiji DST is October 21 through January
4369 20 this year. (Thanks to Steffen Thorsen.)
4372 Release 2012e - 2012-08-02 20:44:55 -0700
4374 * australasia (Pacific/Fakaofo): Tokelau is UT +13, not +14.
4375 (Thanks to Steffen Thorsen.)
4377 * Use a single version number for both code and data.
4379 * .gitignore: New file.
4381 * Remove trailing white space.
4384 Release code2012c-data2012d - 2012-07-19 16:35:33 -0700
4386 Changes for Morocco's timestamps, which take effect in a couple of
4387 hours, along with infrastructure changes to accommodate how the tz
4388 code and data are released on IANA.
4391 Release data2012c - 2012-03-27 12:17:25 -0400
4394 Summer time changes for Morocco (to start late April 2012)
4397 Changes for 2012 for Gaza & the West Bank (Hebron) and Syria
4400 Haiti following US/Canada rules for 2012 (and we're assuming,
4401 for now anyway, for the future).
4404 Release 2012b - 2012-03-02 12:29:15 +0700
4406 There is just one change to tzcode2012b (compared with 2012a):
4407 the Makefile that was accidentally included with 2012a has been
4408 replaced with the version that should have been there, which is
4409 identical with the previous version (from tzcode2011i).
4411 There are just two changes in tzdata2012b compared with 2012a.
4413 Most significantly, summer time in Cuba has been delayed 3 weeks
4414 (now starts April 1 rather than March 11). Since Mar 11 (the old start
4415 date, as listed in 2012a) is just a little over a week away, this
4418 Less importantly, an excess tab in one of the changes in zone.tab
4419 in 2012a has been removed.
4422 Release 2012a - 2012-03-01 18:28:10 +0700
4424 The changes in tzcode2012a (compared to the previous version, 2011i)
4425 are entirely to the README and tz-art.htm and tz-link.htm files, if
4426 none of those concern you, you can ignore the code update. The changes
4427 reflect the changed addresses for the mailing list and the code and
4428 data distribution points & methods (and a link to DateTime::TimeZone::Tzfile
4429 has been added to tz-link.htm).
4431 In tzdata2012a (compared to the previous release, which was 2011n)
4432 the major changes are:
4433 Chile 2011/2012 and 2012/2013 summer time date adjustments.
4434 Falkland Islands onto permanent summer time (we're assuming for the
4435 foreseeable future, though 2012 is all we're fairly certain of.)
4436 Armenia has abolished Summer Time.
4437 Tokelau jumped the International Date Line back last December
4438 (just the same as their near neighbour, Samoa).
4439 America/Creston is a new zone for a small area of British Columbia
4440 There will be a leapsecond 2012-06-30 23:59:60 UTC.
4442 Other minor changes are:
4443 Corrections to 1918 Canadian summer time end dates.
4444 Updated URL for UK time zone history (in comments)
4445 A few typos in Le Corre's list of free French place names (comments)
4448 Release data2011n - 2011-10-30 14:57:54 +0700
4450 There are three changes of note - most urgently, Cuba (America/Havana)
4451 has extended summer time by two weeks, now to end on Nov 13, rather than
4452 the (already past) Oct 30. Second, the Pridnestrovian Moldavian Republic
4453 (Europe/Tiraspol) decided not to split from the rest of Moldova after
4454 all, and consequently that zone has been removed (again) and reinstated
4455 in the "backward" file as a link to Europe/Chisinau. And third, the
4456 end date for Fiji's summer time this summer was moved forward from the
4457 earlier planned Feb 26, to Jan 22.
4459 Apart from that, Moldova (MD) returns to a single entry in zone.tab
4460 (and the incorrect syntax that was in the 2011m version of that file
4461 is so fixed - it would have been fixed in a different way had this
4462 change not happened - that's the "missing" sccs version id).
4465 Release data2011m - 2011-10-24 21:42:16 +0700
4467 In particular, the typos in comments in the data (2011-11-17 should have
4468 been 2011-10-17 as Alan Barrett noted, and spelling of Tiraspol that
4469 Tim Parenti noted) have been fixed, and the change for Ukraine has been
4470 made in all 4 Ukrainian zones, rather than just Kiev (again, thanks to
4471 Tim Parenti, and also Denys Gavrysh)
4473 In addition, I added Europe/Tiraspol to zone.tab.
4475 This time, all the files have new version numbers... (including the files
4476 otherwise unchanged in 2011m that were changed in 2011l but didn't get new
4477 version numbers there...)
4480 Release data2011l - 2011-10-10 11:15:43 +0700
4482 There are just 2 changes that cause different generated tzdata files from
4483 zic, to Asia/Hebron and Pacific/Fiji - the possible change for Bahia, Brazil
4484 is included, but commented out. Compared with the diff I sent out last week,
4485 this version also includes attributions for the sources for the changes
4486 (in much the same format as ado used, but the html tags have not been
4487 checked, verified, or used in any way at all, so if there are errors there,
4488 please let me know.)
4491 Release data2011k - 2011-09-20 17:54:03 -0400
4496 Release data2011j - 2011-09-12 09:22:49 -0400
4498 (contemporary changes for Samoa; past changes for Kenya, Uganda, and
4499 Tanzania); there are also two spelling corrections to comments in
4500 the australasia file (with thanks to Christos Zoulas).
