- tz - lists.iana.org

[PROPOSED] Document POSIX versions more carefully
by Paul Eggert Jan. 28, 2024

Jan. 28, 2024

Since the next POSIX will require support for TZDB Zone names in the TZ environment variable, be more careful about phrases like “POSIX-like TZ strings” in comments and documentation. Call them “POSIX.1-2017-like TZ strings” instead, to make it clearer that they’re the traditional POSIX form like TZ='GMT0BST,M3.5.0/1,M10.5.0' instead of the TZDB form like TZ='Europe/London'. --- Makefile | 19 ++++++++++--------- etcetera | 2 +- localtime.c | 16 +++++++++------- newstrftime.3 | 4 ++-- newtzset.3 | 4 ++-- private.h | 2 +- theory.html | 30 +++++++++++++++--------------- tz-link.html | 2 +- tzfile.5 | 28 +++++++++++++++------------- tzfile.h | 6 +++--- tzselect.ksh | 6 +++--- zic.8 | 10 +++++----- zic.c | 9 +++++---- 13 files changed, 72 insertions(+), 66 deletions(-) diff --git a/Makefile b/Makefile index 97a17314..d48354c7 100644 --- a/Makefile +++ b/Makefile @@ -53,7 +53,7 @@ DATAFORM= main LOCALTIME= Factory -# The POSIXRULES macro controls interpretation of POSIX-like TZ +# The POSIXRULES macro controls interpretation of POSIX-2017.1-like TZ # settings like TZ='EET-2EEST' that lack DST transition rules. # If POSIXRULES is '-', no template is installed; this is the default. # Any other value for POSIXRULES is obsolete and should not be relied on, as: @@ -274,7 +274,7 @@ LDLIBS= # -DTZ_DOMAINDIR=\"/path\" to use "/path" for gettext directory; # the default is system-supplied, typically "/usr/lib/locale" # -DTZDEFRULESTRING=\",date/time,date/time\" to default to the specified -# DST transitions for POSIX-style TZ strings lacking them, +# DST transitions for POSIX.1-2017-style TZ strings lacking them, # in the usual case where POSIXRULES is '-'. If not specified, # TZDEFRULESTRING defaults to US rules for future DST transitions. # This mishandles some past timestamps, as US DST rules have changed. @@ -340,9 +340,10 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # guess TM_GMTOFF from other macros; define NO_TM_GMTOFF to suppress this. # Similarly, if your system has a "zone abbreviation" field, define # -DTM_ZONE=tm_zone -# and define NO_TM_ZONE to suppress any guessing. Although these two fields -# not required by POSIX, a future version of POSIX is planned to require them -# and they are widely available on GNU/Linux and BSD systems. +# and define NO_TM_ZONE to suppress any guessing. +# Although these two fields are not required by POSIX.1-2017, +# POSIX 202x/D4 requires them and they are widely available +# on GNU/Linux and BSD systems. # # The next batch of options control support for external variables # exported by tzcode. In practice these variables are less useful @@ -352,7 +353,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # # -DHAVE_TZNAME=0 # do not support "tzname" # # -DHAVE_TZNAME=1 # support "tzname", which is defined by system library # # -DHAVE_TZNAME=2 # support and define "tzname" -# # to the "CFLAGS=" line. "tzname" is required by POSIX 1988 and later. +# # to the "CFLAGS=" line. "tzname" is required by POSIX.1-1988 and later. # # If not defined, the code attempts to guess HAVE_TZNAME from other macros. # # Warning: unless time_tz is also defined, HAVE_TZNAME=1 can cause # # crashes when combined with some platforms' standard libraries, @@ -362,8 +363,8 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # # -DUSG_COMPAT=0 # do not support # # -DUSG_COMPAT=1 # support, and variables are defined by system library # # -DUSG_COMPAT=2 # support and define variables -# # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by -# # Unix Systems Group code and are required by POSIX 2008 (with XSI) and later. +# # to the "CFLAGS=" line; "timezone" and "daylight" are inspired by Unix +# # Systems Group code and are required by POSIX.1-2008 and later (with XSI). # # If not defined, the code attempts to guess USG_COMPAT from other macros. # # # # To support the external variable "altzone", add @@ -427,7 +428,7 @@ GCC_DEBUG_FLAGS = -DGCC_LINT -g3 -O3 -fno-common \ # The name of a POSIX-like library archiver, its flags, C compiler, # linker flags, and 'make' utility. Ordinarily the defaults suffice. -# The commented-out values are the defaults specified by POSIX 202x/D3. +# The commented-out values are the defaults specified by POSIX.1-202x/D4. #AR = ar #ARFLAGS = -rv #CC = c17 diff --git a/etcetera b/etcetera index 865a220c..29fbed9b 100644 --- a/etcetera +++ b/etcetera @@ -5,7 +5,7 @@ # These entries are for uses not otherwise covered by the tz database. # Their main practical use is for platforms like Android that lack -# support for POSIX-style TZ strings. On such platforms these entries +# support for POSIX.1-2017-style TZ strings. On such platforms these entries # can be useful if the timezone database is wrong or if a ship or # aircraft at sea is not in a timezone. diff --git a/localtime.c b/localtime.c index 7613769f..02cc5ee5 100644 --- a/localtime.c +++ b/localtime.c @@ -7,7 +7,7 @@ /* ** Leap second handling from Bradley White. -** POSIX-style TZ environment variable handling from Guy Harris. +** POSIX.1-1988 style TZ environment variable handling from Guy Harris. */ /*LINTLIBRARY*/ @@ -106,7 +106,7 @@ static char const UNSPEC[] = "-00"; for ttunspecified to work without crashing. */ enum { CHARS_EXTRA = max(sizeof UNSPEC, 2) - 1 }; -/* Limit to time zone abbreviation length in POSIX-style TZ strings. +/* Limit to time zone abbreviation length in POSIX.1-2017-style TZ strings. This is distinct from TZ_MAX_CHARS, which limits TZif file contents. */ #ifndef TZNAME_MAXIMUM # define TZNAME_MAXIMUM 255 @@ -935,7 +935,8 @@ getoffset(register const char *strp, int_fast32_t *const offsetp) /* ** Given a pointer into a timezone string, extract a rule in the form -** date[/time]. See POSIX section 8 for the format of "date" and "time". +** date[/time]. See POSIX Base Definitions section 8.3 variable TZ +# for the format of "date" and "time". ** If a valid rule is not found, return NULL. ** Otherwise, return a pointer to the first character not part of the rule. */ @@ -1079,7 +1080,7 @@ transtime(const int year, register const struct rule *const rulep, } /* -** Given a POSIX section 8-style TZ string, fill in the rule tables as +** Given a POSIX.1-2017-style TZ string, fill in the rule tables as ** appropriate. */ @@ -1312,8 +1313,8 @@ tzparse(const char *name, struct state *sp, struct state const *basep) /* ** Transitions from DST to DDST ** will effectively disappear since - ** POSIX provides for only one DST - ** offset. + ** POSIX.1-2017 provides for only one + ** DST offset. */ if (isdst && !sp->ttis[j].tt_ttisstd) { sp->ats[i] += dstoffset - @@ -1483,7 +1484,8 @@ tzfree(timezone_t sp) ** ** If successful and SETNAME is nonzero, ** set the applicable parts of tzname, timezone and altzone; -** however, it's OK to omit this step if the timezone is POSIX-compatible, +** however, it's OK to omit this step +** if the timezone is compatible with POSIX.1-2017 ** since in that case tzset should have already done this step correctly. ** SETNAME's type is int_fast32_t for compatibility with gmtsub, ** but it is actually a boolean and its value should be 0 or 1. diff --git a/newstrftime.3 b/newstrftime.3 index 9fc68471..704318ea 100644 --- a/newstrftime.3 +++ b/newstrftime.3 @@ -91,11 +91,11 @@ as specified by brackets in the description. If a bracketed member name is followed by .q + , .B strftime -can use the named member even though POSIX-2017 does not list it; +can use the named member even though POSIX.1-2017 does not list it; if the name is followed by .q \*- , .B strftime -ignores the member even though POSIX-2017 lists it +ignores the member even though POSIX.1-2017 lists it which means portable code should set it. For portability, .BI * timeptr diff --git a/newtzset.3 b/newtzset.3 index 5d973749..b1384f32 100644 --- a/newtzset.3 +++ b/newtzset.3 @@ -216,7 +216,7 @@ except that POSIX.1-2017 does not allow a leading sign (\c .q "\*-" or .q "+" ). -As an