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Diffstat (limited to 'elsie.nci.nih.gov/src/tz-link.htm')
| -rw-r--r-- | elsie.nci.nih.gov/src/tz-link.htm | 154 |
1 files changed, 83 insertions, 71 deletions
diff --git a/elsie.nci.nih.gov/src/tz-link.htm b/elsie.nci.nih.gov/src/tz-link.htm index 98594f4..444ef94 100644 --- a/elsie.nci.nih.gov/src/tz-link.htm +++ b/elsie.nci.nih.gov/src/tz-link.htm @@ -8,7 +8,7 @@ <meta http-equiv="Content-type" content='text/html; charset="UTF-8"'> <meta name="DC.Creator" content="Eggert, Paul"> <meta name="DC.Contributor" content="Olson, Arthur David"> -<meta name="DC.Date" content="2014-10-21"> +<meta name="DC.Date" content="2014-11-09"> <meta name="DC.Description" content="Sources of information about time zones and daylight saving time"> <meta name="DC.Identifier" @@ -26,10 +26,8 @@ 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 <a href="http://en.wikipedia.org/wiki/Time_zone">time zone</a> -boundaries, <a -href="http://en.wikipedia.org/wiki/Coordinated_Universal_Time"><abbr -title="Coordinated Universal Time">UTC</abbr></a> offsets, and -<a href="http://en.wikipedia.org/wiki/Daylight_saving">daylight-saving</a> +boundaries and +<a href="http://en.wikipedia.org/wiki/Daylight_saving_time">daylight-saving</a> rules. This database (often called <code>zoneinfo</code> or <code><abbr>tz</abbr></code>) @@ -38,15 +36,15 @@ including <a href="http://www.gnu.org/software/libc/">the <abbr title="GNU's Not Unix">GNU</abbr> C Library</a> (used in -<a href="http://www.linux.org/"><abbr>GNU</abbr>/Linux</a>), -<a href="http://www.android.com/">Android</a>, -<a href="https://developer.mozilla.org/en-US/docs/Mozilla/Firefox_OS">Firefox +<a href="http://en.wikipedia.org/wiki/Linux"><abbr>GNU</abbr>/Linux</a>), +<a href="http://www.android.com">Android</a>, +<a href="https://developer.mozilla.org/en-US/Firefox_OS">Firefox <abbr title="Operating System">OS</abbr></a>, -<a href="http://www.freebsd.org/">Free<abbr +<a href="https://www.freebsd.org">Free<abbr title="Berkeley Software Distribution">BSD</abbr></a>, -<a href="http://netbsd.org/">Net<abbr>BSD</abbr></a>, -<a href="http://openbsd.org/">Open<abbr>BSD</abbr></a>, -<a href="http://cygwin.com/">Cygwin</a>, +<a href="http://netbsd.org">Net<abbr>BSD</abbr></a>, +<a href="http://openbsd.org">Open<abbr>BSD</abbr></a>, +<a href="https://cygwin.com">Cygwin</a>, <a href="http://www.delorie.com/djgpp/"><abbr title="DJ's GNU Programming Platform">DJGPP</abbr></a>, <a href="http://en.wikipedia.org/wiki/Symbian">Symbian</a>, @@ -57,15 +55,15 @@ title="Advanced Interactive eXecutive">AIX</abbr></a>, <a href="http://en.wikipedia.org/wiki/BlackBerry_10">BlackBerry 10</a>, <a href="http://www.apple.com/ios/"><abbr title="iPhone OS">iOS</abbr></a>, -<a href="http://windows.microsoft.com/">Microsoft Windows</a>, -<a href="http://h71000.www7.hp.com/">Open<abbr +<a href="http://windows.microsoft.com">Microsoft Windows</a>, +<a href="http://h71000.www7.hp.com">Open<abbr title="Virtual Memory System">VMS</abbr></a>, -<a href="http://oracle.com/database">Oracle Database</a>, +<a href="https://www.oracle.com/database/index.html">Oracle Database</a>, +<a href="http://oracle.com/solaris">Oracle Solaris</a>, and <a href="http://www.apple.com/osx/"><abbr title="Operating System Ten">OS -X</abbr></a>, and -<a href="http://oracle.com/solaris">Solaris</a>.</p> +X</abbr></a>.</p> <p> -Each location in the database represents a national region where all +Each location in the database represents a 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. @@ -86,6 +84,18 @@ 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> <p> +Associated with each region is a history of offsets from +<a href="http://en.wikipedia.org/wiki/Universal_Time">Universal +Time</a> (<abbr>UT</abbr>), which is <a +href="http://en.wikipedia.org/wiki/Greenwich_Mean_Time">Greenwich Mean +Time</a> (<abbr>GMT</abbr>) with days beginning at midnight; +for time stamps after 1960 this is more precisely <a +href="http://en.wikipedia.org/wiki/Coordinated_Universal_Time">Coordinated +Universal Time</a> (<abbr>UTC</abbr>). +The database also records when daylight saving time was in use, +along with alphabetic time zone abbreviations such as <abbr>EST</abbr> +for Eastern Standard Time in the <abbr>US</abbr>.