2002-01-29 15:30:41 +03:00
|
|
|
<?xml version="1.0" encoding="US-ASCII"?>
|
|
|
|
|
<!DOCTYPE html
|
|
|
|
|
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
|
|
|
|
|
"DTD/xhtml1-strict.dtd">
|
|
|
|
|
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
|
|
|
|
|
<head>
|
|
|
|
|
<title>Sources for Time Zone and Daylight Saving Time Data</title>
|
|
|
|
|
<link rel="schema.DC" href="http://purl.org/DC/elements/1.1/" />
|
|
|
|
|
<meta http-equiv="Content-type" content='text/html; charset="US-ASCII"' />
|
|
|
|
|
<meta name="DC.Creator" content="Eggert, Paul" />
|
|
|
|
|
<meta name="DC.Contributor" content="Olson, Arthur David" />
|
|
|
|
|
<meta name="DC.Date" content="2001-05-30" />
|
|
|
|
|
<meta name="DC.Description"
|
|
|
|
|
content="Sources of information about time zones and daylight saving time" />
|
|
|
|
|
<meta name="DC.Identifier" content="http://www.twinsun.com/tz/tz-link.htm" />
|
|
|
|
|
<meta name="Keywords"
|
|
|
|
|
content="database,daylight saving,DST,time zone,timezone,tz,zoneinfo" />
|
|
|
|
|
</head>
|
|
|
|
|
<body>
|
|
|
|
|
<h1>Sources for Time Zone and Daylight Saving Time Data</h1>
|
|
|
|
|
<address>
|
|
|
|
|
@(#)tz-link.htm 7.34
|
|
|
|
|
</address>
|
|
|
|
|
<p>
|
2000-12-12 18:21:09 +03:00
|
|
|
Please send corrections to this web page to the
|
2002-01-29 15:30:41 +03:00
|
|
|
<a href="mailto:tz@elsie.nci.nih.gov">time zone mailing list</a>.
|
|
|
|
|
</p>
|
|
|
|
|
<h2>The <code>tz</code> database</h2>
|
|
|
|
|
<p>
|
2000-12-12 18:21:09 +03:00
|
|
|
The public-domain time zone database contains code and data
|
|
|
|
|
that represent the history of local time
|
|
|
|
|
for many representative locations around the globe.
|
|
|
|
|
It is updated periodically to reflect changes made by political bodies
|
|
|
|
|
to UTC offsets and daylight-saving rules.
|
2002-01-29 15:30:41 +03:00
|
|
|
This database (often called <code>tz</code> or <code>zoneinfo</code>)
|
2000-12-12 18:21:09 +03:00
|
|
|
is used by several implementations,
|
2002-01-29 15:30:41 +03:00
|
|
|
including
|
|
|
|
|
<a href="http://www.linux.org/">GNU/Linux</a>,
|
|
|
|
|
<a href="http://www.freebsd.org/">FreeBSD</a>,
|
|
|
|
|
<a href="http://www.netbsd.org/">NetBSD</a>,
|
|
|
|
|
<a href="http://www.openbsd.org/">OpenBSD</a>,
|
|
|
|
|
<a href="http://www.delorie.com/djgpp/">DJGPP</a>,
|
|
|
|
|
<a href="http://www.hp.com/products1/unix/operating/index.html">HP-UX</a>,
|
|
|
|
|
<a href="http://www.sgi.com/developers/technology/irix.html">IRIX</a>,
|
|
|
|
|
<a href="http://www.caldera.com/products/openunix/">Open UNIX</a>,
|
|
|
|
|
<a href="http://www.sun.com/solaris/">Solaris</a>, and
|
|
|
|
|
<a href="http://www.tru64unix.compaq.com/">Tru64</a>.</p>
|
|
|
|
|
<p>
|
|
|
|
|
Each location in the database represents a national region where all
|
|
|
|
|
clocks keeping local time have agreed since 1970.
