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Negative leap second in main stream media.
by Arthur David Olson March 28, 2024

March 28, 2024

'...although the core is causing the planet to spin faster, the planetary shape changes caused by a warming climate are slowing that process. Absent this effect...the overall acceleration of the planet’s rotation might require timekeepers to insert a “negative leap second” at the end of 2026. Because of climate change, that might not be necessary until 2029.' "Climate change is altering Earth’s rotation enough to mess with our clocks," Washington Post, 2024-03-28. Behind a paywall: https://www.washingtonpost.com/science/2024/03/27/leap-second-melting-poles… @dashdashado

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Asia/Tehran +3:30
by Mohammad Farshad March 28, 2024

March 28, 2024

Dear Sir/Madam I think the time zone of Theran/Iran is not correct in the 2024a version. "After returning to the standard time on 22 September 2022, the Iran Government elected to remain permanently in the standard time, cancelling daylight saving time. Hence, Iran will permanently remain at UTC + 3:30 time zone going forward." Link: Iran 2023 time zone update now available - Microsoft Community Hub <https://techcommunity.microsoft.com/t5/daylight-saving-time-time-zone/iran-….> Best regards, Mohammad farshad

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Re: [tz] Asia/Tehran +3:30
by brian.inglis＠systematicsw.ab.ca March 27, 2024

March 27, 2024

On 2024-03-26 14:49, Tim Parenti via tz wrote: > On Tue, 26 Mar 2024 at 15:00, Mohammad Farshad via tz wrote: >> I think the time zone of Theran/Iran is not correct in the 2024a version. > Our data has Iran on UTC+3:30 year-round from 2023 onward. If this is > incorrect, please point us to official announcements that indicate otherwise. > Alternatively, if you believe you're seeing incorrect timestamps for Iran > generated by 2024a, please provide more detail on the precise behavior > you're observing and the system you're running on. >> "After returning to the standard time on 22 September 2022, the Iran >> Government elected to remain permanently in the standard time, cancelling >> daylight saving time. Hence, Iran will permanently remain at UTC + 3:30 time >> zone going forward." > Note that our Iran DST rules stop after 2022. This change was made on > 2022-05-10 and released in version 2022b on 2022-08-10: > <https://github.com/eggert/tz/commit/66b18d9835dda089d65349c86e7851c4f0746e09> $ head /usr/share/doc/tzdata/version 2024a # Last transitions: $ zdump -Vc2022,2025 Asia/Tehran Asia/Tehran Mon Mar 21 20:29:59 2022 UT = Mon Mar 21 23:59:59 2022 +0330 isdst=0 gmtoff=12600 Asia/Tehran Mon Mar 21 20:30:00 2022 UT = Tue Mar 22 01:00:00 2022 +0430 isdst=1 gmtoff=16200 Asia/Tehran Wed Sep 21 19:29:59 2022 UT = Wed Sep 21 23:59:59 2022 +0430 isdst=1 gmtoff=16200 Asia/Tehran Wed Sep 21 19:30:00 2022 UT = Wed Sep 21 23:00:00 2022 +0330 isdst=0 gmtoff=12600 Not every system uses tzdata, nor keeps it up to date, and some systems take longer to get changes into production releases. We are aware of the sometimes months long update, test, release pipeline delays with Apple, Oracle (and Java), and other vendor tzdata updates. MS just announced in their DST blog "interim" guidance on: - 2021 Samoa stopping DST will be in Windows 2024 March preview or April security updates; and previously for - 2022 October Syria stopping DST a year later in 2023 October/November Windows updates! https://techcommunity.microsoft.com/t5/daylight-saving-time-time-zone/inter… https://techcommunity.microsoft.com/t5/daylight-saving-time-time-zone/inter… The "interim" normally means guidance issued shortly after the government announcement, before the MS Windows update; *not* long after the announcement, and just before they finally figured out how to make the ridiculously delayed updates! I wonder how they do with .NET (uses tzdata), Outlook, Exchange, MS-SQL? -- 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

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mktime() clarification
by Dag-Erling Smørgrav March 26, 2024