extension to POSIX-1.2017, the hours part of +As an extension to POSIX.1-2017, the hours part of .I time can range from \-167 through 167; this allows for unusual rules such as @@ -230,7 +230,7 @@ is not given, is Here are some examples of .I TZ values that directly specify the timezone; they use some of the -extensions to POSIX-1.2017. +extensions to POSIX.1-2017. .TP .B EST5 stands for US Eastern Standard diff --git a/private.h b/private.h index b3d563d5..0dac6af4 100644 --- a/private.h +++ b/private.h @@ -973,7 +973,7 @@ enum { /* How many years to generate (in zic.c) or search through (in localtime.c). This is two years larger than the obvious 400, to avoid edge cases. - E.g., suppose a non-POSIX rule applies from 2012 on and has transitions + E.g., suppose a non-POSIX.1-2017 rule applies from 2012 on with transitions in March and September, plus one-off transitions in November 2013. If zic looked only at the last 400 years, it would set max_year=2413, with the intent that the 400 years 2014 through 2413 will be repeated. diff --git a/theory.html b/theory.html index 0fb8d66a..318b6c25 100644 --- a/theory.html +++ b/theory.html @@ -95,7 +95,7 @@ Group Base Specifications Issue 7</a>, IEEE Std 1003.1-2017, 2018 Edition. Because the database's scope encompasses real-world changes to civil timekeeping, its model for describing time is more complex than the -standard and daylight saving times supported by POSIX. +standard and daylight saving times supported by POSIX.1-2017. A <code><abbr>tz</abbr></code> timezone corresponds to a ruleset that can have more than two changes per year, these changes need not merely flip back and forth between two alternatives, and the rules themselves @@ -187,7 +187,7 @@ in decreasing order of importance: href="https://en.wikipedia.org/wiki/ASCII">ASCII</a> letters, '<code>.</code>', '<code>-</code>' and '<code>_</code>'. Do not use digits, as that might create an ambiguity with <a - href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#ta…">POSIX + href="https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap08.html#ta…">POSIX.1-2017 <code>TZ</code> strings</a>. A file name component must not exceed 14 characters or start with '<code>-</code>'. @@ -378,7 +378,7 @@ nowadays distributions typically use it and no great weight should be attached to whether a link is defined in <code>backward</code> or in some other file. The source file <code>etcetera</code> defines names that may be useful -on platforms that do not support POSIX-style <code>TZ</code> strings; +on platforms that do not support POSIX.1-2017-style <code>TZ</code> strings; no other source file other than <code>backward</code> contains links to its zones. One of <code>etcetera</code>'s names is <code>Etc/UTC</code>, @@ -426,7 +426,7 @@ in decreasing order of importance: expression <code>[-+[:alnum:]]{3,6}</code> should match the abbreviation. This guarantees that all abbreviations could have been specified by a - POSIX <code>TZ</code> string. + POSIX.1-2017 <code>TZ</code> string. </p> </li> <li> @@ -775,7 +775,7 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes the Western 06:00 to be 12:00. These practices are largely outside the scope of the <code><abbr>tz</abbr></code> code and data, which provide only limited support for date and time localization - such as that required by POSIX. + such as that required by POSIX.1-2017. If <abbr>DST</abbr> is not used a different time zone can often do the trick; for example, in Kenya a <code>TZ</code> setting like <code><-03>3</code> or <code>America/Cayenne</code> starts @@ -872,23 +872,23 @@ input is occasionally extended, and a platform may still be shipping an older <code>zic</code>. </p> -<h3 id="POSIX">POSIX properties and limitations</h3> +<h3 id="POSIX">POSIX.1-2017 properties and limitations</h3> <ul> <li> <p> - In POSIX, time display in a process is controlled by the + In POSIX.1-2017, time display in a process is controlled by the environment variable <code>TZ</code>. - Unfortunately, the POSIX + Unfortunately, the POSIX.1-2017 <code>TZ</code> string takes a form that is hard to describe and is error-prone in practice. - Also, POSIX <code>TZ</code> strings cannot deal with daylight + Also, POSIX.1-2017 <code>TZ</code> strings cannot deal with daylight saving time rules not based on the Gregorian calendar (as in Morocco), or with situations where more than two time zone abbreviations or <abbr>UT</abbr> offsets are used in an area. </p> <p> - The POSIX <code>TZ</code> string takes the following form: + The POSIX.1-2017 <code>TZ</code> string takes the following form: </p> <p> @@ -955,7 +955,7 @@ an older <code>zic</code>. </dl> <p> - Here is an example POSIX <code>TZ</code> string for New + Here is an example POSIX.1-2017 <code>TZ</code> string for New Zealand after 2007. It says that standard time (<abbr>NZST</abbr>) is 12 hours ahead of <abbr>UT</abbr>, and that daylight saving time @@ -966,7 +966,7 @@ an older <code>zic</code>. <pre><code>TZ='NZST-12NZDT,M9.5.0,M4.1.0/3'</code></pre> <p> - This POSIX <code>TZ</code> string is hard to remember, and + This POSIX.1-2017 <code>TZ</code> string is hard to remember, and mishandles some timestamps before 2008. With this package you can use this instead: </p> @@ -1004,7 +1004,7 @@ an older <code>zic</code>. limit phone calls to off-peak hours. </li> <li> - POSIX provides no convenient and efficient way to determine + POSIX.1-2017 provides no convenient and efficient way to determine the <abbr>UT</abbr> offset and time zone abbreviation of arbitrary timestamps, particularly for timezones that do not fit into the POSIX model. @@ -1031,14 +1031,14 @@ an older <code>zic</code>. </li> </ul> -<h3 id="POSIX-extensions">Extensions to POSIX in the +<h3 id="POSIX-extensions">Extensions to POSIX.1-2017 in the <code><abbr>tz</abbr></code> code</h3> <ul> <li> <p> The <code>TZ</code> environment variable is used in generating the name of a file from which time-related information is read - (or is interpreted à la POSIX); <code>TZ</code> is no longer + (or is interpreted à la POSIX.1-2017); <code>TZ</code> is no longer constrained to be a string containing abbreviations and numeric data as described <a href="#POSIX">above</a>. The file's format is <dfn><abbr>TZif</abbr></dfn>, diff --git a/tz-link.html b/tz-link.html index 5840f48f..c6181d92 100644 --- a/tz-link.html +++ b/tz-link.html @@ -114,7 +114,7 @@ Indiana, which switched from central to eastern time in 1991 and switched back in 2006. To use the database on an extended <a href="https://en.wikipedia.org/wiki/POSIX"><abbr -title="Portable Operating System Interface">POSIX</abbr></a> +title="Portable Operating System Interface">POSIX</abbr>.1-2017</a> implementation set the <code><abbr>TZ</abbr></code> environment variable to the location's full name, e.g., <code><abbr>TZ</abbr>="America/New_York"</code>.