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Diffstat (limited to 'contrib/tzcode/tz-link.html')
| -rw-r--r-- | contrib/tzcode/tz-link.html | 113 |
1 files changed, 68 insertions, 45 deletions
diff --git a/contrib/tzcode/tz-link.html b/contrib/tzcode/tz-link.html index 9fb57c9058a9..be2aae5489d6 100644 --- a/contrib/tzcode/tz-link.html +++ b/contrib/tzcode/tz-link.html @@ -81,10 +81,11 @@ C Library</a> (used in title="Berkeley Software Distribution">BSD</abbr></a>, <a href="https://netbsd.org">Net<abbr>BSD</abbr></a>, <a href="https://www.openbsd.org">Open<abbr>BSD</abbr></a>, -<a href="https://www.chromium.org/chromium-os/">Chromium OS</a>, +<a href="https://www.chromium.org/chromium-os/">ChromiumOS</a>, <a href="https://cygwin.com">Cygwin</a>, <a href="https://mariadb.org">MariaDB</a>, <a href="https://en.wikipedia.org/wiki/MINIX">MINIX</a>, +<a href="https://musl.libc.org">musl libc</a>, <a href="https://www.mysql.com">MySQL</a>, <a href="https://en.wikipedia.org/wiki/WebOS"><abbr title="Web Operating System">webOS</abbr></a>, @@ -112,9 +113,9 @@ eastern time but with different <abbr>DST</abbr> rules in 1975; and other entries represent smaller regions like Starke County, Indiana, which switched from central to eastern time in 1991 and switched back in 2006. -To use the database on an extended <a +To use the database on a <a href="https://en.wikipedia.org/wiki/POSIX"><abbr -title="Portable Operating System Interface">POSIX</abbr>.1-2017</a> +title="Portable Operating System Interface">POSIX</abbr>.1-2024</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> @@ -192,9 +193,10 @@ After obtaining the code and data files, see the <code>README</code> file for what to do next. The code lets you compile the <code><abbr>tz</abbr></code> source files into machine-readable binary files, one for each location. The binary files -are in a special timezone information format (<dfn><abbr>TZif</abbr></dfn>) -specified by <a href="https://datatracker.ietf.org/doc/html/8536">Internet -<abbr>RFC</abbr> 8536</a>. +are in a special format specified by +<a href="https://datatracker.ietf.org/doc/html/8536">The +Time Zone Information Format (<abbr>TZif</abbr>)</a> +(Internet <abbr title="Request For Comments">RFC</abbr> 8536). The code also lets you read a <abbr>TZif</abbr> file and interpret timestamps for that location.</p> @@ -205,13 +207,11 @@ location.</p> <p> The <code><abbr>tz</abbr></code> code and data are by no means authoritative. If you find errors, please -send changes to <a href="mailto:tz@iana.org"><code>tz@iana.org</code></a>, -the time zone mailing list. You can also <a -href="https://mm.icann.org/mailman/listinfo/tz">subscribe</a> to it -and browse the <a -href="https://mm.icann.org/pipermail/tz/">archive of old -messages</a>. -<a href="https://tzdata-meta.timtimeonline.com/">Metadata for mailing list +email changes to <a href="mailto:tz@iana.org"><code>tz@iana.org</code></a>, +the time zone mailing list. See +<a href="https://lists.iana.org/postorius/lists/tz.iana.org/">the mailing +list's main page</a> to subscribe or to browse its archive of old messages. +<a href="https://tzdata-meta.timtimeonline.com">Metadata for mailing list discussions</a> and corresponding data changes can be generated <a href="https://github.com/timparenti/tzdata-meta">automatically</a>. </p> @@ -226,7 +226,7 @@ the process by tailoring the generic instructions in the <code><abbr>tz</abbr> README</code> file and installing the latest data yourself. System-specific instructions for installing the latest <code><abbr>tz</abbr></code> data have also been published -for <a href="https://developer.ibm.com/articles/au-aix-olson-time-zone/"><abbr>AIX</abbr></a>, +for <a href="https://www.ibm.com/support/pages/aix-time-zone-olson-tzdata-updates"><abbr>AIX</abbr></a>, <a href="https://source.android.com/devices/tech/config/timezone-rules">Android</a>, <a @@ -248,7 +248,7 @@ with lines terminated by <a href="https://en.wikipedia.org/wiki/Newline"><abbr title="linefeed">LF</abbr></a>, which can be modified by common text editors such as <a href="https://www.gnu.org/software/emacs/">GNU Emacs</a>, -<a