March 26, 2024

Both the C standard and POSIX state that mktime() returns -1 on failure; POSIX additionally states that it sets errno. However, since -1 is also a valid result (representing 23:59:59 UTC on 1969-12-31) and POSIX never guarantees that a successful call does not modify errno, it seems to me that the only reliable way to determine whether mktime() succeeded, within the bounds of the aforementioned standards, is to set tm_wday or tm_yday to an out-of-bounds value (e.g. -1) prior to calling mktime() and check whether it has been modified on return. As far as I can tell, this has been the case ever since mktime() was introduced in POSIX.1 in 1988 and XPG3 and ANSI C in 1989. Am I wrong? Would it be a mistake to state this outright in the appropriate manual page? DES -- Dag-Erling Smørgrav - des(a)des.no

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TZ Environment Variable in Australia/Lord_Howe
by Bill Seymour March 20, 2024

March 20, 2024

I notice in Australia/Lord_Howe that the TZ environment variable in the compiled TZif file is: <+1030>-10:30<+11>-11,M10.1.0,M4.1.0 Are the signs backwards, i.e., should the signs between the angle brackets be the wrong ones and the offsets after the '>' be the right ones? The Zone record in the 2024a release is: Zone Australia/Lord_Howe 10:36:20 - LMT 1895 Feb 10:00 - AEST 1981 Mar 10:30 LH +1030/+1130 1985 Jul 10:30 LH +1030/+11 --Bill Seymour

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Ubuntu drops old-style links
by Matt Johnson-Pint March 19, 2024

March 19, 2024

I just learned that Ubuntu Noble (24.04) decided to intentionally split the tzdata package. Old-style links such as US/Eastern are no longer included by default, but are available in the tzdata-legacy package instead. Just thought I'd share. I wonder if other distributions / platforms / libraries will follow suit. What do y'all think? See: https://bugs.launchpad.net/ubuntu/+source/tzdata/+bug/2058249 https://stackoverflow.com/questions/78180695/unrecognized-time-zone -Matt

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troff(1) warning on zic(8)
by Alejandro Colomar March 17, 2024

March 17, 2024

Hi Paul, I've been looking at tz.git to fix some indentation issues, and saw this warning in one page: $ man ./zic.8 troff:<standard input>:357: warning: unbalanced 'el' request $ type man man is a function man () { if command man "$@"; then command man --warnings=w "$@" > /dev/null; fi } Have a lovely day! Alex -- <https://www.alejandro-colomar.es/>

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[PATCH] tzfile.5: Fix indentation
by Alejandro Colomar March 17, 2024

March 17, 2024

RS after IP, if the indentation amount is not specified, takes the same indentation that IP had. The values being used were wrong, and by removing them, we're fixing the indentation of the page. Cc: "G. Branden Robinson" <branden(a)debian.org> Cc: Paul Eggert <eggert(a)cs.ucla.edu> Signed-off-by: Alejandro Colomar <alx(a)kernel.org> --- tzfile.5 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tzfile.5 b/tzfile.5 index 867348d6..ef0c14e6 100644 --- a/tzfile.5 +++ b/tzfile.5 @@ -42,7 +42,7 @@ .SH DESCRIPTION Fifteen bytes containing zeros reserved for future use. .IP \(bu Six four-byte integer values, in the following order: -.RS "\w' \(bu 'u" +.RS .TP "\w' 'u" .B tzh_ttisutcnt The number of UT/local indicators stored in the file. @@ -134,7 +134,7 @@ .SH DESCRIPTION is in the range [\-89999, 93599] (i.e., more than \-25 hours and less than 26 hours); this allows easy support by implementations that already support the POSIX-required range [\-24:59:59, 25:59:59]. -.RS "\w' 'u" +.RS .IP \(bu "\w'\(bu 'u" .B tzh_charcnt bytes that represent time zone designations, -- 2.43.0

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Bug#1067022: man2html: Segmentation fault with tzfile(5)
by Alejandro Colomar March 16, 2024