</p> diff --git a/tzfile.5 b/tzfile.5 index 55280282..867348d6 100644 --- a/tzfile.5 +++ b/tzfile.5 @@ -85,7 +85,7 @@ described in the file is associated with the time period starting with the same-indexed transition time and continuing up to but not including the next transition time. (The last time type is present only for consistency checking with the -POSIX-style TZ string described below.) +POSIX.1-2017-style TZ string described below.) These values serve as indices into the next field. .IP \(bu .B tzh_typecnt @@ -186,7 +186,8 @@ must also be set. .PP The standard/wall and UT/local indicators were designed for transforming a TZif file's transition times into transitions appropriate -for another time zone specified via a POSIX-style TZ string that lacks rules. +for another time zone specified via +a POSIX.1-2017-style TZ string that lacks rules. For example, when TZ="EET\*-2EEST" and there is no TZif file "EET\*-2EEST", the idea was to adapt the transition times from a TZif file with the well-known name "posixrules" that is present only for this purpose and @@ -215,13 +216,14 @@ the above header and data are followed by a second header and data, identical in format except that eight bytes are used for each transition time or leap second time. (Leap second counts remain four bytes.) -After the second header and data comes a newline-enclosed, -POSIX-TZ-environment-variable-style string for use in handling instants +After the second header and data comes a newline-enclosed string +in the style of the contents of a POSIX.1-2017 TZ environment variable, +for use in handling instants after the last transition time stored in the file or for all instants if the file has no transitions. -The POSIX-style TZ string is empty (i.e., nothing between the newlines) -if there is no POSIX-style representation for such instants. -If nonempty, the POSIX-style TZ string must agree with the local time +The TZ string is empty (i.e., nothing between the newlines) +if there is no POSIX.1-2017-style representation for such instants. +If nonempty, the TZ string must agree with the local time type after the last transition time if present in the eight-byte data; for example, given the string .q "WET0WEST,M3.5.0/1,M10.5.0" @@ -233,8 +235,8 @@ Also, if there is at least one transition, time type 0 is associated with the time period from the indefinite past up to but not including the earliest transition time. .SS Version 3 format -For version-3-format timezone files, the POSIX-TZ-style string may -use two minor extensions to the POSIX TZ format, as described in +For version-3-format timezone files, the TZ string may +use two minor extensions to the POSIX.1-2017 TZ format, as described in .BR newtzset (3). First, the hours part of its transition times may be signed and range from \-167 through 167 instead of the POSIX-required unsigned values @@ -352,7 +354,7 @@ version 2+ data even if the reader's native timestamps have only .IP \(bu Some readers designed for version 2 might mishandle timestamps after a version 3 or higher file's last transition, because -they cannot parse extensions to POSIX in the TZ-like string. +they cannot parse extensions to POSIX.1-2017 in the TZ-like string. As a partial workaround, a writer can output more transitions than necessary, so that only far-future timestamps are mishandled by version 2 readers. @@ -403,7 +405,7 @@ Some readers mishandle a transition if its timestamp has the minimum possible signed 64-bit value. Timestamps less than \-2**59 are not recommended. .IP \(bu -Some readers mishandle POSIX-style TZ strings that +Some readers mishandle TZ strings that contain .q "<" or @@ -431,12 +433,12 @@ Some readers mishandle TZif files that specify daylight-saving time UT offsets that are less than the UT offsets for the corresponding standard time. These readers do not support locations like Ireland, which -uses the equivalent of the POSIX TZ string +uses the equivalent of the TZ string .q "IST\*-1GMT0,M10.5.0,M3.5.0/1", observing standard time (IST, +01) in summer and daylight saving time (GMT, +00) in winter. As a partial workaround, a writer can output data for the -equivalent of the POSIX TZ string +equivalent of the TZ string .q "GMT0IST,M3.5.0/1,M10.5.0", thus swapping standard and daylight saving time. Although this workaround misidentifies which part of the year diff --git a/tzfile.h b/tzfile.h index 21ae37c1..3155010e 100644 --- a/tzfile.h +++ b/tzfile.h @@ -78,11 +78,11 @@ struct tzhead { ** time uses 8 rather than 4 chars, ** then a POSIX-TZ-environment-variable-style string for use in handling ** instants after the last transition time stored in the file -** (with nothing between the newlines if there is no POSIX representation for -** such instants). +** (with nothing between the newlines if there is no POSIX.1-2017 +** representation for such instants). ** ** If tz_version is '3' or greater, the above is extended as follows. -** First, the POSIX TZ string's hour offset may range from -167 +** First, the TZ string's hour offset may range from -167 ** through 167 as compared to the POSIX-required 0 through 24. ** Second, its DST start time may be January 1 at 00:00 and its stop ** time December 31 at 24:00 plus the difference between DST and diff --git a/tzselect.ksh b/tzselect.ksh index c56bc822..38941bbc 100644 --- a/tzselect.ksh +++ b/tzselect.ksh @@ -438,7 +438,7 @@ while eval ' doselect '"$quoted_continents"' \ "coord - I want to use geographical coordinates." \ - "TZ - I want to specify the timezone using the POSIX TZ format." \ + "TZ - I want to specify the timezone using a POSIX.1-2017 TZ string." \ "time - I know local time already." \ "now - Like \"time\", but configure only for timestamps from now on." continent=$select_result @@ -462,7 +462,7 @@ while case $continent in TZ) - # Ask the user for a POSIX TZ string. Check that it conforms. + # Ask the user for a POSIX.1-2017 TZ string. Check that it conforms. check_POSIX_TZ_string=' BEGIN { tz = substr(ARGV[1], 2) @@ -492,7 +492,7 @@ while read tz $AWK "$check_POSIX_TZ_string" ="$tz" do - say >&2 "'$tz' is not a conforming POSIX timezone string." + say >&2 "'$tz' is not a conforming POSIX.1-2017 timezone string." done TZ_for_date=$tz;; *) diff --git a/zic.8 b/zic.8 index 2f274d7b..0ad373a2 100644 --- a/zic.8 +++ b/zic.8 @@ -171,7 +171,7 @@ boundaries, particularly if causes a TZif file to contain explicit entries for .RI pre- hi transitions rather than concisely representing them -with an extended POSIX TZ string. +with an extended POSIX.1-2017 TZ string. Also see the .B "\*-b slim" option for another way to shrink output size. @@ -181,10 +181,10 @@ Generate redundant trailing explicit transitions for timestamps that occur less than .I hi seconds since the Epoch, even though the transitions could be -more concisely represented via the extended POSIX TZ string. +more concisely represented via the extended POSIX.1-2017 TZ string. This option does not affect the represented timestamps. Although it accommodates nonstandard TZif readers -that ignore the extended POSIX TZ string, +that ignore the extended POSIX.1-2017 TZ string, it increases the size of the altered output files. .TP .BI "\*-t " file @@ -245,10 +245,10 @@ for .PP The output file does not contain all the information about the long-term future of a timezone, because the future cannot be summarized as -an extended POSIX TZ string. For example, as of 2023 this problem +an extended POSIX.1-2017 TZ string. For example, as of 2023 this problem occurs for Morocco's daylight-saving rules, as these rules are based on predictions for when Ramadan will be observed, something that -an extended POSIX TZ string cannot represent. +an extended POSIX.1-2017 TZ string cannot represent. .PP The output contains data that may not be handled properly by client code designed for older diff --git a/zic.c b/zic.c index 70e8f0c7..00f00e30 100644 --- a/zic.c +++ b/zic.c @@ -2982,7 +2982,7 @@ rule_cmp(struct rule const *a, struct rule const *b) return a->r_dayofmonth - b->r_dayofmonth; } -/* Store into RESULT a POSIX TZ string that represent the future +/* Store into RESULT a POSIX.1-2017 TZ string that represent the future predictions for the zone ZPFIRST with ZONECOUNT entries. Return a compatibility indicator (a TZDB release year) if successful, a negative integer if no such TZ string exissts. */ @@ -3177,7 +3177,8 @@ outzone(const struct zone *zpfirst, ptrdiff_t zonecount) if (noise) { if (!*envvar) warning("%s %s", - _("no POSIX environment variable for zone"), + _("no POSIX.1-2017 environment variable" + " for zone"), zpfirst->z_name); else if (compat != 0) { /* Circa-COMPAT clients, and earlier clients, might @@ -3440,8 +3441,8 @@ outzone(const struct zone *zpfirst, ptrdiff_t zonecount) } if (do_extend) { /* - ** If we're extending the explicitly listed observations - ** for 400 years because we can't fill the POSIX-TZ field, + ** If we're extending the explicitly listed observations for + ** 400 years because we can't fill the POSIX.1-2017 TZ field, ** check whether we actually ended up explicitly listing ** observations through that period. If there aren't any ** near the end of the 400-year period, add a redundant -- 2.40.1