4503 Release 2011i - 2011-08-29 05:56:32 -0400
4508 Release data2011h - 2011-06-15 18:41:48 -0400
4510 Russia and Curaçao changes
4513 Release 2011g - 2011-04-25 09:07:22 -0400
4515 update the rules for Egypt to reflect its abandonment of DST this year
4518 Release 2011f - 2011-04-06 17:14:53 -0400
4523 Release 2011e - 2011-03-31 16:04:38 -0400
4525 Morocco, Chile, and tz-link changes
4528 Release 2011d - 2011-03-14 09:18:01 -0400
4530 changes that impact present-day timestamps in Cuba, Samoa, and Turkey
4533 Release 2011c - 2011-03-07 09:30:09 -0500
4535 These do affect current timestamps in Chile and Annette Island, Canada.
4538 Release 2011b - 2011-02-07 08:44:50 -0500
4543 Release 2011a - 2011-01-24 10:30:16 -0500
4548 Release data2010o - 2010-11-01 09:18:23 -0400
4550 change to the end of DST in Fiji in 2011
4553 Release 2010n - 2010-10-25 08:19:17 -0400
4558 Release 2010m - 2010-09-27 09:24:48 -0400
4560 Hong Kong, Vostok, and zic.c changes
4563 Release 2010l - 2010-08-16 06:57:25 -0400
4568 Release 2010k - 2010-07-26 10:42:27 -0400
4573 Release 2010j - 2010-05-10 09:07:48 -0400
4575 changes for Bahía de Banderas and for version naming
4578 Release data2010i - 2010-04-16 18:50:45 -0400
4580 the end of DST in Morocco on 2010-08-08
4583 Release data2010h - 2010-04-05 09:58:56 -0400
4588 Release data2010g - 2010-03-24 11:14:53 -0400
4593 Release 2010f - 2010-03-22 09:45:46 -0400
4598 Release data2010e - 2010-03-08 14:24:27 -0500
4600 corrects the Dhaka bug found by Danvin Ruangchan
4603 Release data2010d - 2010-03-06 07:26:01 -0500
4608 Release 2010c - 2010-03-01 09:20:58 -0500
4610 changes including KRE's suggestion for earlier initialization of
4611 "goahead" and "goback" structure elements
4614 Release code2010a - 2010-02-16 10:40:04 -0500
4619 Release data2010b - 2010-01-20 12:37:01 -0500
4624 Release data2010a - 2010-01-18 08:30:04 -0500
4629 Release data2009u - 2009-12-26 08:32:28 -0500
4631 changes to DST in Bangladesh
4634 Release 2009t - 2009-12-21 13:24:27 -0500
4639 Release data2009s - 2009-11-14 10:26:32 -0500
4641 (cosmetic) Antarctica change and the DST-in-Fiji-in-2009-and-2010 change
4644 Release 2009r - 2009-11-09 10:10:31 -0500
4646 "antarctica" and "tz-link.htm" changes
4649 Release 2009q - 2009-11-02 09:12:40 -0500
4651 with two corrections as reported by Eric Muller and Philip Newton
4654 Release data2009p - 2009-10-23 15:05:27 -0400
4656 Argentina (including San Luis) changes (with the correction from
4660 Release data2009o - 2009-10-14 16:49:38 -0400
4662 Samoa (commentary only), Pakistan, and Bangladesh changes
4665 Release data2009n - 2009-09-22 15:13:38 -0400
4667 added commentary for Argentina and a change to the end of DST in
4671 Release data2009m - 2009-09-03 10:23:43 -0400
4673 Samoa and Palestine changes
4676 Release data2009l - 2009-08-14 09:13:07 -0400
4678 Samoa (comments only) and Egypt
4681 Release 2009k - 2009-07-20 09:46:08 -0400
4686 Release data2009j - 2009-06-15 06:43:59 -0400
4688 Bangladesh change (with a short turnaround since the DST change is
4692 Release 2009i - 2009-06-08 09:21:22 -0400
4694 updating for DST in Bangladesh this year
4697 Release 2009h - 2009-05-26 09:19:14 -0400
4702 Release data2009g - 2009-04-20 16:34:07 -0400
4707 Release data2009f - 2009-04-10 11:00:52 -0400
4709 correct DST in Pakistan
4712 Release 2009e - 2009-04-06 09:08:11 -0400
4717 Release 2009d - 2009-03-23 09:38:12 -0400
4719 Morocco, Tunisia, Argentina, and American Astronomical Society changes
4722 Release data2009c - 2009-03-16 09:47:51 -0400
4724 change to the start of Cuban DST
4727 Release 2009b - 2009-02-09 11:15:22 -0500
4732 Release 2009a - 2009-01-21 10:09:39 -0500
4737 Release data2008i - 2008-10-21 12:10:25 -0400
4739 southamerica and zone.tab files, with Argentina DST rule changes and
4740 United States zone reordering and recommenting
4743 Release 2008h - 2008-10-13 07:33:56 -0400
4748 Release 2008g - 2008-10-06 09:03:18 -0400
4750 Fix a broken HTML anchor and update Brazil's DST transitions;
4751 there's also a slight reordering of information in tz-art.htm.
4754 Release data2008f - 2008-09-09 22:33:26 -0400
4759 Release 2008e - 2008-07-28 14:11:17 -0400
4761 changes by Arthur David Olson and Jesper Nørgaard Welen
4764 Release data2008d - 2008-07-07 09:51:38 -0400
4766 changes by Arthur David Olson, Paul Eggert, and Rodrigo Severo
4769 Release data2008c - 2008-05-19 17:48:03 -0400
4771 Pakistan, Morocco, and Mongolia
4774 Release data2008b - 2008-03-24 08:30:59 -0400
4776 including renaming Asia/Calcutta to Asia/Kolkata, with a backward
4780 Release 2008a - 2008-03-08 05:42:16 -0500
4785 Release 2007k - 2007-12-31 10:25:22 -0500
4787 most importantly, changes to the "southamerica" file based on
4788 Argentina's readoption of daylight saving time
4791 Release 2007j - 2007-12-03 09:51:01 -0500
4793 1. eliminate the "P" (parameter) macro;
4795 2. the "noncontroversial" changes circulated on the time zone
4796 mailing list (less the changes to "logwtmp.c");
4798 3. eliminate "too many transition" errors when "min" is used in time
4801 4. changes by Paul Eggert (including updated information for Venezuela).
