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Extra transition for Europe/London with 2023d
by Derick Rethans Jan. 14, 2024

Jan. 14, 2024

Hi, I have just updated the tzdb for PHP, and one of our tests started failing, and it turned out due to an unexpected data change: Previously, the following transitions existed: … 1994-03-27 01:00:00 UT ( 764730000) = 1 [ 3600 1 4 'BST' (0,0)] 1994-10-23 01:00:00 UT ( 782874000) = 2 [ 0 0 8 'GMT' (0,0)] 1995-03-26 01:00:00 UT ( 796179600) = 1 [ 3600 1 4 'BST' (0,0)] 1995-10-22 01:00:00 UT ( 814323600) = 2 [ 0 0 8 'GMT' (0,0)] 1996-03-31 01:00:00 UT ( 828234000) = 1 [ 3600 1 4 'BST' (0,0)] POSIX string: GMT0BST,M3.5.0/1,M10.5.0 std: 2 [ 0 0 8 'GMT' (0,0)] dst: 1 [ 3600 1 4 'BST' (0,0)] But now, they include an extra one for Jan 1st, 1996, with the March 31st one now not being the last one: … 1994-03-27 01:00:00 UT ( 764730000) = 1 [ 3600 1 4 'BST' (0,0)] 1994-10-23 01:00:00 UT ( 782874000) = 2 [ 0 0 8 'GMT' (0,0)] 1995-03-26 01:00:00 UT ( 796179600) = 1 [ 3600 1 4 'BST' (0,0)] 1995-10-22 01:00:00 UT ( 814323600) = 2 [ 0 0 8 'GMT' (0,0)] 1996-01-01 00:00:00 UT ( 820454400) = 2 [ 0 0 8 'GMT' (0,0)] POSIX string: GMT0BST,M3.5.0/1,M10.5.0 std: 2 [ 0 0 8 'GMT' (0,0)] dst: 1 [ 3600 1 4 'BST' (0,0)] I couldn't find anywhere in tzfile.5 or theory.html whether the last generated transition must match a transition as specified with the POSIX string (as it did with 2023c and earlier), but I vaguely remember having read such a thing when I implemented the POSIX string parsing logic. As far as I know so-far, the only effect it has on PHP users is that they will now see an extra transition when they enumerate them (the 1996-01-01 is inserted). I think I am mostly flagging this up because this was an unexpected change. cheers, Derick -- https://derickrethans.nl | https://xdebug.org | https://dram.io Author of Xdebug. Like it? Consider supporting me: https://xdebug.org/support Host of PHP Internals News: https://phpinternals.news mastodon: @derickr@phpc.social @xdebug@phpc.social twitter: @derickr and @xdebug

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[PROPOSED] "m" now abbreviates both "maximum" and "minimum"
by Paul Eggert Jan. 11, 2024

Jan. 11, 2024

* zishrink.awk: Add comment about "m". --- zishrink.awk | 3 +++ 1 file changed, 3 insertions(+) diff --git a/zishrink.awk b/zishrink.awk index 66968e86..eb4aa785 100644 --- a/zishrink.awk +++ b/zishrink.awk @@ -199,6 +199,9 @@ function process_input_line(line, \ } # Abbreviate "max", "min", "only" and month names. + # Although "max" and "min" can both be abbreviated to just "m", + # use the longer forms "ma" and "mi" for now, + # for compatibility with zic 2023d and earlier. gsub(/ max /, " ma ", line) gsub(/ min /, " mi ", line) gsub(/ only /, " o ", line) -- 2.40.1

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NIST URLs for leap-seconds.list in leapseconds.awk
by PoolMUC＠web.de Jan. 10, 2024

Jan. 10, 2024

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Ontario 1949-1950 DST->STD in Sep not Nov
by Brian Inglis Jan. 10, 2024