1 0

possible change to daylight saving rules in Palestine
by Paul Eggert Jan. 24, 2024

Jan. 24, 2024

Thank you for letting me know that the Palestinian cabinet is scheduled to respond this week to your address to them about daylight saving time during Ramadan. It would be convenient for cell phones and computers using the TZDB database if the cabinet decides to spring forward on April 13 at 02:00, and fall back on October 26 at 02:00, as that is what is predicted in TZDB. If the cabinet decides differently, I appreciate your offer to let us know as soon as possible. We are planning to issue a new TZDB release soon. It'd be helpful if any changes for Palestine could be incorporated in this new release, so that downstream users don't have the hassle of dealing with extra releases. I will cc this message to the tz mailing list to let people there know about this possible effect on our release schedule. If the cabinet needs reminding, I'll mention again that it's helpful to get a year's notice about unexpected changes, as discussed here: https://www.icann.org/en/blogs/details/how-time-zones-are-coordinated-13-03…

1 0

[PROPOSED] Update link to Palestine MTIT
by Paul Eggert Jan. 24, 2024

Jan. 24, 2024

* tz-link.html: Update link --- tz-link.html | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tz-link.html b/tz-link.html index 93c047cb..5840f48f 100644 --- a/tz-link.html +++ b/tz-link.html @@ -930,7 +930,7 @@ href="https://www.dia.govt.nz/Daylight-Saving-History">History of Daylight Saving</a>.</dd> <dt>Palestine</dt> <dd>The Ministry of Telecom and IT publishes a <a -href="https://mtit.pna.ps/Site/TimeZoon" +href="https://mtit.pna.ps/home/TimeZone" hreflang="ar">history of clock changes (in Arabic)</a>.</dd> <dt>Portugal</dt> <dd>The Lisbon Astronomical Observatory publishes a -- 2.40.1

1 0

Re: [tz] Time zone offset changing in Almaty and Qostanay, Kazakhstan
by Andrey.Kazakevich＠erg.kz Jan. 24, 2024

Jan. 24, 2024

Hello! How I can know when this change will be released? Have you some tracking or history of changes in database?