href="https://wiki.gnome.org/Apps/Gedit">gedit</a>, and +<a href="https://gedit-technology.github.io/apps/gedit/">gedit</a>, and <a href="https://www.vim.org">vim</a>. Specialized source-file editing can be done via the <a href="https://packagecontrol.io/packages/zoneinfo">Sublime @@ -261,8 +261,8 @@ Studio Code</a>. <p> For further information about updates, please see <a href="https://datatracker.ietf.org/doc/html/rfc6557">Procedures for -Maintaining the Time Zone Database</a> (Internet <abbr -title="Request For Comments">RFC</abbr> 6557). More detail can be +Maintaining the Time Zone Database</a> (Internet <abbr>RFC</abbr> 6557). +More detail can be found in <a href="theory.html">Theory and pragmatics of the <code><abbr>tz</abbr></code> code and data</a>. <a href="https://a0.github.io/a0-tzmigration/">A0 TimeZone Migration</a> @@ -400,7 +400,7 @@ variant <a href="https://datatracker.ietf.org/doc/html/rfc6321">xCal</a> title="Extensible Markup Language">XML</abbr></a> format, and a variant <a href="https://datatracker.ietf.org/doc/html/rfc7265">jCal</a> (Internet <abbr>RFC</abbr> 7265) -uses <a href="https://www.json.org"><abbr +uses <a href="https://www.json.org/json-en.html"><abbr title="JavaScript Object Notation">JSON</abbr></a> format.</li> </ul> </section> @@ -413,7 +413,7 @@ distributions you can generally work around compatibility problems by running the command <code>make rearguard_tarballs</code> and compiling from the resulting tarballs instead.</p> <ul> -<li><a href="https://sourceforge.net/projects/vzic/">Vzic</a> is a <a +<li><a href="https://github.com/libical/vzic">Vzic</a> is a <a href="https://en.wikipedia.org/wiki/C_(programming_language)">C</a> program that compiles <code><abbr>tz</abbr></code> source into iCalendar-compatible VTIMEZONE files. @@ -440,11 +440,9 @@ transition in the <code><abbr>tz</abbr></code> database.</li> <li>The <a href="https://howardhinnant.github.io/date/tz.html">Time Zone Database Parser</a> is a <a href="https://en.wikipedia.org/wiki/C++">C++</a> parser and -runtime library with <a -href="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0355r7.html">API</a> -adopted by -<a href="https://en.wikipedia.org/wiki/C++20">C++20</a>, -the current iteration of the C++ standard. +runtime library with a <a +href="https://en.cppreference.com/w/cpp/chrono"><code>std::chrono</code> API</a> +that is a standard part of C++. It is freely available under the <abbr title="Massachusetts Institute of Technology">MIT</abbr> license.</li> <li><a id="ICU" href="https://icu.unicode.org">International Components for @@ -467,8 +465,8 @@ freely available under the <abbr>MIT</abbr> license.</li> <li>The <a href="https://www.oracle.com/java/technologies/javase/tzupdater-readme.html">TZUpdater tool</a> compiles <code><abbr>tz</abbr></code> source into the format used by -<a href="https://openjdk.java.net/">OpenJDK</a> and -<a href="https://jdk.java.net/">Oracle JDK</a>. +<a href="https://openjdk.org">OpenJDK</a> and +<a href="https://jdk.java.net">Oracle JDK</a>. Although its source code is proprietary, its executable is available under the <a href="https://www.oracle.com/a/tech/docs/tzupdater-lic.html">Java SE Timezone Updater License Agreement</a>.</li> @@ -490,7 +488,7 @@ are alternatives to TZUpdater. IANA Updater's license is unclear; ZIUpdater is licensed under the <abbr>GPL</abbr>.</li> <li><a href="https://github.com/MenoData/Time4A">Time4A: Advanced date and time library for Android</a> and -<a href="https://github.com/MenoData/Time4J/">Time4J: Advanced date, +<a href="https://github.com/MenoData/Time4J">Time4J: Advanced date, time and interval library for Java</a> compile <code><abbr>tz</abbr></code> source into a binary format. Time4A is available under the Apache License and Time4J is @@ -516,7 +514,7 @@ many of which also support runtimes lacking the <code>timeZone</code> option. href="https://github.com/formatjs/date-time-format-timezone"><code>Intl.DateTimeFormat</code> timezone polyfill</a> is freely available under a <abbr>BSD</abbr>-style license.