Jan. 10, 2024

I noticed changes in the DST->STD transition dates to the follwing week mentioned in an Alexandria, Ontario weekly newspaper article linked from a page on an unrelated issue, and checking that against zdump found that 1949 & 1950 appear to have transitioned in November, rather than September as in other years from 1946-1956, which from comments in northamerica, appear to derive from Shanks & Pottenger. So I also downloaded the same paper's issue from the same week of September in the other questionable year, and found another article announcing the change that weekend. As well as time being the lede in top of front page articles about municipal business, there are also municipal notices of time changes in later pages, as well as Canadian National railway ads announcing updated time tables being available from that weekend, and an article listing updated CNR train times from Montreal, and a mention of a follow up when Montreal time changes the weekend following Ontario cities. The attached files show relevant edited pdftotext extracts from the PDFs. Note that the municipality changed its time a day leter than elsewhere in Ontario, midnight Sunday/Monday rather than Saturday/Sunday, so that people will not miss Sunday church services, but Monday work does not matter! [Canada traditionally calls the prairie provinces the "Bible Belt" and there are visible signs of that, including dry municipalities where alcohol was not available, but that did not stop many bars and shops in nearby towns opening Sundays, if there was enough business to be worth it, whereas many eastern provinces had legal restrictions on stores and bars opening on Sundays until recently.]

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trailing whitespace in IERS leap-seconds.list file
by Paul Eggert Jan. 10, 2024

Jan. 10, 2024

Martin Burnicki writes that the IERS's current leap-seconds.list file has a notice that it's in the public domain. Thanks: this means there's no copyright issue in including a copy of the file in the Time Zone Database (TZDB). While testing that, though, I got the following warning from our version control system: .git/rebase-apply/patch:284: trailing whitespace. # Since the adoption of this system in 1972 it has been necessary to add a number of seconds to UTC, warning: 1 line adds whitespace errors. This warning occurs because line 21 of <https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list> contains a trailing space character. Could you please remove it? That will lessen aggravation downstream. Thanks.

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[PROPOSED] Miquelon 1911 transition was June 15 not May 15
by Paul Eggert Jan. 10, 2024