2 1

Washington state to permanent standard time?
by Arthur David Olson Jan. 24, 2024

Jan. 24, 2024

"Washington’s latest daylight saving time proposal would mean earlier summer sunsets." https://washingtonstatestandard.com/2024/01/16/washingtons-latest-daylight-… The article notes that Washington state adopted permanent daylight saving time in 2019, contingent on federal approval; that approval not having been provided, the current proposal is to use standard time year-round (a switch that does not require federal approval but allows the state to "ditch the switch"). The bill text is available at... https://app.leg.wa.gov/committeeschedules/Home/Document/264443#toolbar=0&na… ...and includes "...this act takes effect on November 4, 2024." (Meanwhile, I've yet to find the introduction of a time-change bill in the Maryland legislature; bills have been introduced the last few years.) @dashado

2 1

Time zone offset changing in Almaty and Qostanay, Kazakhstan
by Alexandr Uskov Jan. 24, 2024

Jan. 24, 2024

Hello, According act of the Government of the Republic of Kazakhstan from 2024-01-19 #20 (https://adilet.zan.kz/rus/docs/P2400000020 (russian language)) time offset for zones Asia/Almaty and Asia/Qostanay from Mar 1st 2024 00:00 (local time) must be set to UTC+5 instead of UTC+6. ~~~ wbr, Alexandr Uskov

2 1

Kazach
by Alexey Sharkov (KZ) Jan. 24, 2024

Jan. 24, 2024

Hello Decree of the Government of the Republic of Kazakhstan dated November 23, 2000 No. 1749 https://adilet.zan.kz/rus/docs/P2400000020 (Russian lang) 3-1. Акиматам городов Астаны, Алматы, Шымкента, Акмолинской, Алматинской, Жамбылской, Карагандинской, Костанайской, Павлодарской, Северо-Казахстанской, Туркестанской, Восточно-Казахстанской областей и областей Абай, Жетісу, Ұлытау в ночь с 29 февраля 2024 года на 1 марта 2024 года (в 00:00 часов) перевести местное время на 1 час назад.". For all Kazakhstan zones set local time back 1 hour night of February 29, 2024 to March 1, 2024 (at 00:00 hours) Zone Asia/Almaty Zone Asia/Qyzylorda Zone Asia/Qostanay Zone Asia/Aqtobe Zone Asia/Aqtau Zone Asia/Atyrau Zone Asia/Oral Internal Home Credit Bank Kazakhstan

1 0

strftime %s
by Dag-Erling Smørgrav Jan. 24, 2024

Jan. 24, 2024

Currently, strftime() implements %s by calling mktime() and then printing the result. This is fine when the struct tm passed to strftime() came from localtime() but not when it didn't. A better solution would be to call timegm() and then manually adjust the result. Of course that's only possible in the TM_GMTOFF case but that's still better than nothing. The first attachment is a program which demonstrates the issue. It should print the same value for %s in both cases but doesn't: % cc -Wall -Wextra -o strftime_s strftime_s.c % ./strftime_s local 1704903586 2024-01-10 17:19:46 CET gm 1704899986 2024-01-10 16:19:46 UTC The second attachment is my proposed fix. DES -- Dag-Erling Smørgrav - des(a)des.no