4804 Release data2007i - 2007-10-30 10:28:11 -0400
4806 changes for Cuba and Syria
4809 Release 2007h - 2007-10-01 10:05:51 -0400
4811 changes by Paul Eggert, as well as an updated link to the ICU
4812 project in tz-link.htm
4815 Release 2007g - 2007-08-20 10:47:59 -0400
4817 changes by Paul Eggert
4819 The "leapseconds" file has been updated to incorporate the most
4820 recent International Earth Rotation and Reference Systems Service
4823 There's an addition to tz-art.htm regarding the television show "Medium".
4826 Release 2007f - 2007-05-07 10:46:46 -0400
4828 changes by Paul Eggert (including Haiti, Turks and Caicos, and New
4831 changes to zic.c to allow hour values greater than 24 (along with
4832 Paul's improved time value overflow checking)
4835 Release 2007e - 2007-04-02 10:11:52 -0400
4837 Syria and Honduras changes by Paul Eggert
4839 zic.c variable renaming changes by Arthur David Olson
4842 Release 2007d - 2007-03-20 08:48:30 -0400
4844 changes by Paul Eggert
4846 the elimination of white space at the ends of lines
4849 Release 2007c - 2007-02-26 09:09:37 -0500
4851 changes by Paul Eggert
4854 Release 2007b - 2007-02-12 09:34:20 -0500
4856 Paul Eggert's proposed change to the quotation handling logic in zic.c.
4858 changes to the commentary in "leapseconds" reflecting the IERS
4859 announcement that there is to be no positive leap second at the end
4863 Release 2007a - 2007-01-08 12:28:29 -0500
4865 changes by Paul Eggert
4867 Derick Rethans's Asmara change
4869 Oscar van Vlijmen's Easter Island local mean time change
4871 symbolic link changes
4874 Release 2006p - 2006-11-27 08:54:27 -0500
4876 changes by Paul Eggert
4879 Release 2006o - 2006-11-06 09:18:07 -0500
4881 changes by Paul Eggert
4884 Release 2006n - 2006-10-10 11:32:06 -0400
4886 changes by Paul Eggert
4889 Release 2006m - 2006-10-02 15:32:35 -0400
4891 changes for Uruguay, Palestine, and Egypt by Paul Eggert
4893 (minimalist) changes to zic.8 to clarify "until" information
4896 Release data2006l - 2006-09-18 12:58:11 -0400
4898 Paul's best-effort work on this coming weekend's Egypt time change
4901 Release 2006k - 2006-08-28 12:19:09 -0400
4903 changes by Paul Eggert
4906 Release 2006j - 2006-08-21 09:56:32 -0400
4908 changes by Paul Eggert
4911 Release code2006i - 2006-08-07 12:30:55 -0400
4915 Ken Pizzini's conversion script
4918 Release code2006h - 2006-07-24 09:19:37 -0400
4920 adds public domain notices to four files
4922 includes a fix for transition times being off by a second
4924 adds a new recording to the "arts" file (information courtesy Colin Bowern)
4927 Release 2006g - 2006-05-08 17:18:09 -0400
4929 northamerica changes by Paul Eggert
4932 Release 2006f - 2006-05-01 11:46:00 -0400
4934 a missing version number problem is fixed (with thanks to Bradley
4935 White for catching the problem)
4938 Release 2006d - 2006-04-17 14:33:43 -0400
4940 changes by Paul Eggert
4942 added new items to tz-arts.htm that were found by Paul
4945 Release 2006c - 2006-04-03 10:09:32 -0400
4947 two sets of data changes by Paul Eggert
4949 a fencepost error fix in zic.c
4951 changes to zic.c and the "europe" file to minimize differences
4952 between output produced by the old 32-bit zic and the new 64-bit
4956 Release 2006b - 2006-02-20 10:08:18 -0500
4957 [tz32code2006b + tz64code2006b + tzdata2006b]
4961 All SCCS IDs were bumped to "8.1" for this release.
4964 Release 2006a - 2006-01-30 08:59:31 -0500
4966 changes by Paul Eggert (in particular, Indiana time zone moves)
4968 an addition to the zic manual page to describe how special-case
4969 transitions are handled
4972 Release 2005r - 2005-12-27 09:27:13 -0500
4974 Canadian changes by Paul Eggert
4976 They also add "<pre>" directives to time zone data files and reflect
4977 changes to warning message logic in "zdump.c" (but with calls to
4978 "gettext" kept unbundled at the suggestion of Ken Pizzini).
4981 Release 2005q - 2005-12-13 09:17:09 -0500
4983 Nothing earth-shaking here:
4984 1. Electronic mail addresses have been removed.
4985 2. Casts of the return value of exit have been removed.
4986 3. Casts of the argument of is.* macros have been added.
4987 4. Indentation in one section of zic.c has been fixed.
4988 5. References to dead URLs in the data files have been dealt with.