Jan. 10, 2024

I found a new source: Société Française de Physique, Recueil de constantes physiques (1913), page 752 (errata and addenda), 18b. It agrees with Shanks about the adoption of standard time in French possessions, except for Miquelon. Prefer it to Shanks. Also, fill in day of month (e.g., “Jan 1” not “Jan”) for other transitions, since the source seems careful about the day. * NEWS: Mention this. * africa (Africa/Ndjamena, Africa/Abidjan): * australasia (Pacific/Gambier, Pacific/Marquesas, Pacific/Tahiti) (Pacific/Guadalcanal): * northamerica (America/Martinique): * southamerica (America/Cayenne): Fill in day of month as 1. This does not change the transitions; it’s merely documentation. * northamerica (America/Miquelon): 1911 transition was Jun 15, not May 15. --- NEWS | 2 ++ africa | 8 ++++++-- australasia | 12 ++++++++---- northamerica | 8 ++++++-- southamerica | 5 ++++- 5 files changed, 26 insertions(+), 9 deletions(-) diff --git a/NEWS b/NEWS index 6dba3dfb..f0ccfa87 100644 --- a/NEWS +++ b/NEWS @@ -11,6 +11,8 @@ Unreleased, experimental changes From 1947 through 1949, Toronto's transitions occurred at 02:00 not 00:00. (Thanks to Chris Walton.) + In 1911 Miquelon adopted standard time on June 15, not May 15. + Changes to code The FROM and TO columns of Rule lines can no longer be "minimum" diff --git a/africa b/africa index 6fae18c0..92d823a0 100644 --- a/africa +++ b/africa @@ -30,6 +30,10 @@ # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94. # https://www.jstor.org/stable/1774359 # +# For the 1911/1912 establishment of standard time in French possessions, see: +# Société Française de Physique, Recueil de constantes physiques (1913), +# page 752, 18b. +# # European-style abbreviations are commonly used along the Mediterranean. # For sub-Saharan Africa abbreviations were less standardized. # Previous editions of this database used WAT, CAT, SAT, and EAT @@ -113,7 +117,7 @@ Zone Atlantic/Cape_Verde -1:34:04 - LMT 1912 Jan 01 2:00u # Praia # Chad # Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone Africa/Ndjamena 1:00:12 - LMT 1912 # N'Djamena +Zone Africa/Ndjamena 1:00:12 - LMT 1912 Jan 1 # N'Djamena 1:00 - WAT 1979 Oct 14 1:00 1:00 WAST 1980 Mar 8 1:00 - WAT @@ -139,7 +143,7 @@ Zone Africa/Ndjamena 1:00:12 - LMT 1912 # N'Djamena # Inaccessible, Nightingale: uninhabited # Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone Africa/Abidjan -0:16:08 - LMT 1912 +Zone Africa/Abidjan -0:16:08 - LMT 1912 Jan 1 0:00 - GMT ############################################################################### diff --git a/australasia b/australasia index dc98c1e2..a9e9eb4a 100644 --- a/australasia +++ b/australasia @@ -420,11 +420,11 @@ Zone Pacific/Fiji 11:55:44 - LMT 1915 Oct 26 # Suva # French Polynesia # Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone Pacific/Gambier -8:59:48 - LMT 1912 Oct # Rikitea +Zone Pacific/Gambier -8:59:48 - LMT 1912 Oct 1 # Rikitea -9:00 - -09 -Zone Pacific/Marquesas -9:18:00 - LMT 1912 Oct +Zone Pacific/Marquesas -9:18:00 - LMT 1912 Oct 1 -9:30 - -0930 -Zone Pacific/Tahiti -9:58:16 - LMT 1912 Oct # Papeete +Zone Pacific/Tahiti -9:58:16 - LMT 1912 Oct 1 # Papeete -10:00 - -10 # Clipperton (near North America) is administered from French Polynesia; # it is uninhabited. @@ -802,7 +802,7 @@ Zone Pacific/Apia 12:33:04 - LMT 1892 Jul 5 # Solomon Is # excludes Bougainville, for which see Papua New Guinea # Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone Pacific/Guadalcanal 10:39:48 - LMT 1912 Oct # Honiara +Zone Pacific/Guadalcanal 10:39:48 - LMT 1912 Oct 1 # Honiara 11:00 - +11 # Tokelau @@ -963,6 +963,10 @@ Zone Pacific/Efate 11:13:16 - LMT 1912 Jan 13 # Vila # Milne J. Civil time. Geogr J. 1899 Feb;13(2):173-94. # https://www.jstor.org/stable/1774359 # +# For the 1911/1912 establishment of standard time in French possessions, see: +# Société Française de Physique, Recueil de constantes physiques (1913), +# page 752, 18b. +# # A reliable and entertaining source about time zones is # Derek Howse, Greenwich time and longitude, Philip Wilson Publishers (1997). # diff --git a/northamerica b/northamerica index 44fd50bd..0163d17a 100644 --- a/northamerica +++ b/northamerica @@ -1268,6 +1268,10 @@ Zone America/Menominee -5:50:27 - LMT 1885 Sep 18 12:00 # <http://cs.ucla.edu/~eggert/The-Waste-of-Daylight-19th.pdf> # [PDF] (1914-03) # +# For the 1911/1912 establishment of standard time in French possessions, see: +# Société Française de Physique, Recueil de constantes physiques (1913), +# page 752, 18b. +# # See the 'europe' file for Greenland. # Canada @@ -3437,7 +3441,7 @@ Zone America/Jamaica -5:07:10 - LMT 1890 # Kingston # Martinique # Zone NAME STDOFF RULES FORMAT [UNTIL] Zone America/Martinique -4:04:20 - LMT 1890 # Fort-de-France - -4:04:20 - FFMT 1911 May # Fort-de-France MT + -4:04:20 - FFMT 1911 May 1 # Fort-de-France MT -4:00 - AST 1980 Apr 6 -4:00 1:00 ADT 1980 Sep 28 -4:00 - AST @@ -3544,7 +3548,7 @@ Zone America/Puerto_Rico -4:24:25 - LMT 1899 Mar 28 12:00 # San Juan # St Pierre and Miquelon # There are too many St Pierres elsewhere, so we'll use 'Miquelon'. # Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone America/Miquelon -3:44:40 - LMT 1911 May 15 # St Pierre +Zone America/Miquelon -3:44:40 - LMT 1911 Jun 15 # St Pierre -4:00 - AST 1980 May -3:00 - -03 1987 -3:00 Canada -03/-02 diff --git a/southamerica b/southamerica index 19c7e456..344e67f3 100644 --- a/southamerica +++ b/southamerica @@ -1570,8 +1570,11 @@ Zone Atlantic/Stanley -3:51:24 - LMT 1890 -3:00 - -03 # French Guiana +# For the 1911/1912 establishment of standard time in French possessions, see: +# Société Française de Physique, Recueil de constantes physiques (1913), +# page 752, 18b. # Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone America/Cayenne -3:29:20 - LMT 1911 Jul +Zone America/Cayenne -3:29:20 - LMT 1911 Jul 1 -4:00 - -04 1967 Oct -3:00 - -03 -- 2.40.1