|
|
|
|
|
Locations are identified by continent or ocean and then by the name of
|
|
|
|
|
the location, which is typically the largest city within the region.
|
|
|
|
|
For example, <code>America/New_York</code>
|
|
|
|
|
represents most of the US eastern time zone;
|
|
|
|
|
<code>America/Indianapolis</code> represents most of Indiana, which
|
|
|
|
|
uses eastern time without daylight saving time (DST);
|
|
|
|
|
<code>America/Detroit</code> represents most of Michigan, which uses
|
|
|
|
|
eastern time but with different DST rules in 1975;
|
|
|
|
|
and other entries represent smaller regions like Starke County,
|
|
|
|
|
Kentucky, which switched from central to eastern time in 1991.
|
|
|
|
|
To use the database, set the <code>TZ</code> environment variable to
|
|
|
|
|
the location's full name, e.g., <code>TZ="America/New_York"</code>.</p>
|
|
|
|
|
<p>
|
|
|
|
|
In the <code>tz</code> database's
|
|
|
|
|
<a href="ftp://elsie.nci.nih.gov/pub/">FTP distribution</a>,
|
|
|
|
|
the code is in the file <code>tzcode<var>C</var>.tar.gz</code>,
|
|
|
|
|
where <code><var>C</var></code> is the code's version;
|
|
|
|
|
similarly, the data are in <code>tzdata<var>D</var>.tar.gz</code>,
|
|
|
|
|
where <code><var>D</var></code> is the data's version.
|
|
|
|
|
The following shell commands download
|
|
|
|
|
these files to a GNU/Linux or similar host; see the downloaded
|
|
|
|
|
<code>README</code> file for what to do next.</p>
|
|
|
|
|
<pre style="margin-left: 2em"><code><a href="http://www.gnu.org/software/wget/">wget</a> 'ftp://elsie.nci.nih.gov/pub/tz*.tar.gz'
|
|
|
|
|
<a href="http://www.gnu.org/software/gzip/">gzip</a> -dc tzcode*.tar.gz | <a href="http://www.gnu.org/software/tar/">tar</a> -xf -
|
|
|
|
|
gzip -dc tzdata*.tar.gz | tar -xf -
|
|
|
|
|
</code></pre>
|
|
|
|
|
<p>
|
|
|
|
|
The code lets you compile the <code>tz</code> source files into
|
|
|
|
|
machine-readable binary files, one for each location. It also lets
|
|
|
|
|
you read a <code>tz</code> binary file and interpret time stamps for that
|
|
|
|
|
location.</p>
|
|
|
|
|
<p>
|
2000-12-12 18:21:09 +03:00
|
|
|
The data are by no means authoritative. If you find errors, please
|
2002-01-29 15:30:41 +03:00
|
|
|
send changes to the <a href="mailto:tz@elsie.nci.nih.gov">time zone
|
|
|
|
|
mailing list</a>. You can also <a
|
|
|
|
|
href="mailto:tz-request@elsie.nci.nih.gov">subscribe</a> to the
|
|
|
|
|
mailing list, or retrieve the <a
|
|
|
|
|
href="ftp://elsie.nci.nih.gov/pub/tzarchive.gz">archive of old
|
|
|
|
|
messages</a> (in gzip compressed format).</p>
|
|
|
|
|
<p>
|
2000-12-12 18:21:09 +03:00
|
|
|
The Web has several other sources for time zone and daylight saving time data.
|
|
|
|
|
Here are some recent links that may be of interest.