4991 Release 2005p - 2005-12-05 10:30:53 -0500
4993 "systemv", "tz-link.htm", and "zdump.c" changes
4994 (less the casts of arguments to the is* macros)
4997 Release 2005o - 2005-11-28 10:55:26 -0500
4999 Georgia, Cuba, Nicaragua, and Jordan changes by Paul Eggert
5001 zdump.c lint fixes by Arthur David Olson
5004 Release 2005n - 2005-10-03 09:44:09 -0400
5006 changes by Paul Eggert (both the Uruguay changes and the Kyrgyzstan
5010 Release 2005m - 2005-08-29 12:15:40 -0400
5012 changes by Paul Eggert (with a small tweak to the tz-art change)
5014 a declaration of an unused variable has been removed from zdump.c
5017 Release 2005l - 2005-08-22 12:06:39 -0400
5019 changes by Paul Eggert
5021 overflow/underflow checks by Arthur David Olson, minus changes to
5022 the "Theory" file about the pending addition of 64-bit data (I grow
5023 less confident of the changes being accepted with each passing day,
5024 and the changes no longer increase the data files nine-fold--there's
5025 less than a doubling in size by my local Sun's reckoning)
5028 Release 2005k - 2005-07-14 14:14:24 -0400
5030 The "leapseconds" file has been edited to reflect the recently
5031 announced leap second at the end of 2005.
5033 I've also deleted electronic mail addresses from the files as an
5037 Release 2005j - 2005-06-13 14:34:13 -0400
5039 These reflect changes to limit the length of time zone abbreviations
5040 and the characters used in those abbreviations.
5042 There are also changes to handle POSIX-style "quoted" timezone
5043 environment variables.
5045 The changes were circulated on the time zone mailing list; the only
5046 change since then was the removal of a couple of minimum-length of
5047 abbreviation checks.
5050 Release data2005i - 2005-04-21 15:04:16 -0400
5052 changes (most importantly to Nicaragua and Haiti) by Paul Eggert
5055 Release 2005h - 2005-04-04 11:24:47 -0400
5057 changes by Paul Eggert
5059 minor changes to Makefile and zdump.c to produce more useful output
5060 when doing a "make typecheck"
5063 Release 2005g - 2005-03-14 10:11:21 -0500
5065 changes by Paul Eggert (a change to current DST rules in Uruguay and
5066 an update to a link to time zone software)
5069 Release 2005f - 2005-03-01 08:45:32 -0500
5071 data and documentation changes by Paul Eggert
5074 Release 2005e - 2005-02-10 15:59:44 -0500
5079 Release code2005d - 2005-01-31 09:21:47 -0500
5081 make zic complain about links to links if the -v flag is used
5083 have "make public" do more code checking
5085 add an include to "localtime.c" for the benefit of gcc systems
5088 Release 2005c - 2005-01-17 18:36:29 -0500
5090 get better results when mktime runs on a system where time_t is double
5092 changes to the data files (most importantly to Paraguay)
5095 Release 2005b - 2005-01-10 09:19:54 -0500
5097 Get localtime and gmtime working on systems with exotic time_t types.
5099 Update the leap second commentary in the "leapseconds" file.
5102 Release 2005a - 2005-01-01 13:13:44 -0500
5107 Release code2004i - 2004-12-14 13:42:58 -0500
5109 Deal with systems where time_t is unsigned.
5112 Release code2004h - 2004-12-07 11:40:18 -0500
5114 64-bit-time_t changes
5117 Release 2004g - 2004-11-02 09:06:01 -0500
5119 update to Cuba (taking effect this weekend)
5121 other changes by Paul Eggert
5123 correction of the spelling of Oslo
5125 changed versions of difftime.c and private.h
5128 Release code2004f - 2004-10-21 10:25:22 -0400
5130 Cope with wide-ranging tm_year values.
5133 Release 2004e - 2004-10-11 14:47:21 -0400
5135 Brazil/Argentina/Israel changes by Paul Eggert
5137 changes to tz-link.htm by Paul
5139 one small fix to Makefile
5142 Release 2004d - 2004-09-22 08:27:29 -0400
5144 Avoid overflow problems when TM_YEAR_BASE is added to an integer.
5147 Release 2004c - 2004-08-11 12:06:26 -0400
5149 asctime-related changes
5151 (variants of) some of the documentation changes suggested by Paul Eggert
5154 Release 2004b - 2004-07-19 14:33:35 -0400
5156 data changes by Paul Eggert - most importantly, updates for Argentina
5159 Release 2004a - 2004-05-27 12:00:47 -0400
5161 changes by Paul Eggert
5163 Handle DST transitions that occur at the end of a month in some
5164 years but at the start of the following month in other years.
5166 Add a copy of the correspondence that's the basis for claims about
5167 DST in the Navajo Nation.
5170 Release 2003e - 2003-12-15 09:36:47 -0500
5172 changes by Arthur David Olson (primarily code changes)
5174 changes by Paul Eggert (primarily data changes)
5176 minor changes to "Makefile" and "northamerica" (in the latter case,
5177 optimization of the "Toronto" rules)
5180 Release 2003d - 2003-10-06 09:34:44 -0400
5182 changes by Paul Eggert
5185 Release 2003c - 2003-09-16 10:47:05 -0400
5187 Fix bad returns in zic.c's inleap function.
5188 Thanks to Bradley White for catching the problem!
5191 Release 2003b - 2003-09-16 07:13:44 -0400
5193 Add a "--version" option (and documentation) to the zic and zdump commands.
5195 changes to overflow/underflow checking in zic
5197 a localtime typo fix.
5199 Update the leapseconds and tz-art.htm files.
5202 Release 2003a - 2003-03-24 09:30:54 -0500
5204 changes by Paul Eggert
5206 a few additions and modifications to the tz-art.htm file
5209 Release 2002d - 2002-10-15 13:12:42 -0400
5211 changes by Paul Eggert, less the "Britain (UK)" change in iso3166.tab
5213 There's also a new time zone quote in "tz-art.htm".
5216 Release 2002c - 2002-04-04 11:55:20 -0500
5218 changes by Paul Eggert
5220 Change zic.c to avoid creating symlinks to files that don't exist.
5223 Release 2002b - 2002-01-28 12:56:03 -0500
5225 [These change notes are for Release 2002a, which was corrupted.