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NIST URLs for leap-seconds.list in leapseconds.awk
by PoolMUC＠web.de Jan. 10, 2024

Jan. 10, 2024

(apologies for earlier HTML mail, same message again in plain text (hopefully...)) Hi, After recent updates to leapseconds.awk to include IERS as a source for leap-seconds.list, one URL given for the file at NIST still is ftp://ftp.nist.gov/pub/time/leap-seconds.list: print "# This file is generated automatically from the data in the public-domain" print "# NIST/IERS format leap-seconds.list file, which can be copied from" print "# <https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list>" print "# or, in a variant with different comments, from" print "# <ftp://ftp.nist.gov/pub/time/leap-seconds.list>" print "# or <ftp://ftp.boulder.nist.gov/pub/time/leap-seconds.list>." However, at least for me, and at this time, the hostname ftp.nist.gov does not resolve. ftp.boulder.nist.gov does resolve. If others are seeing the same, and the condition persists, maybe the URL based on ftp.nist.gov should be removed. Thanks!

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Fwd: Bulletin C number 67
by Martin Burnicki Jan. 9, 2024

Jan. 9, 2024

Bulletin C number 67 is available, see also: https://hpiers.obspm.fr/iers/bul/bulc/bulletinc.dat At the same time, a new NTP leap second file has been made available by IERS (directory listing): https://hpiers.obspm.fr/iers/bul/bulc/ntp/ New file: https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.3913697179 As expected, no leap second is scheduled for the end of June 2024, but the expiration date of the file has been updated. As far as I see, the file also includes the changes recently discussed on this list, regarding a copyright info and some cosmetic changes. Martin -- Martin Burnicki Senior Software Engineer MEINBERG Funkuhren GmbH & Co. KG Email: martin.burnicki(a)meinberg.de Phone: +49 5281 9309-414 Linkedin: https://www.linkedin.com/in/martinburnicki/ Lange Wand 9, 31812 Bad Pyrmont, Germany Amtsgericht Hannover 17HRA 100322 Geschäftsführer/Managing Directors: Natalie Meinberg, Werner Meinberg, Andre Hartmann, Heiko Gerstung Websites: https://www.meinberg.de https://www.meinbergglobal.com

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2023d zdump with "min" year rule?
by Yoshito Umaoka Jan. 8, 2024