|
2002-01-29 15:30:41 +03:00
|
|
|
</p>
|
|
|
|
|
<h2>Web pages using recent versions of the <code>tz</code> database</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a href="http://www.bsdi.com/date/">Date and Time Gateway</a> is a
|
2000-12-12 18:21:09 +03:00
|
|
|
text-based point-and-click interface to tables of current time
|
2002-01-29 15:30:41 +03:00
|
|
|
throughout the world.</li>
|
|
|
|
|
<li><a href="http://sandbox.xerox.com/stewart/tzconvert.cgi">Timezone
|
|
|
|
|
Converter</a> is a similar interface, with source code
|
|
|
|
|
written in <a href="http://www.perl.org/">Perl</a>, using what Paul
|
|
|
|
|
Stewart calls the "20-line hack no one will let me forget".</li>
|
|
|
|
|
<li>Fancier web interfaces, roughly in ascending order of complexity, include:
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a href="http://www.hilink.com.au/times/">Local Times Around the
|
|
|
|
|
World</a></li>
|
|
|
|
|
<li><a href="http://www.convertit.com/Go/ConvertIt/World_Time/Current_Time.ASP">Current Time in 1000 Places</a></li>
|
|
|
|
|
<li><a href="http://timezoneconverter.com/">Time Zone Converter</a></li>
|
|
|
|
|
</ul></li>
|
|
|
|
|
<li><a href="http://www.tick2tock.com/cgi-bin/TZConverter">Tick2Tock
|
|
|
|
|
time zone converter</a> is a multilingual interface.</li>
|
|
|
|
|
<li><a href="http://www.holidayfestival.com/">The Worldwide Holiday
|
|
|
|
|
& Festival Site</a> lists DST-related clock changes along with
|
|
|
|
|
holidays.</li>
|
|
|
|
|
<li><a href="http://www.timeanddate.com/worldclock/">The World Clock</a>
|
2000-12-12 18:21:09 +03:00
|
|
|
is a web interface to a time zone database derived from
|
2002-01-29 15:30:41 +03:00
|
|
|
<code>tz</code>'s.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Other <code>tz</code> compilers</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a href="http://primates.ximian.com/~damon/icalendar/">Olson ->
|
|
|
|
|
VTIMEZONE Converter</a> describes a program Vzic that
|
|
|
|
|
compiles <code>tz</code> source into VTIMEZONE text as specified by
|
|
|
|
|
the <a href="ftp://ftp.isi.edu/in-notes/rfc2445.txt">iCalendar</a>
|
|
|
|
|
specification published by the <a
|
|
|
|
|
href="http://www.ietf.org/html.charters/calsch-charter.html">IETF
|
|
|
|
|
Calendaring and Scheduling Working Group</a>. Vzic is freely
|
|
|
|
|
available under the <a href="http://www.gnu.org/copyleft/gpl.html">GNU
|
|
|
|
|
General Public License (GPL)</a>.</li>
|
|
|
|
|
<li>Possible XML schemata for the <code>tz</code> data include <a
|
|
|
|
|
href="http://www.w3.org/2000/01/foo">one</a> sketched out by <a
|
|
|
|
|
href="http://www.w3.org/People/Berners-Lee/">Tim Berners-Lee</a> and
|
|
|
|
|
<a
|
|
|
|
|
href="http://developer.iplanet.com/docs/wpapers/calendar/ietf.txt">another</a>
|
|
|
|
|
used by the <a
|
|
|
|
|
href="http://www.iplanet.com/products/iplanet_calendar/">iPlanet
|
|
|
|
|
Calendar Server</a>.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Other <code>tz</code> binary file readers</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li>The <a href="http://www.gnu.org/software/libc/">GNU C Library</a>
|
2000-12-12 18:21:09 +03:00
|
|
|
has an independent, thread-safe implementation of
|
2002-01-29 15:30:41 +03:00
|
|
|
a <code>tz</code> binary file reader.
|
2000-12-12 18:21:09 +03:00
|
|
|
This library is freely available under the
|
2002-01-29 15:30:41 +03:00
|
|
|
<a href="http://www.gnu.org/copyleft/lesser.html">
|
|
|
|
|
GNU Lesser General Public License (LGPL)</a>,
|
|
|
|
|
and is widely used in GNU/Linux systems.</li>
|
|
|
|
|
<li><a href="http://www.bmsi.com/java/#TZ">ZoneInfo.java</a>
|
|
|
|
|
is a <code>tz</code> binary file reader written in Java.