5226 2002b was a corrected version of 2002a.]
5228 changes by Paul Eggert
5230 Update the "leapseconds" file to note that there'll be no leap
5231 second at the end of June, 2002.
5233 Change "zic.c" to deal with a problem in handling the "Asia/Bishkek" zone.
5235 Change to "difftime.c" to avoid sizeof problems.
5238 Release 2001d - 2001-10-09 13:31:32 -0400
5240 changes by Paul Eggert
5243 Release 2001c - 2001-06-05 13:59:55 -0400
5245 changes by Paul Eggert and Andrew Brown
5248 Release 2001b - 2001-04-05 16:44:38 -0400
5250 changes by Paul Eggert (modulo jnorgard's typo fix)
5252 tz-art.htm has been HTMLified.
5255 Release 2001a - 2001-03-13 12:57:44 -0500
5257 changes by Paul Eggert
5259 An addition to the "leapseconds" file: comments with the text of the
5260 latest IERS leap second notice.
5262 Trailing white space has been removed from data file lines, and
5263 repeated spaces in "Rule Jordan" lines in the "asia" file have been
5267 Release 2000h - 2000-12-14 15:33:38 -0500
5269 changes by Paul Eggert
5271 one typo fix in the "art" file
5273 With providence, this is the last update of the millennium.
5276 Release 2000g - 2000-10-10 11:35:22 -0400
5278 changes by Paul Eggert
5280 correction of John Mackin's name submitted by Robert Elz
5282 Garry Shandling's Daylight Saving Time joke (!?!) from the recent
5283 Emmy Awards broadcast.
5286 Release 2000f - 2000-08-10 09:31:58 -0400
5288 changes by Paul Eggert
5290 Added information in "tz-art.htm" on a Seinfeld reference to DST.
5292 Error checking and messages in the "yearistype" script have been
5296 Release 2000e - 2000-07-31 09:27:54 -0400
5298 data changes by Paul Eggert
5300 a change to the default value of the defined constant HAVE_STRERROR
5302 the addition of a Dave Barry quote on DST to the tz-arts file
5305 Release 2000d - 2000-04-20 15:43:04 -0400
5307 changes to the documentation and code of strftime for C99 conformance
5309 a bug fix for date.c
5311 These are based on (though modified from) changes by Paul Eggert.
5314 Release 2000c - 2000-03-04 10:31:43 -0500
5316 changes by Paul Eggert
5319 Release 2000b - 2000-02-21 12:16:29 -0500
5321 changes by Paul Eggert and Joseph Myers
5323 modest tweaks to the tz-art.htm and tz-link.htm files
5326 Release 2000a - 2000-01-18 09:21:26 -0500
5328 changes by Paul Eggert
5330 The two hypertext documents have also been renamed.
5333 Release code1999i-data1999j - 1999-11-15 18:43:22 -0500
5335 Paul Eggert's changes
5337 additions to the "zic" manual page and the "Arts.htm" file
5340 Release code1999h-data1999i - 1999-11-08 14:55:21 -0500
5345 Release data1999h - 1999-10-07 03:50:29 -0400
5347 changes by Paul Eggert to "europe" (most importantly, fixing
5348 Lithuania and Estonia)
5351 Release 1999g - 1999-09-28 11:06:18 -0400
5353 data changes by Paul Eggert (most importantly, the change for
5354 Lebanon that buys correctness for this coming Sunday)
5356 The "code" file contains changes to "Makefile" and "checktab.awk" to
5357 allow better checking of time zone files before they are published.
5360 Release 1999f - 1999-09-23 09:48:14 -0400
5362 changes by Arthur David Olson and Paul Eggert
5365 Release 1999e - 1999-08-17 15:20:54 -0400
5367 changes circulated by Paul Eggert, although the change to handling
5368 of DST-specifying timezone names has been commented out for now
5369 (search for "XXX" in "localtime.c" for details). These files also
5370 do not make any changes to the start of DST in Brazil.
5372 In addition to Paul's changes, there are updates to "Arts.htm" and
5376 Release 1999d - 1999-03-30 11:31:07 -0500
5378 changes by Paul Eggert
5380 The Makefile's "make public" rule has also been changed to do a test
5381 compile of each individual time zone data file (which should help
5382 avoid problems such as the one we had with Nicosia).
5385 Release 1999c - 1999-03-25 09:47:47 -0500
5387 changes by Paul Eggert, most importantly the change for Chile.
5390 Release 1999b - 1999-02-01 17:51:44 -0500
5392 changes by Paul Eggert
5394 code changes (suggested by Mani Varadarajan, mani at be.com) for
5395 correct handling of symbolic links when building using a relative directory
5397 code changes to generate correct messages for failed links
5399 updates to the URLs in Arts.htm
5402 Release 1999a - 1999-01-19 16:20:29 -0500
5404 error message internationalizations and corrections in zic.c and
5405 zdump.c (as suggested by Vladimir Michl, vladimir.michl at upol.cz,
5409 Release code1998h-data1998i - 1998-10-01 09:56:10 -0400
5411 changes for Brazil, Chile, and Germany
5413 support for use of "24:00" in the input files for the time zone compiler
5416 Release code1998g-data1998h - 1998-09-24 10:50:28 -0400
5418 changes by Paul Eggert
5420 correction to a define in the "private.h" file
5423 Release data1998g - 1998-08-11 03:28:35 -0000
5424 [tzdata1998g.tar.gz is missing!]