14 69

[PROPOSED 1/2] Update some tz-link links
by Paul Eggert Jan. 22, 2024

Jan. 22, 2024

* tz-link.html: Update some citations and remove some that no longer work. --- asia | 4 ++-- australasia | 2 +- tz-link.html | 33 ++++++++++++++------------------- 3 files changed, 17 insertions(+), 22 deletions(-) diff --git a/asia b/asia index a2055e6d..1a6fa4f8 100644 --- a/asia +++ b/asia @@ -3620,7 +3620,7 @@ Zone Asia/Hebron 2:20:23 - LMT 1900 Oct # Philippines -# From Paul Eggert (2018-11-18): +# From Paul Eggert (2024-01-21): # The Spanish initially used American (west-of-Greenwich) time. # It is unknown what time Manila kept when the British occupied it from # 1762-10-06 through 1764-04; for now assume it kept American time. @@ -3628,7 +3628,7 @@ Zone Asia/Hebron 2:20:23 - LMT 1900 Oct # Philippines, issued a proclamation announcing that 1844-12-30 was to # be immediately followed by 1845-01-01; see R.H. van Gent's # History of the International Date Line -# https://www.staff.science.uu.nl/~gent0113/idl/idl_philippines.htm +# https://webspace.science.uu.nl/~gent0113/idl/idl_philippines.htm # The rest of the data entries are from Shanks & Pottenger. # From Jesper Nørgaard Welen (2006-04-26): diff --git a/australasia b/australasia index a9e9eb4a..0e9c2592 100644 --- a/australasia +++ b/australasia @@ -2043,7 +2043,7 @@ Zone Pacific/Efate 11:13:16 - LMT 1912 Jan 13 # Vila # ordaining - by a masterpiece of diplomatic flattery - that # the Fourth of July should be celebrated twice in that year." # This happened in 1892, according to the Evening News (Sydney) of 1892-07-20. -# https://www.staff.science.uu.nl/~gent0113/idl/idl.htm +# https://webspace.science.uu.nl/~gent0113/idl/idl_alaska_samoa.htm # Although Shanks & Pottenger says they both switched to UT -11:30 # in 1911, and to -11 in 1950. many earlier sources give -11 diff --git a/tz-link.html b/tz-link.html index 84bea935..93c047cb 100644 --- a/tz-link.html +++ b/tz-link.html @@ -362,9 +362,6 @@ lets you see the <code><abbr>TZ</abbr></code> values directly.</li> <li><a href="https://www.convertit.com/Go/ConvertIt/World_Time/Current_Time.ASP">Current Time in 1000 Places</a> uses descriptions of the values.</li> -<li><a href="https://home.kpn.nl/vanadovv/time/TZworld.html">Complete -timezone information for all countries</a> -displays tables of <abbr>DST</abbr> rules. <li><a href="https://www.timeanddate.com/worldclock/">The World Clock – Worldwide</a> lets you sort zone names and convert times.</li> <li><a href="https://24timezones.com">24TimeZones</a> has a world @@ -666,9 +663,7 @@ available under a <abbr>BSD</abbr>-style license.</li> <ul> <li><a href="https://foxclocks.org">FoxClocks</a> is an extension for <a href="https://www.google.com/chrome/">Google -Chrome</a> and for <a -href="https://wiki.mozilla.org/Modules/Toolkit">Mozilla -Toolkit</a> applications like <a +Chrome</a>, <a href="https://www.mozilla.org/en-US/firefox/new/">Firefox</a> and <a href="https://www.mozilla.org/en-US/thunderbird/">Thunderbird</a>. It displays multiple clocks in the application window, and has a mapping @@ -826,9 +821,6 @@ coordinates?</a>" discusses other geolocation possibilities.</li> <li><a href="http://statoids.com/statoids.html">Administrative Divisions of Countries ("Statoids")</a> lists political subdivision data related to time zones.</li> -<li><a href="https://home.kpn.nl/vanadovv/time/Multizones.html">Time -zone boundaries for multizone countries</a> summarizes legal -boundaries between time zones within countries.</li> <li><a href="https://manifold.net/info/freestuff.shtml">Manifold Software – GIS and Database Tools</a> includes a Manifold-format map of world time zone boundaries distributed under the @@ -862,7 +854,7 @@ Lords</a> discusses how authoritarians manipulate civil time.</li> <li><a href="https://www.w3.org/TR/timezone/">Working with Time Zones</a> contains guidelines and best practices for software applications that deal with civil time.</li> -<li><a href="https://www.staff.science.uu.nl/~gent0113/idl/idl.htm">A History of +<li><a href="https://webspace.science.uu.nl/~gent0113/idl/idl.htm">A History of the International Date Line</a> tells the story of the most important time zone boundary.</li> <li><a href="http://statoids.com/tconcept.html">Basic Time @@ -875,7 +867,7 @@ Zone Concepts</a> discusses terminological issues behind time zones.</li> <dl> <dt>Australia</dt> <dd>The Parliamentary Library commissioned a <a -href="https://www.aph.gov.au/binaries/library/pubs/rp/2009-10/10rp10.pdf">research +href="https://parlinfo.aph.gov.au/parlInfo/download/library/prspub/359V6/upload_b…">research paper on daylight saving time in Australia</a>. The Bureau of Meteorology publishes a list of <a href="http://www.bom.gov.au/climate/averages/tables/dst_times.shtml">Implementation @@ -883,9 +875,9 @@ Dates of Daylight Savings Time within Australia</a>.</dd> <dt>Belgium</dt> <dd>The Royal Observatory of Belgium maintains a table of time in Belgium (in -<a href="https://www.astro.oma.be/GENERAL/INFO/nli001a.html" +<a href="https://robinfo.oma.be/nl/astro-info/tijd/" hreflang="nl">Dutch</a> and <a -href="https://www.astro.oma.be/GENERAL/INFO/fri001a.html" +href="https://robinfo.oma.be/fr/astro-info/heure/" hreflang="fr">French</a>).</dd> <dt>Brazil</dt> <dd>The Time Service Department of the National Observatory @@ -929,7 +921,7 @@ Congress has published a <a href="https://www.diputados.gob.mx/bibliot/publica/inveyana/polisoc/horver/index.…" hreflang="es">history of Mexican local time (in Spanish)</a>.</dd> <dt>Netherlands</dt> -<dd><a href="https://www.staff.science.uu.nl/~gent0113/wettijd/wettijd.htm" +<dd><a href="https://webspace.science.uu.nl/~gent0113/wettijd/wettijd.htm" hreflang="nl">Legal time in the Netherlands (in Dutch)</a> covers the history of local time in the Netherlands from ancient times.</dd> <dt>New Zealand</dt> @@ -986,14 +978,17 @@ neither supports nor refutes road safety benefits from shifts in time zones.</li> <li>Havranek T, Herman D, Irsova D. <a href="https://www.iaee.org/en/publications/ejarticle.aspx?id=3051">Does -daylight saving save electricity? A meta-analysis.</a> +daylight saving save electricity? A meta-analysis</a>. <em>Energy J.</em> 2018;39(2):35–61. doi:<a href="https://doi.org/10.5547/01956574.39.2.thav">10.5547/01956574.39.2.thav</a>. This analyzes research literature and concludes, "Electricity savings are larger for countries farther away from the equator, while subtropical regions consume more electricity because of <abbr>DST</abbr>."</li> -<li>Malow BA. It is time to abolish the clock change and adopt permanent -standard time in the United States: a Sleep Research Society position statement. +<li>Malow BA. <a +href="https://academic.oup.com/sleep/article/45/12/zsac236/6717940">It is time +to abolish the clock change and adopt permanent +standard time in the United States: +a Sleep Research Society position statement</a>. <em>Sleep.</em> 2022;45(12):zsac236. doi:<a href="https://doi.org/10.1093/sleep/zsac236">10.1093/sleep/zsac236</a>. After reviewing the scientific literature, the Sleep Research Society @@ -1002,13 +997,13 @@ advocates permanent standard time due to its health benefits. <a href="https://jcsm.aasm.org/doi/10.5664/jcsm.10898">Permanent standard time is the optimal choice for health and safety: an American Academy of Sleep Medicine position statement</a>. -<em>J Clin Sleep Med.</em> 2023-10-31. +<em>J Clin Sleep Med.</em> 2024;20(1):121–125. doi:<a href="https://doi.org/10.5664/jcsm.10898">10.5664/jcsm.10898</a>. The AASM argues for permanent standard time due to health and safety risks and economic costs of both <abbr>DST</abbr> transitions and permanent <abbr>DST</abbr>.</li> <li>Roenneberg T, Wirz-Justice A, Skene DJ <em>et al</em>. -<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7205184/">Why +<a href="https://journals.sagepub.com/doi/10.1177/0748730419854197">Why should we abolish Daylight Saving Time?</a> <em>J Biol Rhythms.</em> 2019;34(3):227–230. doi:<a href="https://doi.org/10.1177/0748730419854197">10.1177/0748730419854197</a>. -- 2.40.1

1 1

Kazakhstan (all parts) switching to UTC+5 on March 1, 2024
by Zhanbolat Raimbekov Jan. 21, 2024

Jan. 21, 2024

Kazakhstan (all parts) switching to UTC+5 on March 1, 2024 https://www.gov.kz/memleket/entities/mti/press/news/details/688998?lang=ru

5 9

[PATCH] Asia/Ho_Chi_Minh: Correct 1955 transition
by Đoàn Trần Công Danh Jan. 20, 2024