</li> -<li>The <a href="https://date-fns.org/">date-fns</a> +<li>The <a href="https://date-fns.org">date-fns</a> library manipulates timezone-aware timestamps in browsers and in <a href="https://nodejs.org/en/">Node.js</a>. It is freely available under the <abbr>MIT</abbr> license.</li> @@ -552,9 +550,9 @@ objects</a> let programs access an abstract view of <code><abbr>tzdb</abbr></code> data, and are designed to replace <a href="https://codeofmatt.com/javascript-date-type-is-horribly-broken/">JavaScript's problematic <code>Date</code> objects</a> when working with dates and times. -<li><a href="https://github.com/JuliaTime/">JuliaTime</a> contains a +<li><a href="https://github.com/JuliaTime">JuliaTime</a> contains a compiler from <code><abbr>tz</abbr></code> source into -<a href="https://julialang.org/">Julia</a>. It is freely available +<a href="https://julialang.org">Julia</a>. It is freely available under the <abbr>MIT</abbr> license.</li> <li><a href="https://github.com/pavkam/tzdb"><abbr>TZDB</abbr> – <abbr>IANA</abbr> Time Zone Database for Delphi/<abbr @@ -565,7 +563,7 @@ as compiled by <a href="https://en.wikipedia.org/wiki/Delphi_(IDE)">Delphi</a> and <a href="https://en.wikipedia.org/wiki/Free_Pascal"><abbr>FPC</abbr></a>. It is freely available under a <abbr>BSD</abbr>-style license.</li> -<li><a href="http://pytz.sourceforge.net">pytz – World Timezone +<li><a href="https://pythonhosted.org/pytz/">pytz – World Timezone Definitions for Python</a> compiles <code><abbr>tz</abbr></code> source into <a href="https://www.python.org">Python</a>. It is freely available under a <abbr>BSD</abbr>-style license. @@ -621,11 +619,11 @@ License.</li> <a href="https://github.com/nayarsystems/posix_tz_db"><code>posix_tz_db</code> package</a> contains Python code to generate <abbr>CSV</abbr> and <abbr>JSON</abbr> tables that map -<code><abbr>tz</abbr></code> settings to POSIX.1-2017-like approximations. +<code><abbr>tz</abbr></code> settings to proleptic TZ approximations. For example, it maps <code>"Africa/Cairo"</code> to <code>"EET-2EEST,M4.5.5/0,M10.5.4/24"</code>, an approximation valid for Cairo timestamps from 2023 on. -This can help porting to platforms that support only POSIX.1-2017. +This can help porting to platforms that support only proleptic TZ. The package is freely available under the MIT license.</li> <li><a href="https://github.com/derickr/timelib">Timelib</a> is a C library that reads <abbr>TZif</abbr> files and converts @@ -649,7 +647,7 @@ that represent <code><abbr>tzdb</abbr></code> timezones. Python is freely available under the <a href="https://docs.python.org/3/license.html">Python Software Foundation License</a>. -A companion <a id="pypi-tzdata" href="https://pypi.org/">PyPI</a> module +A companion <a id="pypi-tzdata" href="https://pypi.org">PyPI</a> module <a href="https://pypi.org/project/tzdata/"><code>tzdata</code></a> supplies TZif data if the underlying system data cannot be found; it is freely available under the Apache License.</li> @@ -897,9 +895,10 @@ summarizes and cites historical <abbr>DST</abbr> regulations.</dd> href="https://www.ptb.de/cms/en/fachabteilungen/abt4/fb-44/ag-441/realisation-of-legal-time-in-germany.html">Realisation of Legal Time in Germany</a>.</dd> <dt>Israel</dt> -<dd>The Interior Ministry periodically issues <a -href="ftp://ftp.cs.huji.ac.il/pub/tz/announcements" -hreflang="he">announcements (in Hebrew)</a>.</dd> +<dd><a +href="https://tz.cs.huji.ac.il">Israel Timezone Files</a> +lists official time-change announcements and laws since 1940, +almost all in Hebrew.</dd> <dt>Malaysia</dt> <dd>See Singapore <a href="#Singapore">below</a>.</dd> <dt>Mexico</dt> @@ -1081,6 +1080,20 @@ In practice the two configurations also agree for timestamps before 1972 even though the historical situation is messy, partly because neither <abbr>UTC</abbr> nor <abbr>TAI</abbr> is well-defined for sufficiently old timestamps.