5426 Lithuanian change provided by mgedmin at pub.osf.it
5428 Move creation of the GMT link with Etc/GMT to "etcetera" (from
5429 "backward") to ensure that the GMT file is created even where folks
5430 don't want the "backward" links (as suggested by Paul Eggert).
5433 Release data1998f - 1998-07-20 13:50:00 -0000
5434 [tzdata1998f.tar.gz is missing!]
5436 Update the "leapseconds" file to include the newly announced
5437 insertion at the end of 1998.
5440 Release code1998f - 1998-06-01 10:18:31 -0400
5442 addition to localtime.c by Guy Harris
5445 Release 1998e - 1998-05-28 09:56:26 -0400
5447 The Makefile is changed to produce zoneinfo-posix rather than
5448 zoneinfo/posix, and to produce zoneinfo-leaps rather than
5451 data changes by Paul Eggert
5453 changes from Guy Harris to provide asctime_r and ctime_r
5455 A usno1998 file (substantially identical to usno1997) has been added.
5458 Release 1998d - 1998-05-14 11:58:34 -0400
5460 changes to comments (in particular, elimination of references to CIA maps).
5461 "Arts.htm", "WWW.htm", "asia", and "australasia" are the only places
5462 where changes occur.
5465 Release 1998c - 1998-02-28 12:32:26 -0500
5467 changes by Paul Eggert (save the "French correction," on which I'll
5468 wait for the dust to settle)
5472 changes and additions to Arts.htm
5475 Release 1998b - 1998-01-17 14:31:51 -0500
5477 URL cleanups and additions
5480 Release 1998a - 1998-01-13 12:37:35 -0500
5482 changes by Paul Eggert
5485 Release code1997i-data1997k - 1997-12-29 09:53:41 -0500
5487 changes by Paul Eggert, with minor modifications from Arthur David
5488 Olson to make the files more browser friendly
5491 Release code1997h-data1997j - 1997-12-18 17:47:35 -0500
5493 minor changes to put "TZif" at the start of each timezone information file
5495 a rule has also been added to the Makefile so you can
5497 to just recompile the zone information files (rather than doing a
5498 full "make install" with its other effects).
5501 Release data1997i - 1997-10-07 08:45:38 -0400
5503 changes to Africa by Paul Eggert
5506 Release code1997g-data1997h - 1997-09-04 16:56:54 -0400
5508 corrections for Uruguay (and other locations)
5510 Arthur David Olson's simple-minded fix allowing mktime to both
5511 correctly handle leap seconds and correctly handle tm_sec values
5512 upon which arithmetic has been performed.
5515 Release code1997f-data1997g - 1997-07-19 13:15:02 -0400
5517 Paul Eggert's updates
5519 a small change to a function prototype;
5521 "Music" has been renamed "Arts.htm", HTMLified, and augmented to
5522 include information on Around the World in Eighty Days.
5525 Release code1997e-data1997f - 1997-05-03 18:52:34 -0400
5527 fixes to zic's error handling
5529 changes inspired by the item circulated on Slovenia
5531 The description of Web resources has been HTMLified for browsing
5534 A new piece of tz-related music has been added to the "Music" file.
5537 Release code1997d-data1997e - 1997-03-29 12:48:52 -0500
5539 Paul Eggert's latest suggestions
5542 Release code1997c-data1997d - 1997-03-07 20:37:54 -0500
5544 changes to "zic.c" to correct performance of the "-s" option
5546 a new file "usno1997"
5549 Release data1997c - 1997-03-04 09:58:18 -0500
5554 Release 1997b - 1997-02-27 18:34:19 -0500
5556 The data file incorporates the 1997 leap second.
5558 The code file incorporates Arthur David Olson's take on the
5559 zic/multiprocessor/directory-creation situation.
5562 Release 1997a - 1997-01-21 09:11:10 -0500
5564 Paul Eggert's Antarctica (and other changes)
5566 Arthur David Olson finessed the "getopt" issue by checking against
5567 both -1 and EOF (regardless of POSIX, SunOS 4.1.1's manual says -1
5568 is returned while SunOS 5.5's manual says EOF is returned).
5571 Release code1996o-data1996n - 1996-12-27 21:42:05 -0500
5573 Paul Eggert's latest changes
5576 Release code1996n - 1996-12-16 09:42:02 -0500
5578 link snapping fix from Bruce Evans (via Garrett Wollman)
5581 Release data1996m - 1996-11-24 02:37:34 -0000
5582 [tzdata1996m.tar.gz is missing!]
5584 Paul Eggert's batch of changes
5587 Release code1996m-data1996l - 1996-11-05 14:00:12 -0500
5589 No functional changes here; the files have simply been changed to
5590 make more use of ISO style dates in comments. The names of the above
5591 files now include the year in full.
5594 Release code96l - 1996-09-08 17:12:20 -0400
5596 tzcode96k was missing a couple of pieces.
5599 Release 96k - 1996-09-08 16:06:22 -0400
5601 the latest round of changes from Paul Eggert
5603 the recent Year 2000 material
5606 Release code96j - 1996-07-30 13:18:53 -0400
5608 Set sp->typecnt as suggested by Timothy Patrick Murphy.
5611 Release code96i - 1996-07-27 20:11:35 -0400
5613 Paul's suggested patch for strftime %V week numbers
5616 Release data96i - 1996-07-01 18:13:04 -0400
5618 "northamerica" and "europe" changes by Paul Eggert
5621 Release code96h - 1996-06-05 08:02:21 -0400
5623 fix for handling transitions specified in Universal Time
5625 Some "public domain" notices have also been added.
5628 Release code96g - 1996-05-16 14:00:26 -0400
5630 fix for the simultaneous-DST-and-zone-change challenge
5633 Release data96h - 1996-05-09 17:40:51 -0400
5635 changes by Paul Eggert
5638 Release code96f-data96g - 1996-05-03 03:09:59 -0000
5639 [tzcode96f.tar.gz + tzdata96g.tar.gz are both missing!]