Jan. 8, 2024

Dear TZ Database maintainers, We (Unicode ICU project) preserve time zones deprecated in the TZ database. We keep old systemv file and include these zones in our library. For example, # SystemV time zones. # IANA tzdb file 'systemv' file has these SystemV/* zones commented out up to 2020a. # 'systemv' file was removed in 2020b. We keep them in this supplemental zone data # file for compatibility purpose. # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule SystemV min 1973 - Apr lastSun 2:00 1:00 D Rule SystemV min 1973 - Oct lastSun 2:00 0 S Rule SystemV 1974 only - Jan 6 2:00 1:00 D Rule SystemV 1974 only - Nov lastSun 2:00 0 S Rule SystemV 1975 only - Feb 23 2:00 1:00 D Rule SystemV 1975 only - Oct lastSun 2:00 0 S Rule SystemV 1976 max - Apr lastSun 2:00 1:00 D Rule SystemV 1976 max - Oct lastSun 2:00 0 S # Zone NAME GMTOFF RULES/SAVE FORMAT [UNTIL] Zone SystemV/AST4ADT -4:00 SystemV A%sT Zone SystemV/EST5EDT -5:00 SystemV E%sT Zone SystemV/CST6CDT -6:00 SystemV C%sT Zone SystemV/MST7MDT -7:00 SystemV M%sT Zone SystemV/PST8PDT -8:00 SystemV P%sT Zone SystemV/YST9YDT -9:00 SystemV Y%sT Zone SystemV/AST4 -4:00 - AST Zone SystemV/EST5 -5:00 - EST Zone SystemV/CST6 -6:00 - CST Zone SystemV/MST7 -7:00 - MST Zone SystemV/PST8 -8:00 - PST Zone SystemV/YST9 -9:00 - YST Zone SystemV/HST10 -10:00 - HST ICU data build feeds the extra zone file including above to zic, then run zdump to emit zone offset transitions. Then compare the output with the equivalent output produced by ICU library code. I’m currently working on TZ database 2023d and found this check is failing for SystemV/* with daylight saving time rule. All other zones work fine. With zdump in 2023d, all transitions before 1970 are not reported. For example: $ zdump -c 1900,1975 -V SystemV/AST4ADT emits the output below: SystemV/AST4ADT Sun Apr 26 05:59:59 1970 UT = Sun Apr 26 01:59:59 1970 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Apr 26 06:00:00 1970 UT = Sun Apr 26 03:00:00 1970 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 25 04:59:59 1970 UT = Sun Oct 25 01:59:59 1970 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 25 05:00:00 1970 UT = Sun Oct 25 01:00:00 1970 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Apr 25 05:59:59 1971 UT = Sun Apr 25 01:59:59 1971 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Apr 25 06:00:00 1971 UT = Sun Apr 25 03:00:00 1971 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 31 04:59:59 1971 UT = Sun Oct 31 01:59:59 1971 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 31 05:00:00 1971 UT = Sun Oct 31 01:00:00 1971 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Apr 30 05:59:59 1972 UT = Sun Apr 30 01:59:59 1972 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Apr 30 06:00:00 1972 UT = Sun Apr 30 03:00:00 1972 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 29 04:59:59 1972 UT = Sun Oct 29 01:59:59 1972 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 29 05:00:00 1972 UT = Sun Oct 29 01:00:00 1972 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Apr 29 05:59:59 1973 UT = Sun Apr 29 01:59:59 1973 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Apr 29 06:00:00 1973 UT = Sun Apr 29 03:00:00 1973 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 28 04:59:59 1973 UT = Sun Oct 28 01:59:59 1973 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Oct 28 05:00:00 1973 UT = Sun Oct 28 01:00:00 1973 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Jan 6 05:59:59 1974 UT = Sun Jan 6 01:59:59 1974 AST isdst=0 gmtoff=-14400 SystemV/AST4ADT Sun Jan 6 06:00:00 1974 UT = Sun Jan 6 03:00:00 1974 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Nov 24 04:59:59 1974 UT = Sun Nov 24 01:59:59 1974 ADT isdst=1 gmtoff=-10800 SystemV/AST4ADT Sun Nov 24 05:00:00 1974 UT = Sun Nov 24 01:00:00 1974 AST isdst=0 gmtoff=-14400 This is not a problem with 2023c. 2023c emits transitions starting year 1900 (the first year in the range) to 1975. I think these are only zones using rule line with “min” year rule. I suspect there is a regression bug in zdump when such rule is used. -Yoshito Umaoka

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Ministry of Digital Development and Communications, the Government of Mongolia
by fr Jan. 7, 2024

Jan. 7, 2024

Dear Sir/Ma'am, As we sent an inquiry regarding the switching time to the regular summer time matter earlier, could you please provide us some recommendations on below. The Government of Mongolia is planning to switch to the regular summer time from 22-26 March, 2024. Currently, the discussions are made within the Government as well as at the Parliament. We expect that final decision will be made in the October. Therefore, is it possible to arrange the switching process in the next 5 months? Is there any extraordinary cases like us or not? Or shall we make our changes in the September 2024? Thank you for your kind consideration in advance and hope to hear from you soon. Sincerely, Ms. Ariuntuul --- Foreign Cooperation Division Ministry of Digital Development and Communications The Government of Mongolia Tel: +976 51 260636 www.mddc.gov.mn

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