</li> +<li><a href="https://kb.meinbergglobal.com/kb/time_sync/ntp/configuration/ntp_leap_second_file">The +<abbr>NTP</abbr> Leap Second File</a> covers the text file +<code>leap-seconds.list</code>, which lists the currently known leap seconds. +The <abbr>IERS</abbr> maintains this file, and a copy is distributed by +<code><abbr>tzdb</abbr></code> for use by <abbr>NTP</abbr> implementations like +<a href="https://www.ntp.org">classic +<code><abbr title="Network Time Protocol Daemon">ntpd</abbr></code></a> +and <a href="https://ntpsec.org">NTPsec</a>. +The <code><abbr>tz</abbr></code> database also distributes leap second +information in a differently-formatted <code>leapseconds</code> text file, +as well as in the "<code>right</code>" configuration in binary form; for +example, <code>right/UTC</code> can be used +by <a href="https://chrony-project.org"><code>chrony</code></a>, +another <abbr>NTP</abbr> implementation.</li> <li><a href="https://developers.google.com/time/smear">Leap Smear</a> discusses how to gradually adjust <abbr>POSIX</abbr> clocks near a leap second so that they disagree with <abbr>UTC</abbr> by at most a @@ -1088,7 +1101,7 @@ half second, even though every <abbr>POSIX</abbr> minute has exactly sixty seconds. This approach works with the default <code><abbr>tz</abbr></code> "<code>posix</code>" configuration, is <a href="http://bk1.ntp.org/ntp-stable/README.leapsmear">supported</a> by -the <abbr>NTP</abbr> reference implementation, <a +the abovementioned <abbr>NTP</abbr> implementations, <a href="https://github.com/google/unsmear">supports</a> conversion between <abbr>UTC</abbr> and smeared <abbr>POSIX</abbr> timestamps, and is used by major cloud service providers. However, according to @@ -1111,11 +1124,18 @@ without Leap Seconds</a> gives pointers on this contentious issue. The General Conference on Weights and Measures <a href="https://www.bipm.org/en/cgpm-2022/resolution-4">decided in 2022</a> -to discontinue the use of leap seconds by 2035, replacing them with an -as-yet-undetermined scheme some time after the year 2135. +to discontinue the use of leap seconds by 2035, and requested that no +discontinuous adjustments be made to UTC for at least a century. The World Radiocommunication Conference <a href="https://www.itu.int/dms_pub/itu-r/opb/act/R-ACT-WRC.15-2023-PDF-E.pdf">resolved in 2023</a> to cooperate with this process. +<a href="https://www.preprints.org/manuscript/202406.0043/v1">A proposal +to change the leap-second adjustments to Coordinated Universal Time</a> +(doi:<a href="https://doi.org/10.1088/1681-7575/ad6266">10.1088/1681-7575/ad6266</a>) +would replace leap seconds with 13-second leap smears occurring once per +decade until 2100, with leap smears after that gradually increasing in size. +However, there is still no consensus on whether this is the best way +to replace leap seconds. </li> </ul> </section> @@ -1153,9 +1173,12 @@ headers.</li> <li> <a href="https://datatracker.ietf.org/doc/html/rfc3339">Date and Time on the Internet: Timestamps</a> (Internet <abbr>RFC</abbr> 3339) -specifies an <abbr>ISO</abbr> 8601 -profile for use in new Internet -protocols.</li> +specifies an <abbr>ISO</abbr> 8601 profile for use in new Internet protocols. +An extension, <a href="https://datatracker.ietf.org/doc/html/rfc9557">Date +and Time on the Internet: Timestamps with Additional Information</a> +(Internet <abbr>RFC</abbr> 9557) extends this profile +to let you specify the <code><abbr>tzdb</abbr></code> timezone of a timestamp +via suffixes like "<code>[Asia/Tokyo]</code>". <li> <a href="https://web.archive.org/web/20190130042457/https://www.hackcraft.net/web/datetime/">Date & Time Formats on the Web</a> surveys web- and Internet-oriented date and time @@ -1173,8 +1196,8 @@ unfortunately some of these abbreviations were merely the database maintainers' inventions, and these have been removed when possible.</li> <li>Numeric time zone abbreviations typically count hours east of <abbr>UT</abbr>, e.g., +09 for Japan and -−10 for Hawaii. However, the <abbr>POSIX</abbr> -<code><abbr>TZ</abbr></code> environment variable uses the opposite convention. +−10 for Hawaii. However, <abbr>POSIX</abbr> proleptic +<code><abbr>TZ</abbr></code> settings use the opposite convention. For example, one might use <code><abbr>TZ</abbr>="<abbr title="Japan Standard Time">JST</abbr>-9"</code> and <code><abbr>TZ</abbr>="<abbr title="Hawaii Standard Time">HST</abbr>10"</code> |