</p> +<p> In the <code><abbr>tz</abbr></code> database's <a href="ftp://ftp.iana.org/tz/releases/"><abbr title="File Transfer Protocol">FTP</abbr> releases</a> @@ -120,8 +130,8 @@ of the <a href="http://www.iana.org">Internet Assigned Numbers Authority (IANA)</a>. An <a href="https://github.com/eggert/tz">unofficial development repository</a> of the code and data is available -in <a href="http://git-scm.com/">Git</a> form -from <a href="https://github.com/">GitHub</a>; be careful, as this +in <a href="http://git-scm.com">Git</a> form +from <a href="https://github.com">GitHub</a>; be careful, as this repository is less well tested and probably contains more errors. <p> The code lets you compile the <code><abbr>tz</abbr></code> source files into @@ -163,7 +173,7 @@ database's style.</li> These are listed roughly in ascending order of complexity and fanciness. </p> <ul> -<li><a href="http://time.is/">Time.is</a> shows locations' +<li><a href="http://time.is">Time.is</a> shows locations' time and zones in a simple format.</li> <li><a href="http://twiki.org/cgi-bin/xtra/tzdatepick.html">Date and Time Gateway</a> @@ -178,25 +188,25 @@ uses a pulldown menu.</li> timezone information for all countries</a> displays tables of DST rules. <li><a href="http://timeanddate.com/worldclock/">The World Clock – Time Zones</a> lets you sort zone names and convert times.</li> -<li><a href="http://permatime.com/">Permatime</a> generates and views +<li><a href="http://permatime.com">Permatime</a> generates and views links that refer to a particular point in time and can be displayed in multiple time zones.</li> <li><a href="http://www.zeitverschiebung.net/en/">Time Difference</a> calculates the current time difference between locations.</li> -<li><a href="http://www.wx-now.com/">Weather Now</a> lists the weather too.</li> -<li><a href="http://worldtime.io/">worldtime.io</a> +<li><a href="http://www.wx-now.com">Weather Now</a> lists the weather too.</li> +<li><a href="http://worldtime.io">worldtime.io</a> also contains data about time zone boundaries; it supports queries via place names and shows location maps.</li> </ul> <h2>Network protocols for <code><abbr>tz</abbr></code> data</h2> <ul> -<li>The <a href="http://www.ietf.org/">Internet Engineering Task Force</a>'s -<a href="https://datatracker.ietf.org/wg/tzdist/charter/">Time Zone Data +<li>The <a href="http://www.ietf.org">Internet Engineering Task Force</a>'s +<a href="http://datatracker.ietf.org/wg/tzdist/charter/">Time Zone Data Distribution Service (tzdist) working group</a> is developing a scalable protocol for distributing time zone data to clients. It has generated a a <a href="http://datatracker.ietf.org/doc/draft-ietf-tzdist-service/">draft protocol for transferring time zone data</a> and a <a -href="https://datatracker.ietf.org/doc/draft-ietf-tzdist-caldav-timezone-ref/">draft +href="http://datatracker.ietf.org/doc/draft-ietf-tzdist-caldav-timezone-ref/">draft protocol for transferring time zone data by reference</a>. This work is based on the iCalendar and CalConnect efforts described below.</li> <li>The <a href="http://tools.ietf.org/html/rfc5545"> @@ -211,9 +221,9 @@ variant <a href="http://tools.ietf.org/html/rfc6321">xCal</a> title="Extensible Markup Language">XML</abbr></a> format, and a variant <a href="http://tools.ietf.org/html/rfc7265">jCal</a> (Internet <abbr>RFC</abbr> 7265) -uses <a href="http://www.json.org/"><abbr +uses <a href="http://www.json.org"><abbr title="JavaScript Object Notation">JSON</abbr></a> format. -<a href="http://calconnect.org/">CalConnect, The Calendaring and Scheduling +<a href="http://calconnect.org">CalConnect, The Calendaring and Scheduling Consortium</a> is promoting further work in this area. <a href="http://calconnect.org/publications/icalendartimezoneproblemsandrecommendationsv1.0.pdf">iCalendar TIMEZONE Problems and Recommendations</a> offers guidelines and @@ -256,14 +266,14 @@ and with a <abbr>BSD</abbr>-style license.