5641 The changes get us some of the way to fixing the problems noted in Paul
5642 Eggert's letter yesterday (in addition to a few others). The approach
5643 has been to make zic a bit smarter about figuring out what time zone
5644 abbreviations apply just after the time specified in the "UNTIL" part
5645 of a zone line. Putting the smarts in zic means avoiding having
5646 transition times show up in both "Zone" lines and "Rule" lines, which
5647 in turn avoids multiple transition time entries in time zone files.
5648 (This also makes the zic input files such as "europe" a bit shorter and
5649 should ease maintenance.)
5652 Release data96f - 1996-04-19 19:20:03 -0000
5653 [tzdata96f.tar.gz is missing!]
5655 The only changes are to the "northamerica" file; the time zone
5656 abbreviation for Denver is corrected to MST (and MDT), and the
5657 comments for Mexico have been updated.
5660 Release data96e - 1996-03-19 17:37:26 -0500
5662 Proposals by Paul Eggert, in particular the Portugal change that
5663 comes into play at the end of this month.
5666 Release data96d - 1996-03-18 20:49:39 -0500
5671 Release code96e - 1996-02-29 15:43:27 -0000
5672 [tzcode96e.tar.gz is missing!]
5674 internationalization changes and the fix to the documentation for strftime
5677 Release code96d-data96c - 1996-02-12 11:05:27 -0500
5679 The "code" file simply updates Bob Kridle's electronic address.
5681 The "data" file updates rules for Mexico.
5684 Release data96b - 1996-01-27 15:44:42 -0500
5689 Release code96c - 1996-01-16 16:58:15 -0500
5691 leap-year streamlining and binary-search changes
5696 Release code96b - 1996-01-10 20:42:39 -0500
5698 fixes and enhancements from Paul Eggert, including code that
5699 emulates the behavior of recent versions of the SunOS "date"
5703 Release 96a - 1996-01-06 09:08:24 -0500
5707 fixes to strftime.c for correct ISO 8601 week number generation,
5708 plus support for two new formats ('G' and 'g') to give ISO 8601 year
5709 numbers (which are not necessarily the same as calendar year numbers)
5712 Release code95i-data95m - 1995-12-21 12:46:47 -0500
5714 The latest revisions from Paul Eggert are included, the usno1995
5715 file has been updated, and a new file ("WWW") covering useful URLs
5719 Release code95h-data95l - 1995-12-19 18:10:12 -0500
5721 A simplification of a macro definition, a change to data for Sudan,
5722 and (for last minute shoppers) notes in the "Music" file on the CD
5726 Release code95g-data95k - 1995-10-30 10:32:47 -0500
5728 (slightly reformatted) 8-bit-clean proposed patch
5730 minor patch: US/Eastern -> America/New_York
5732 snapshot of the USNO's latest data ("usno1995")
5734 some other minor cleanups
5737 Release code95f-data95j - 1995-10-28 21:01:34 -0000
5738 [tzcode95f.tar.gz + tzdata95j.tar.gz are both missing!]
5742 support for 64-bit time_t's
5744 optimization in localtime.c
5747 Release code95e - 1995-10-13 13:23:57 -0400
5749 the mktime change to scan from future to past when trying to find time zone
5753 Release data95i - 1995-09-26 10:43:26 -0400
5755 For Canada/Central, guess that the Sun customer's "one week too
5756 early" was just a approximation, and the true error is one month
5757 too early. This is consistent with the rest of Canada.
5760 Release data95h - 1995-09-21 11:26:48 -0400
5762 latest changes from Paul Eggert
5765 Release code95d - 1995-09-14 11:14:45 -0400
5767 the addition of a "Music" file, which documents four recorded
5768 versions of the tune "Save That Time".
5771 Release data95g - 1995-09-01 17:21:36 -0400
5773 "yearistype" correction
5776 Release data95f - 1995-08-28 20:46:56 -0400
5778 Paul Eggert's change to the australasia file
5781 Release data95e - 1995-07-08 18:02:34 -0400
5783 The only change is a leap second at the end of this year.
5784 Thanks to Bradley White for forwarding news on the leap second.
5787 Release data95d - 1995-07-03 13:26:22 -0400
5789 Paul Eggert's changes
5792 Release data95c - 1995-07-02 19:19:28 -0400
5794 changes to "asia", "backward", "europe", and "southamerica"
5795 (read: northamericacentrics need not apply)
5798 Release code95c - 1995-03-13 14:00:46 -0500
5800 one-line fix for sign extension problems in detzcode
5803 Release 95b - 1995-03-04 11:22:38 -0500
5805 Minor changes in both:
5807 The "code" file contains a workaround for the lack of "unistd.h" in
5808 Microsoft C++ version 7.
5810 The "data" file contains a fixed "Link" for America/Shiprock.
5813 Release 94h - 1994-12-10 12:51:14 -0500
5817 * incorporate the changes to "zdump" and "date" to make changes to
5818 the "TZ" environment variable permanent;
5820 * incorporate the table changes by Paul Eggert;
5822 * include (and document) support for universal time specifications in
5823 data files - but do not (yet) include use of this feature in the
5826 Think of this as "TZ Classic" - the software has been set up not to break if
5827 universal time shows up in its input, and data entries have been
5828 left as is so as not to break existing implementations.