Jan. 20, 2024

While we're at it, updating source for 1959 transition. Ordinance 46 of 1955, first article read: Kể từ ngày mồng 1 tháng bảy năm 1955, giờ chính-thức ở Việt-nam là giờ của thời đạo thứ bảy. >From the 1955-07-01, the offical time in Vietnam is the time of the +07 timezone. ... lùi chậm sáu mươi phút, trong đêm hôm 30 tháng sáu năm 1955, rạng mặt ngày mồng 1 tháng bảy năm 1955 lúc một giờ sáng. ... move back 60 minutes, in the night of 1955-06-30, early morning of 1955-07-01 at 1AM. Decree 362-TTP of 1959, first article read: Kể từ ngày mồng 1 tháng giêng d.l. năm 1960, giờ chánh thức và pháp định ở Việt-nam được đặt nhanh hơn giờ của thời-đạo thứ bảy sáu mươi phút. >From the 1st of January 1960, de facto and de jure time in Vietnam will be faster than the +07 timezone, 60 minutes. ... vặn nhanh lên sáu mươi phút lúc 23 giờ đêm hôm 31 tháng chạp d.l. năm 1959, rạng mặt ngày mồng 1 tháng giêng d.l. năm 1960. ... fast forward 60 minutes at 23:00 of the night of 1959-12-31, early morning of 1960-01-01. --- NEWS | 3 +++ asia | 14 +++++++++++++- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/NEWS b/NEWS index 653512fa..705a2985 100644 --- a/NEWS +++ b/NEWS @@ -8,6 +8,9 @@ Unreleased, experimental changes Changes to past timestamps + In 1955, Asia/Ho_Chi_Minh's transitions occurred at 01:00 the + next day. (Reported by Đoàn Trần Công Danh.) + From 1947 through 1949, Toronto's transitions occurred at 02:00 not 00:00. (Thanks to Chris Walton.) diff --git a/asia b/asia index 8028c06e..db0c90e3 100644 --- a/asia +++ b/asia @@ -4088,6 +4088,18 @@ Zone Asia/Tashkent 4:37:11 - LMT 1924 May 2 # It also mentions a 1945-03-29 decree (by a Japanese Goveror-General) # to set the time zone to +09, but does not say whether that decree # merely legalized an earlier change to +09. +# +# July 1955 transition: +# Ngô Đình Diệm, Công Báo Việt Nam, No. 92 (1955-07-02), page 1780-1781 +# Ordinance (Dụ) No. 46 (1955-06-25) +# http://ddsnext.crl.edu/titles/32341#?c=0&m=29&s=0&cv=4&r=0&xywh=-89%2C342%2… +# It says that on 1955-07-01 at 01:00, South Vietnam moved back 1 hour (to +07). +# +# December 1959 transition: +# Ngô Đình Diệm, Công Báo Việt Nam Cộng Hòa, 1960 part 1 (1960-01-02), page 62 +# Decree (Sắc lệnh) No. 362-TTP (1959-12-30) +# http://ddsnext.crl.edu/titles/32341#?c=0&m=138&s=0&cv=793&r=0&xywh=-54%2C15… +# It says that on 1959-12-31 at 23:00, South Vietnam moved forward 1 hour (to +08). # Zone NAME STDOFF RULES FORMAT [UNTIL] @@ -4098,7 +4110,7 @@ Zone Asia/Ho_Chi_Minh 7:06:30 - LMT 1906 Jul 1 8:00 - +08 1945 Mar 14 23:00 9:00 - +09 1945 Sep 1 24:00 7:00 - +07 1947 Apr 1 - 8:00 - +08 1955 Jul 1 + 8:00 - +08 1955 Jul 1 01:00 7:00 - +07 1959 Dec 31 23:00 8:00 - +08 1975 Jun 13 7:00 - +07 -- 2.43.0.422.g5e73029237

2 1

Fwd: Dave Mills has passed away
by Marshall Eubanks Jan. 19, 2024

Jan. 19, 2024

Sad news. ---------- Forwarded message --------- From: Lars Eggert <lars(a)eggert.org> Date: Fri, Jan 19, 2024 at 12:12 PM Subject: Fwd: Dave Mills has passed away To: <ietf(a)ietf.org> Sad news. -- Sent from a mobile device; please excuse typos. Begin forwarded message: From: vinton cerf <vgcerf(a)gmail.com> Date: January 19, 2024 at 03:39:37 GMT+2 To: Andrew Sullivan <sullivan(a)isoc.org> Cc: Warren Kumari <warren(a)kumari.net>, John C Klensin <klensin(a)jck.com>, Hans-Werner Braun <hwb(a)ucsd.edu>, Dan Lynch <dan(a)lynch.com>, Stephen Kent <stkent(a)verizon.net> Subject: Dave Mills has passed away Please relay to IAB, IETF, IRTF and Hall of Fame His daughter, Leigh, just sent me the news that Dave passed away peacefully on January 17, 2024. He was such an iconic element of the early Internet. Network Time Protocol, the Fuzzball routers of the early NSFNET, INARG taskforce lead, COMSAT Labs and University of Delaware and so much more. vint

1 0

Kazakhstan (all parts) switching to UTC+5 on March 1, 2024 (officially accepted the law)
by Zhanbolat Raimbekov Jan. 19, 2024

Jan. 19, 2024

Kazakhstan (all states/oblasts) switching to UTC+5 on March 1, 2024 at 00:00 Currently, Kazakhstan has two time zones +5 and +6. +6 will switch to +5 on March 1, 2024 at midnight. https://www.gov.kz/memleket/entities/mti/press/news/details/688998?lang=ru (Updated 19 Jan, 2024) -- Zhanbolat Raimbekov

1 0

Kazakhstan to switch to a single time zone on March 1, 2024
by wtz＠worldtimezone.com Jan. 19, 2024

Jan. 19, 2024

According to a different news and the official web site for the Ministry of Trade and Integration of the Republic of Kazakhstan: https://en.inform.kz/news/kazakhstan-to-switch-to-single-hour-zone-mar-1-54… https://akipress.com/news:755336:Single_time_zone_to_be_set_in_Kazakhstan_f… Official web site for the Ministry of Trade and Integration of the Republic of Kazakhstan Kazakhstan to switch to a single time zone (updated text in Russian as of Jan 19, 2024) https://www.gov.kz/memleket/entities/mti/press/news/details/688998?lang=ru [1] (Dec 14, 2023 Press center / Media) https://en.inform.kz/news/kazakhstan-to-switch-to-single-hour-zone-mar-1-54… Single Time Zone in Kazakhstan: A working group of scientists met with public activists in East Kazakhstan Oblast https://www.gov.kz/memleket/entities/mti/press/media/details/42218?lang=en and our link on https://www.worldtimezone.com/dst_news/dst_news_kazakhstan01.html Kazakhstan will switch to the single time zone at 00:00 on March 1, 2024, to introduce the UTC+05.00 time throughout the country, Kazinform News Agency reports. According to the decree as of November 23, 2000, the akimats of Astana, Almaty and Shymkent cities, as well as Akmola, Almaty, Zhambyl, Karaganda, Kostanay, Pavlodar, North Kazakhstan, Turkistan, East Kazakhstan, Abai, Zhetysu, and Ulytau regions, have to turn the clock back an hour in the night of February 29th to March 1st at 00.00. As of today, there are two time zones in Kazakhstan UTC+5 and UTC+6. Regards, Alexander Krivenyshev, WorldTimeZone.com Links: ------ [1] https://www.gov.kz/memleket/entities/mti/press/news/details/688998?lang=ru