|
|
|
|
|
It is freely available under the GNU LGPL.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Other <code>tz</code>-based time zone conversion software</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a
|
|
|
|
|
href="http://www1.tip.nl/~t876506/AboutTimeZonesHC.html">HyperCard
|
|
|
|
|
time zones calculator</a> is a HyperCard stack.</li>
|
|
|
|
|
<li><a
|
|
|
|
|
href="http://www20.Brinkster.com/timezone50/">Time Zone Converter</a> is a
|
|
|
|
|
Microsoft Windows program.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Other time zone databases</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a href="http://www.astro.ch/cgi-bin/atlw3/aq.cgi?lang=e">Astrodienst
|
|
|
|
|
- Atlas Query</a> is Astrodienst's Web version of Shanks's
|
|
|
|
|
excellent time zone history atlases published in both <a
|
|
|
|
|
href="http://astrocom.com/software/pcatlas.html">computer</a> and <a
|
|
|
|
|
href="http://astrocom.com/books/xrefa.htm#SHANKS">book</a> form by <a
|
|
|
|
|
href="http://astrocom.com/">Astro Communications Services</a>.</li>
|
|
|
|
|
<li><a href="http://worldtime.com/">WORLDTIME: interactive atlas,
|
|
|
|
|
time info, public holidays</a>
|
2000-12-12 18:21:09 +03:00
|
|
|
contains information on local time, sunrise and sunset,
|
2002-01-29 15:30:41 +03:00
|
|
|
and public holidays in several hundred cities around the world.</li>
|
|
|
|
|
<li><a href="http://www.worldtimeserver.com/">World Time Server</a>
|
|
|
|
|
is another time zone database.</li>
|
|
|
|
|
<li><a href="http://tycho.usno.navy.mil/tzones.html">World Time Zones</a>
|
2000-12-12 18:21:09 +03:00
|
|
|
contains data from the Time Service Department of the US Naval Observatory
|
|
|
|
|
(USNO), used as the source
|
2002-01-29 15:30:41 +03:00
|
|
|
for the <code>usno*</code> files in the <code>tz</code> distribution.</li>
|
|
|
|
|
<li><a href="http://www.airportcitycodes.com/aaa/">Airlines, Airplanes
|
|
|
|
|
and Airports</a> lists current standard times for thousands of
|
|
|
|
|
airports around the world. This seems to be derived from
|
|
|
|
|
the <a href="http://www.iata.org/sked/ssim.htm">Standard
|
|
|
|
|
Schedules Information Manual</a> of the
|
|
|
|
|
the <a href="http://www.iata.org/">International Air Transport
|
|
|
|
|
Association</a>,
|
2000-12-12 18:21:09 +03:00
|
|
|
which gives current time zone rules for
|
2002-01-29 15:30:41 +03:00
|
|
|
all the airports served by commercial aviation.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Maps</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li>The <a href="http://www.odci.gov/">United States Central
|
|
|
|
|
Intelligence Agency (CIA)</a> publishes a <a
|
|
|
|
|
href="http://www.odci.gov/cia/publications/factbook/ref/pdf/802801.pdf">time
|
|
|
|
|
zone map</a>; the
|
|
|
|
|
<a
|
|
|
|
|
href="http://www.lib.utexas.edu/maps/world.html">Perry-Castañeda
|
|
|
|
|
Library Map Collection</a>
|
|
|
|
|
of the University of Texas at Austin has copies of
|
|
|
|
|
recent editions.