5831 Release data94f - 1994-08-20 12:56:09 -0400
5833 (with thanks!) the latest data updates from Paul Eggert
5836 Release data94e - 1994-06-04 13:13:53 -0400
5841 Release code94g - 1994-05-05 12:14:07 -0400
5843 fix missing "optind.c" and a reference to it in the Makefile
5846 Release code94f - 1994-05-05 13:00:33 -0000
5847 [tzcode94f.tar.gz is missing!]
5849 changes to avoid overflow in difftime, as well as changes to cope
5850 with the 52/53 challenge in strftime
5853 Release code94e - 1994-03-30 23:32:59 -0500
5855 change for the benefit of PCTS
5858 Release 94d - 1994-02-24 15:42:25 -0500
5860 Avoid clashes with POSIX semantics for zones such as GMT+4.
5862 Some other very minor housekeeping is also present.
5865 Release code94c - 1994-02-10 08:52:40 -0500
5867 Fix bug where mkdirs was broken unless you compile with
5868 -fwritable-strings (which is generally losing to do).
5871 Release 94b - 1994-02-07 10:04:33 -0500
5873 work by Paul Eggert who notes:
5875 I found another book of time zone histories by E W Whitman; it's not
5876 as extensive as Shanks but has a few goodies of its own. I used it
5877 to update the tables. I also fixed some more as a result of
5878 correspondence with Adam David and Peter Ilieve, and move some stray
5879 links from 'europe' to 'backward'. I corrected some scanning errors
5882 As far as the code goes, I fixed zic to allow years in the range
5883 INT_MIN to INT_MAX; this fixed a few boundary conditions around 1900.
5884 And I cleaned up the zic documentation a little bit.
5887 Release data94a - 1994-02-03 08:58:54 -0500
5889 It simply incorporates the recently announced leap second into the
5893 Release 93g - 1993-11-22 17:28:27 -0500
5895 Paul Eggert has provided a good deal of historic information (based
5896 on Shanks), and there are some code changes to deal with the buglets
5897 that crawled out in dealing with the new information.
5900 Release 93f - 1993-10-15 12:27:46 -0400
5902 Paul Eggert's changes
5905 Release 93e - 1993-09-05 21:21:44 -0400
5907 This has updated data for Israel, England, and Kwajalein. There's
5908 also an update to "zdump" to cope with Kwajalein's 24-hour jump.
5909 Thanks to Paul Eggert and Peter Ilieve for the changes.
5912 Release 93d - 1993-06-17 23:34:17 -0400
5914 new fix and new data on Israel
5917 Release 93c - 1993-06-06 19:31:55 -0400
5922 Release 93b - 1993-02-02 14:53:58 -0500
5924 updated "leapseconds" file
5927 Release 93 - 1993-01-08 07:01:06 -0500
5929 At kre's suggestion, the package has been split in two - a code piece
5930 (which also includes documentation) that's only of use to folks who
5931 want to recompile things and a data piece useful to anyone who can
5934 The new version has a few changes to the data files, a few
5935 portability changes, and an off-by-one fix (with thanks to
5936 Tom Karzes at deshaw.com for providing a description and a
5940 Release 92c - 1992-11-21 17:35:36 -0000
5941 [tz92c.tar.Z is missing!]
5943 The fallout from the latest round of DST transitions.
5945 There are changes for Portugal, Saskatchewan, and "Pacific-New";
5946 there's also a change to "zic.c" that makes it portable to more systems.
5949 Release 92 - 1992-04-25 18:17:03 -0000
5950 [tz92.tar.Z is missing!]
5952 By popular demand (well, at any rate, following a request by kre at munnari)
5955 The 1989 update of the time zone package featured:
5957 * POSIXization (including interpretation of POSIX-style TZ environment
5958 variables, provided by Guy Harris),
5959 * ANSIfication (including versions of "mktime" and "difftime"),
5960 * SVIDulation (an "altzone" variable)
5961 * MACHination (the "gtime" function)
5962 * corrections to some time zone data (including corrections to the rules
5963 for Great Britain and New Zealand)
5964 * reference data from the United States Naval Observatory for folks who
5965 want to do additional time zones
5966 * and the 1989 data for Saudi Arabia.
5968 (Since this code will be treated as "part of the implementation" in some
5969 places and as "part of the application" in others, there's no good way to
5970 name functions, such as timegm, that are not part of the proposed ANSI C
5971 standard; such functions have kept their old, underscore-free names in this
5974 And the "dysize" function has disappeared; it was present to allow
5975 compilation of the "date" command on old BSD systems, and a version of "date"
5976 is now provided in the package. The "date" command is not created when you
5977 "make all" since it may lack options provided by the version distributed with
5978 your operating system, or may not interact with the system in the same way
5979 the native version does.
5981 Since POSIX frowns on correct leap second handling, the default behavior of
5982 the "zic" command (in the absence of a "-L" option) has been changed to omit
5983 leap second information from its output files.
5989 This file contains copies of the part of each release announcement
5990 that talks about the changes in that release. The text has been
5991 adapted and reformatted for the purposes of this file.
5993 Traditionally a release R consists of a pair of tarball files,
5994 tzcodeR.tar.gz and tzdataR.tar.gz. However, some releases (e.g.,
5995 code2010a, data2012c) consist of just one or the other tarball, and a
5996 few (e.g., code2012c-data2012d) have tarballs with mixed version
5997 numbers. Recent releases also come in an experimental format
5998 consisting of a single tarball tzdb-R.tar.lz with extra data.
6000 Release timestamps are taken from the release's commit (for newer,
6001 Git-based releases), from the newest file in the tarball (for older
6002 releases, where this info is available) or from the email announcing
6003 the release (if all else fails; these are marked with a time zone
6004 abbreviation of -0000 and an "is missing!" comment).
6006 Earlier versions of the code and data were not announced on the tz
6007 list and are not summarized here.
6009 This file is in the public domain.