</li> <li><a href="http://search.cpan.org/dist/DateTime-TimeZone/">DateTime::TimeZone</a> contains a script <code>parse_olson</code> that compiles -<code><abbr>tz</abbr></code> source into <a href="http://www.perl.org/">Perl</a> +<code><abbr>tz</abbr></code> source into <a href="http://www.perl.org">Perl</a> modules. It is part of the Perl <a -href="http://datetime.perl.org/">DateTime Project</a>, which is freely +href="http://datetime.perl.org">DateTime Project</a>, which is freely available under both the <abbr>GPL</abbr> and the Perl Artistic License. DateTime::TimeZone also contains a script <code>tests_from_zdump</code> that generates test cases for each clock transition in the <code><abbr>tz</abbr></code> database.</li> -<li><a href="http://icu-project.org/">International Components for +<li><a href="http://icu-project.org">International Components for Unicode (<abbr>ICU</abbr>)</a> contains C/C++ and <a href="http://en.wikipedia.org/wiki/Java_%28programming_language%29">Java</a> libraries for internationalization that @@ -279,7 +289,7 @@ contains a class <code>org.joda.time.tz.ZoneInfoCompiler</code> that compiles <code><abbr>tz</abbr></code> source into a Joda-specific binary format. Joda Time is freely available under a <abbr>BSD</abbr>-style license.</li> -<li><a href="http://nodatime.org/">Noda Time – Date and time API for +<li><a href="http://nodatime.org">Noda Time – Date and time API for .NET</a> and <a href="http://www.babiej.demon.nl/Tz4Net/main.htm">TZ4Net</a> are similar to Joda Time, but for the .NET framework instead of Java. They are freely available under the @@ -289,7 +299,7 @@ and a <abbr>BSD</abbr>-style license, respectively.</li> compilers and libraries include: <ul> <li><a href="http://momentjs.com/timezone/">Moment Timezone</a> is a -plugin for the <a href="http://momentjs.com/">Moment.js</a> date +plugin for the <a href="http://momentjs.com">Moment.js</a> date manipulation library. It is freely available under the <abbr title="Massachusetts Institute of Technology">MIT</abbr> license.</li> @@ -297,14 +307,14 @@ license.</li> <abbr>API</abbr> is upward compatible with standard JavaScript Dates. It is freely available under the Apache License.</li> <li><a href="https://github.com/sproutsocial/walltime-js">Walltime-js</a> -translates UTC to local time. It is freely available under the <abbr>MIT</abbr> -license.</li> +translates <abbr>UT</abbr> to local time. It is freely available under +the <abbr>MIT</abbr> license.</li> </ul> <li><a href="http://pytz.sourceforge.net">pytz – World Timezone Definitions for Python</a> compiles <code><abbr>tz</abbr></code> source into -<a href="http://python.org/">Python</a>. +<a href="https://www.python.org">Python</a>. It is freely available under a <abbr>BSD</abbr>-style license.</li> -<li><a href="http://tzinfo.github.io/">TZInfo – +<li><a href="http://tzinfo.github.io">TZInfo – Ruby Timezone Library</a> compiles <code><abbr>tz</abbr></code> source into <a href="http://www.ruby-lang.org/en/">Ruby</a>. @@ -316,7 +326,7 @@ library that compiles <code><abbr>tz</abbr></code> source into a time zone repository whose format is either proprietary or an <abbr>XML</abbr>-encoded representation.</li> -<li><a href="http://tcl.tk/">Tcl</a> +<li><a href="http://tcl.tk">Tcl</a> contains a developer-oriented parser that compiles <code><abbr>tz</abbr></code> source into text files, along with a runtime that can read those files. Tcl is freely available under a <abbr>BSD</abbr>-style @@ -334,9 +344,10 @@ This library is freely available under the <abbr>GNU</abbr> Lesser General Public License (<abbr title="Lesser General Public License">LGPL</abbr>)</a>, and is widely used in <abbr>GNU</abbr>/Linux systems.</li> -<li><a href="http://www.gnome.org/">GNOME</a>'s Glib has +<li><a href="http://www.gnome.org">GNOME</a>'s Glib has a <code><abbr>tz</abbr></code> binary file reader written in C that -creates a <code>GTimeZone</code> object representing sets of UTC offsets. +creates a <code>GTimeZone</code> object representing sets +of <abbr>UT</abbr> offsets. It is freely available under the <abbr>LGPL</abbr>.