|
2000-12-12 18:21:09 +03:00
|
|
|
The pictorial quality is good,
|
|
|
|
|
but the maps do not indicate summer time,
|
2002-01-29 15:30:41 +03:00
|
|
|
and parts of the data are a few years out of date.</li>
|
|
|
|
|
<li><a href="http://wwg.lgg.ru/russia/timezone.html"
|
|
|
|
|
hreflang="ru">Map of Russian Federation time zones (in Russian)</a>
|
|
|
|
|
has a wealth of information about Russian time zones.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Time zone boundaries</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li>Manifold.net's <a
|
|
|
|
|
href="http://www.manifold.net/download/freemaps.html">Free Maps and
|
|
|
|
|
GIS Data</a> includes a Manifold-format map of world time zone
|
|
|
|
|
boundaries distributed under the GPL. The GeoCommunity's <a
|
|
|
|
|
href="http://software.geocomm.com/data/intl_timezones.html">International
|
|
|
|
|
Time Zones</a> publishes the same data in other formats.</li>
|
|
|
|
|
<li>The US Geological Survey's National Atlas of the United States
|
|
|
|
|
publishes the <a href="http://www.nationalatlas.gov/timeznm.html">Time
|
|
|
|
|
Zones of the United States</a> in the public domain.</li>
|
|
|
|
|
<li>The National Weather Service publishes <a
|
|
|
|
|
href="http://isl715.nws.noaa.gov/mapdata/newcat/county/county_all.htm">outlines
|
|
|
|
|
of US counties and their time zones</a> in the public domain.</li>
|
|
|
|
|
<li>The GeoCommunity lists several commercial sources for <a
|
|
|
|
|
href="http://spatialnews.geocomm.com/features/timezones/">International
|
|
|
|
|
Time Zones and Time Zone Data</a>.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Daylight saving time concepts and history</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a href="http://webexhibits.com/daylightsaving/">About Daylight
|
|
|
|
|
Saving Time - History, rationale, laws and dates</a>
|
|
|
|
|
is a good overall history of DST.</li>
|
|
|
|
|
<li><a href="http://toi.iriti.cnr.it/">The
|
|
|
|
|
Time of Internet</a>
|
2000-12-12 18:21:09 +03:00
|
|
|
contains good descriptions of Time Zones and daylight saving time,
|
|
|
|
|
with diagrams.
|
2002-01-29 15:30:41 +03:00
|
|
|
The time zone map is out of date, however.</li>
|
|
|
|
|
<li><a href="http://www.phys.uu.nl/~vgent/idl/idl.htm">A History of
|
|
|
|
|
the International Date Line</a> tells the story of the most important
|
|
|
|
|
time zone boundary.</li>
|
|
|
|
|
<li>A few countries have well-documented histories of legal time.
|
|
|
|
|
<dl>
|
|
|
|
|
<dt>Australia</dt>
|
|
|
|
|
<dd><a
|
|
|
|
|
href="http://www.dstc.qut.edu.au/DST/marg/daylight.html#more">Australia's
|
|
|
|
|
Daylight Saving Times</a> contains pointers to government records and to
|
|
|
|
|
histories of daylight saving.</dd>
|
|
|
|
|
<dt>Belgium</dt>
|
|
|
|
|
<dd>The Royal Observatory of Belgium maintains a table of <a
|
|
|
|
|
href="http://www.astro.oma.be/GENERAL/INFO/nli001a.html"
|
|
|
|
|
hreflang="nl">time in Belgium (in Dutch)</a>.</dd>
|
|
|
|
|
<dt>Brazil</dt>
|
|
|
|
|
<dd>The Time Service Department of the National Observatory
|
|
|
|
|
records <a href="http://pcdsh01.on.br/DecHV.html"
|
|
|
|
|
hreflang="pt-BR">Brazil's daylight saving time decrees (in
|
|
|
|
|
Portuguese)</a>.</dd>
|
|
|
|
|
<dt>Canada</dt>
|
|
|
|
|
<dd>The Institute for National Measurement Standards publishes current
|
|
|
|
|
and some older information about <a
|
|
|
|
|
href="http://www.nrc.ca/inms/time/tze.html">Time Zones and Daylight
|
|
|
|
|
Saving Time</a>.</dd>
|
|
|
|
|
<dt>Germany</dt>
|
|
|
|
|
<dd>The National Institute for Science and Technology maintains the <a
|
|
|
|
|