March 16, 2024

Package: man2html Version: 1.6g-16 Severity: normal Tags: upstream X-Debbugs-Cc: Alejandro Colomar <alx(a)kernel.org>, Paul Eggert <eggert(a)cs.ucla.edu>, "G. Branden Robinson" <branden(a)debian.org>, linux-man(a)vger.kernel.org, groff(a)gnu.org, tz(a)iana.org Dear Maintainer, The page tzfile(5) from tzdb-2024a manages to consistently produce a Segmentation fault with man2html(1). Below is a reproducer: alx@debian:~/tmp$ wget https://data.iana.org/time-zones/releases/tzdb-2024a.tar.lz 2>/dev/null alx@debian:~/tmp$ tar xf tzdb-2024a.tar.lz alx@debian:~/tmp$ man2html tzdb-2024a/tzfile.5 Content-type: text/html; charset=UTF-8 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <HTML><HEAD><TITLE>Man page of tzfile</TITLE> </HEAD><BODY> <H1>tzfile</H1> Section: File Formats (5)<BR>Updated: <BR><A HREF="#index">Index</A> <A HREF="/cgi-bin/man/man2html">Return to Main Contents</A><HR> <A NAME="lbAB"> </A> <H2>NAME</H2> tzfile - timezone information <A NAME="lbAC"> </A> <H2>DESCRIPTION</H2> The timezone information files used by <B><A HREF="/cgi-bin/man/man2html?3+tzset">tzset</A></B>(3) are typically found under a directory with a name like <I>/usr/share/zoneinfo</I>. These files use the format described in Internet RFC 8536. Each file is a sequence of 8-bit bytes. In a file, a binary integer is represented by a sequence of one or more bytes in network order (bigendian, or high-order byte first), with all bits significant, a signed binary integer is represented using two's complement, and a boolean is represented by a one-byte binary integer that is either 0 (false) or 1 (true). The format begins with a 44-byte header containing the following fields: Segmentation fault alx@debian:~/tmp$ dpkg -l | grep man2html ii man2html 1.6g-16 amd64 browse man pages in your web browser ii man2html-base 1.6g-16 amd64 convert man pages into HTML format I've refreshed this page today, and the previous version I used didn't have this crash. Below is the part of the diff that I think is responsible for the crash: diff --git a/man5/tzfile.5 b/man5/tzfile.5 index 45afecc10..867348d67 100644 --- a/man5/tzfile.5 +++ b/man5/tzfile.5 @@ -26,23 +26,24 @@ .SH DESCRIPTION and a boolean is represented by a one-byte binary integer that is either 0 (false) or 1 (true). The format begins with a 44-byte header containing the following fields: -.IP * 2 +.RS "\w' 'u" +.IP \(bu "\w'\(bu 'u" The magic four-byte ASCII sequence .q "TZif" identifies the file as a timezone information file. BTW, I noticed that the upstream homepage is dead: <http://users.actrix.gen.nz/michael/vhman2html.html>. Is this project defunct? Have a lovely day! Alex -- System Information: Debian Release: trixie/sid APT prefers unstable APT policy: (500, 'unstable'), (1, 'experimental') Architecture: amd64 (x86_64) Kernel: Linux 6.8.0-rc7-alx-dirty (SMP w/24 CPU threads; PREEMPT) Locale: LANG=C.utf8, LC_CTYPE=C.utf8 (charmap=UTF-8), LANGUAGE not set Shell: /bin/sh linked to /usr/bin/dash Init: systemd (via /run/systemd/system) LSM: AppArmor: enabled Versions of packages man2html depends on: ii debconf [debconf-2.0] 1.5.86 ii gawk 1:5.2.1-2 ii libc6 2.37-15.1 ii lynx 2.9.0rel.0-2+b1 ii man-db 2.12.0-3 ii man2html-base 1.6g-16 ii sensible-utils 0.0.22 man2html recommends no packages. Versions of packages man2html suggests: ii firefox-esr [www-browser] 115.8.0esr-1+b1 ii lynx [www-browser] 2.9.0rel.0-2+b1 pn swish++ <none> ii w3m [www-browser] 0.5.3+git20230121-2+b3 -- debconf information: man2html/index_manpages: true

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People Hate Daylight Saving. Science Tells Us Why.
by Brian Inglis March 14, 2024

March 14, 2024

A summary of various studies and opinions: https://undark.org/2024/03/11/time-zones-daylight-saving/ -- 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

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