</li> <li><a href="http://bmsi.com/java/#TZ">ZoneInfo.java</a> is a <code><abbr>tz</abbr></code> binary file reader written in Java. @@ -366,17 +377,17 @@ available under a BSD-style license.</li> </ul> <h2>Other <code><abbr>tz</abbr></code>-based time zone software</h2> <ul> -<li><a href="http://foxclocks.org/">FoxClocks</a> -is an extension for <a href="http://google.com/chrome">Google +<li><a href="https://foxclocks.org">FoxClocks</a> +is an extension for <a href="http://google.com/chrome/">Google Chrome</a> and for <a -href="http://developer.mozilla.org/en/docs/Toolkit_API">Mozilla +href="https://developer.mozilla.org/en-US/docs/Mozilla/Tech/Toolkit_API">Mozilla Toolkit</a> applications like <a -href="http://mozilla.com/firefox">Firefox</a> and <a -href="http://mozilla.com/thunderbird">Thunderbird</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 -interface to <a href="http://earth.google.com/">Google Earth</a>. +interface to <a href="http://www.google.com/earth/">Google Earth</a>. It is freely available under the <abbr>GPL</abbr>.</li> -<li><a href="http://golang.org/">Go programming language</a> +<li><a href="http://golang.org">Go programming language</a> implementations contain a copy of a 32-bit subset of a recent <code><abbr>tz</abbr></code> database in a Go-specific format.</li> @@ -398,18 +409,18 @@ the older, proprietary method of Microsoft Windows 2000 and later, which stores time zone data in the <a href="http://en.wikipedia.org/wiki/Windows_Registry">Windows Registry</a>. The <a -href="http://unicode.org/cldr/charts/supplemental/zone_tzid.html">Zone → +href="http://www.unicode.org/cldr/charts/latest/supplemental/zone_tzid.html">Zone → Tzid table</a> or <a href="http://unicode.org/repos/cldr/trunk/common/supplemental/windowsZones.xml"><abbr>XML</abbr> file</a> of the <abbr>CLDR</abbr> data maps proprietary zone IDs to <code><abbr>tz</abbr></code> names. <li><a -href="http://www.oracle.com/us/technologies/java/overview/index.html">Oracle +href="https://www.oracle.com/java/index.html">Oracle Java</a> contains a copy of a subset of a recent <code><abbr>tz</abbr></code> database in a Java-specific format.</li> -<li><a href="http://kimmo.suominen.com/sw/timezone/">Time Zone</a> is -a <a href="http://wordpress.org/">WordPress</a> plugin. It is freely +<li><a href="https://kimmo.suominen.com/sw/timezone/">Time Zone</a> is +a <a href="https://wordpress.org">WordPress</a> plugin. It is freely available under a <abbr>BSD</abbr>-style license.</li> <li><a href="http://www.relativedata.com/time-zone-master">Time Zone Master</a> is a Microsoft Windows clock program that can automatically @@ -432,24 +443,26 @@ href="http://www.astrocom.com/astrology/books/american-atlas">one volume for the <abbr>US</abbr></a>, and <a href="http://www.astrocom.com/astrology/books/international-atlas">one for other locations</a>) by <a -href="http://astrocom.com/">Astro Computing Services</a>.</li> -<li><a href="http://www.hp.com/go/hpux/">HP-UX</a> has a database in +href="http://astrocom.com">Astro Computing Services</a>. +These atlases are extensive but unreliable, as Shanks appears to have +guessed many <abbr>UT</abbr> offsets and transitions. The atlases cite no +sources and do not indicate which entries are guesswork.</li> +<li><a href="http://en.wikipedia.org/wiki/HP-UX">HP-UX</a> has a database in its own <code>tztab</code>(4) format.</li> <li>Microsoft Windows has proprietary data mentioned above.</li> -<li><a href="http://worldtimeserver.com/">World Time Server</a> +<li><a href="http://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> contains data from the Time Service Department of the <abbr>US</abbr> Naval Observatory.</li> <li>The <a href="http://www.iata.org/publications/Pages/ssim.aspx">Standard Schedules Information Manual</a> of the -<a href="http://iata.org/">International Air Transport -Association</a> +International Air Transport Association gives current time zone rules for airports served by commercial aviation.