href="http://www.ptb.de/en/org/4/43/432/lega.htm">Realisation of
|
|
|
|
|
Legal Time in Germany</a>.</dd>
|
|
|
|
|
<dt>Israel</dt>
|
|
|
|
|
<dd>The Ministry of Interior periodically issues <a
|
|
|
|
|
href="ftp://ftp.huji.ac.il/pub/tz/announcements"
|
|
|
|
|
hreflang="he">announcements (in Hebrew)</a>.</dd>
|
|
|
|
|
<dt>Mexico</dt>
|
|
|
|
|
<dd>The Investigation and Analysis Service of the Mexican Library of
|
|
|
|
|
Congress has published a <a
|
|
|
|
|
href="http://www.cddhcu.gob.mx/bibliot/publica/inveyana/polisoc/horver/"
|
|
|
|
|
hreflang="es">history of Mexican local time (in Spanish)</a>.</dd>
|
|
|
|
|
<dt>Netherlands</dt>
|
|
|
|
|
<dd><a href="http://www.phys.uu.nl/~vgent/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>United Kingdom</dt>
|
|
|
|
|
<dd><a
|
|
|
|
|
href="http://student.cusu.cam.ac.uk/~jsm28/british-time/">History of
|
|
|
|
|
legal time in Britain</a> is an excellent discussion for the country
|
2000-12-12 18:21:09 +03:00
|
|
|
with perhaps the best-documented history of clock adjustments.
|
2002-01-29 15:30:41 +03:00
|
|
|
The National Physical Laboratory also maintains an <a
|
|
|
|
|
href="http://www.npl.co.uk/npl/ctm/summer_time_archive.html">archive
|
|
|
|
|
of summer time dates</a>.</dd>
|
|
|
|
|
</dl></li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Precision timekeeping</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a
|
|
|
|
|
href="http://literature.agilent.com/litwebbin/purl.cgi?org_id=tmo&pub_id=5965-7984E">The
|
|
|
|
|
Science of Timekeeping</a> is an excellent and thorough introduction
|
|
|
|
|
to the theory and practice of precision timekeeping.</li>
|
|
|
|
|
<li><a href="http://www.ntp.org/">Time Server</a> discusses
|
|
|
|
|
the Network Time Protocol (NTP), used to synchronize clocks of
|
|
|
|
|
Internet hosts.</li>
|
|
|
|
|
<li><a href="http://ecco.bsee.swin.edu.au/chronos/GMT-explained.html">A
|
|
|
|
|
Few Facts Concerning GMT, UT, and the RGO</a>
|
|
|
|
|
answers questions like "What is the difference between GMT and UTC?"</li>
|
|
|
|
|
<li><a
|
|
|
|
|
href="http://sadira.gb.nrao.edu/~rfisher/Ephemerides/times.html">Astronomical
|
|
|
|
|
Times</a> explains more abstruse astronomical time scales like TT, TCG,
|
|
|
|
|
and TDB.</li>
|
|
|
|
|
<li>The <a href="http://www.iau.org/">IAU</a>'s <a
|
|
|
|
|
href="http://www.iau-sofa.rl.ac.uk/">Standards Of Fundamental
|
|
|
|
|
Astronomy</a> (SOFA) initiative publishes Fortran code for converting
|
|
|
|
|
among time scales like TAI, TDB, TT and UTC.</li>
|
|
|
|
|
<li><a href="http://www.jpl.nasa.gov/basics/bsf2-3.htm">Basics of
|
|
|
|
|
Space Flight - Reference Systems - Time Conventions</a>
|
|
|
|
|
briefly explains interplanetary space flight timekeeping.</li>
|
|
|
|
|
<li><a
|
|
|
|
|
href="http://hpiers.obspm.fr/eop-pc/products/bulletins.html">Bulletins
|
|
|
|
|
maintained by the IERS EOP (PC)</a> contains official publications of
|
|
|
|
|
the Earth Orientation Parameters Product Center of the
|
2000-12-12 18:21:09 +03:00
|
|
|
International Earth Rotation Service, the committee that decides
|
2002-01-29 15:30:41 +03:00
|
|
|
when leap seconds occur.</li>
|
|
|
|
|
<li>The <a
|
|
|
|
|
href="http://clockdev.usno.navy.mil/archives/leapsecs.html">Leap
|
|
|
|
|
Second Discussion List</a> covers <a
|
|
|
|
|
href="http://clockdev.usno.navy.mil/cgi-bin/wa.exe?A3=ind00&L=leapsecs&P=28537&E=2&B=------_=_NextPart_000_01C0781C.F015C5B0&N=GPS-Nov99_Innov.pdf&T=application/octet-stream">McCarthy
|
|
|
|
|
and Klepczynski's proposal to discontinue leap seconds</a>
|
|
|
|
|
(which requires discussion list membership to read).