1 0

Kazakhstan time zone changes on Feb. 29th
by Ivan Ryzhov Jan. 19, 2024

Jan. 19, 2024

1 0

Kazakhstan switches to UTC+5
by Pavel Starosek Jan. 19, 2024

Jan. 19, 2024

Hello, Today government agencies announced a change in time zone from UTC+6 to UTC+5 from 00:00 on March 1, 2024. After this Kazakhstan will have a single time zone. https://www.gov.kz/memleket/entities/mti/press/news/details/688998?lang=ru > Amendments have been made to the Government Decree “On the procedure for calculating time on the territory of the Republic of Kazakhstan”. According to the changes, the use of a single time zone throughout the country is established from 00:00 on March 1, 2024. > Thus, the 5th time zone (UTC+5) will be applied to the entire territory of the Republic of Kazakhstan. > Today in Kazakhstan there are two time zones UTC+5 and UTC+6. Most of the country's territory (with the exception of the western regions) is located in the UTC+6 zone. > The resolution is subject to official publication and comes into force on March 1, 2024. -- Thanks, Pavel Starosek

1 0

Canadian Geographic Matthews & Vincent article URI updates
by Brian Inglis Jan. 17, 2024

Jan. 17, 2024

Current tzdata contains northamerica:1413: # From Paul Eggert (2014-10-18): # H. David Matthews and Mary Vincent's map # "It's about TIME", _Canadian Geographic_ (September-October 1998) # http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp # contains detailed boundaries for regions observing nonstandard # time and daylight saving time arrangements in Canada circa 1998. Could update this with the Archive.org URIs below or possibly move it to tz-art.html section "Books, plays and magazines": H. David Matthews and Mary Vincent, earliest working Archive.org URIs: https://web.archive.org/web/20071217083933/http://www.canadiangeographic.ca… https://web.archive.org/web/19990827055050/https://canadiangeographic.ca/SO… "It's about TIME", "À la Carte" column, Canadian Geographic Magazine, September/October 1998 issue; original CanGeog URIs: http://www.canadiangeographic.ca/Magazine/SO98/alacarte.asp https://canadiangeographic.ca/SO98/geomap.htm Summarizes Canada's time zone rules, boundaries, deviations, and exceptions with maps. In each pair of URIs for Archive.org and CanGeog original, the 1st URI is for article content within that issue's column context, the 2nd URI is the article content alone. -- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada La perfection est atteinte Perfection is achieved non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut -- Antoine de Saint-Exupéry

3 3

[PROPOSED] Draft next POSIX has tm_gmtoff, tm_zone
by Paul Eggert Jan. 14, 2024

Jan. 14, 2024

* private.h (TM_GMTOFF, TM_ZONE): Treat draft next POSIX like glibc etc., since it requires tm_gmtoff and tm_zone. --- private.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/private.h b/private.h index 07316289..8eff90b7 100644 --- a/private.h +++ b/private.h @@ -768,7 +768,8 @@ time_t posix2time(time_t); /* Infer TM_ZONE on systems where this information is known, but suppress guessing if NO_TM_ZONE is defined. Similarly for TM_GMTOFF. */ -#if (defined __GLIBC__ \ +#if (200809 < _POSIX_VERSION \ + || defined __GLIBC__ \ || defined __tm_zone /* musl */ \ || defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__ \ || (defined __APPLE__ && defined __MACH__)) -- 2.40.1

2 4

[PATCH] Asia/Ho_Chi_Minh 1945-09 Source added
by Đoàn Trần Công Danh Jan. 14, 2024

Jan. 14, 2024

A new source for the transition of Asia/Ho_Chi_Minh and Asia/Hanoi from +09 to +07 was found. The source is Việt Nam Dân Quốc Công Báo (Official Journal of the People Republic of Viet Nam). Original text and translation: Bộ-trưởng bộ Nội-vụ Minister of Ministry of Internal Affairs Chiểu chi nghị-định cựu Toàn-Quyền Đông-Dương ngày 29 tháng 3 năm 1945 ấn định giờ chính thức ở Đông-Dương, Based on the decision of the former Governor-General of the (French) Indochina on the 29th of March, 1945, that dictated the official timezone in Indochina, Nghị-Định Decided Điều thứ nhất: Trong toàn cõi nước Việt-Nam, giờ chính thức do nghị định ngày 29 tháng 3 năm 1945 ấn định, sẽ lui lại hai giờ, kể từ 24 giờ, ngày mồng 1 tháng 9 năm 1945. Article 1: In the whole Viet-Nam, the official timezone as dictated by decision on the 29th of March 1945, would move back 2 hours, effective at 24:00 on the 1st of September 1945 Điều thứ hai: Nghị-định cựu Toàn-Quyền Đông-Dương ngày 29 tháng 3 năm 1945 kể trên từ nay sẽ bãi bỏ. Article 2: The Decision on the 29 of March 1945 of the former Governor-General of the Indochina would be canceled from now on. Hà-nội ngày mồng 1 tháng 9 năm 1945 --- asia | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/asia b/asia index 04526c19..e8317127 100644 --- a/asia +++ b/asia @@ -4058,6 +4058,15 @@ Zone Asia/Tashkent 4:37:11 - LMT 1924 May 2 # which is used below even though the modern-day Phù Liễn Observatory # is closer to 07:06:31. Abbreviate Phù Liễn Mean Time as PLMT. # +# In September 1, 1945, Vietnam moved back 2 hours, back to GMT+7. +# In that very decision, they mentioned an old decision to change timezone +# in March 29, 1945. It's unknown whether Vietnam moved to GMT+9 either on +# or after March 29, 1945; or the decision (by a Japanese Goveror-General) +# only legalised the change to GMT+9 earlier. +# Source: Việt Nam Dân Quốc Công Báo, No. 1, September 29, 1945 +# Archived by National Library of Viet Nam +# http://baochi.nlv.gov.vn/baochi/cgi-bin/baochi?a=d&d=JwvzO19450929.2.5&srpo… +# # The following transitions occurred in Indochina in general (before 1954) # and in South Vietnam in particular (after 1954): # To 07:00 on 1911-05-01. -- 2.43.0.422.g5e73029237

2 1

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

16 66

[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

2 2

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

Jan. 10, 2024

3 2

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.]

3 5

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.

3 4

[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

1 0