|
|
|
|
|
This proposal is being studied by the URSI Commission J <a
|
|
|
|
|
href="http://space.mit.edu/URSI/leapsecond.html">Working Group on the
|
|
|
|
|
Leap Second</a>, and the IAU
|
|
|
|
|
has plans to report on this proposal by 2003.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Time notation</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li>
|
|
|
|
|
<a href="http://www.cl.cam.ac.uk/~mgk25/iso-time.html">A Summary of
|
|
|
|
|
the International Standard Date and Time Notation</a> is a good
|
|
|
|
|
summary of ISO
|
|
|
|
|
8601:1988 - Data elements and interchange formats - Information interchange
|
|
|
|
|
- Representation of dates and times (which has been superseded by
|
|
|
|
|
<a href="http://www.iso.ch/cate/d26780.html">ISO 8601:2000</a>).</li>
|
|
|
|
|
<li>
|
|
|
|
|
Section 3.3 of <a
|
|
|
|
|
href="ftp://ftp.isi.edu/in-notes/rfc2822.txt">Internet RFC 2822</a>
|
|
|
|
|
specifies the time notation used in email and <a
|
|
|
|
|
href="ftp://ftp.isi.edu/in-notes/rfc2616.txt">HTTP</a> headers.</li>
|
|
|
|
|
<li>
|
|
|
|
|
<a
|
|
|
|
|
href="ftp://ftp.isi.edu/internet-drafts/draft-ietf-impp-datetime-05.txt">Date
|
|
|
|
|
and Time on the Internet: Timestamps</a> proposes an ISO 8601 profile
|
|
|
|
|
for use in new Internet protocols.</li>
|
|
|
|
|
<li>
|
|
|
|
|
Alphabetic time zone abbreviations should not be used as unique
|
|
|
|
|
identifiers for UTC offsets as they are ambiguous in practice. For
|
|
|
|
|
example, "EST" denotes 5 hours behind UTC in English-speaking North
|
|
|
|
|
America, but it denotes 10 or 11 hours ahead of UTC in Australia;
|
|
|
|
|
and French-speaking North Americans prefer "HNE" to "EST". For
|
|
|
|
|
compatibility with <a href="http://www.pasc.org/#POSIX">POSIX</a> the
|
|
|
|
|
<code>tz</code> database contains English abbreviations for all time
|
|
|
|
|
stamps but in many cases these are merely inventions of the database
|
|
|
|
|
maintainers.</li>
|
|
|
|
|
</ul>
|
|
|
|
|
<h2>Related indexes</h2>
|
|
|
|
|
<ul>
|
|
|
|
|
<li><a href="http://dmoz.org/Reference/Time/">Open Directory -
|
|
|
|
|
Reference: Time</a></li>
|
|
|
|
|
<li><a href="tz-art.htm">Time and the Arts</a></li>
|
|
|
|
|
<li><a href="http://dir.yahoo.com/Science/Measurements_and_Units/Time/Time_Zones/">Yahoo! - Science:Measurements and Units:Time:Time Zones</a></li>
|
|
|
|
|
</ul>
|
|
|
|
|
</body>
|
|
|
|
|
</html>
|