</li> </ul> <h2>Maps</h2> <ul> -<li>The <a href="https://www.cia.gov/">United States Central +<li>The <a href="https://www.cia.gov/index.html">United States Central Intelligence Agency (<abbr title="Central Intelligence Agency">CIA</abbr>)</a> publishes a <a href="https://www.cia.gov/library/publications/the-world-factbook/graphics/ref_maps/physical/pdf/standard_time_zones_of_the_world.pdf">time @@ -462,7 +475,7 @@ recent editions. The pictorial quality is good, but the maps do not indicate summer time, and parts of the data are a few years out of date.</li> -<li><a href="http://worldtimezone.com/">Current time around the world +<li><a href="http://worldtimezone.com">Current time around the world and standard time zones map of the world</a> has several fancy time zone maps; it covers Russia particularly well. The maps' pictorial quality is not quite as good as the @@ -471,7 +484,7 @@ but the maps are more up to date.</li> <li><a href="http://poisson.phc.unipi.it/~maggiolo/index.php/2014/01/how-much-is-time-wrong-around-the-world/">How much is time wrong around the world?</a> maps the difference between mean solar and standard time, highlighting areas such as western China -where the two differ greatly.</li> +where the two differ greatly. It's a bit out of date, unfortunately.</li> </ul> <h2>Time zone boundaries</h2> <ul> @@ -483,7 +496,7 @@ sets of <code><abbr>tz</abbr></code> regions.</li> maps geographical coordinates to a <code><abbr>tz</abbr></code> region. It is written in Go and is freely available under the Apache License.</li> <li><a href="http://derickrethans.nl/what-time-is-it.html">What Time -is It Here?</a> applies <a href="http://www.mongodb.org/">MongoDB</a> +is It Here?</a> applies <a href="http://www.mongodb.org">MongoDB</a> geospatial query operators to shapefiles' data.</li> <li><a href="http://statoids.com/statoids.html">Administrative Divisions of Countries ("Statoids")</a> contains lists of @@ -609,7 +622,7 @@ of Summer time dates</a>.</dd> href="http://literature.agilent.com/litweb/pdf/5965-7984E.pdf">The Science of Timekeeping</a> is a thorough introduction to the theory and practice of precision timekeeping.</li> -<li><a href="http://www.ntp.org/"><abbr +<li><a href="http://www.ntp.org"><abbr title="Network Time Protocol">NTP</abbr>: The Network Time Protocol</a> discusses how to synchronize clocks of @@ -626,9 +639,8 @@ specifies a <a href="http://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol"><abbr>DHCP</abbr></a> option for a server to configure a client's time zone and daylight saving settings automatically.</li> -<li><a href="http://gauss.gge.unb.ca/GMT.UT.and.the.RGO.html">A Few -Facts Concerning <abbr title="Greenwich Mean Time">GMT</abbr>, <abbr -title="Universal Time">UT</abbr>, and +<li><a href="http://gauss.gge.unb.ca/GMT.UT.and.the.RGO.html">A Few Facts +Concerning <abbr>GMT</abbr>, <abbr>UT</abbr>, and the <abbr title="Royal Greenwich Observatory">RGO</abbr></a> answers questions like "What is the difference between <abbr>GMT</abbr> and <abbr>UTC</abbr>?"</li> @@ -640,9 +652,9 @@ Times</a> explains more abstruse astronomical time scales like <abbr title="Barycentric Dynamic Time">TDB</abbr>. <a href="http://www.ucolick.org/~sla/leapsecs/timescales.html">Time Scales</a> goes into more detail, particularly for historical variants.</li> -<li>The <a href="http://iau.org/"><abbr +<li>The <a href="http://iau.org"><abbr title="International Astronomical Union">IAU</abbr></a>'s <a -href="http://www.iausofa.org/"><abbr +href="http://www.iausofa.org"><abbr title="Standards Of Fundamental Astronomy">SOFA</abbr></a> collection contains C and <a href="http://en.wikipedia.org/wiki/Fortran">Fortran</a> @@ -660,7 +672,7 @@ describes Mars Coordinated Time (<abbr title="Mars Coordinated Time">MTC</abbr>) and the diverse local time scales used by each landed mission on Mars.</li> -<li><a href="http://leapsecond.com/">LeapSecond.com</a> is +<li><a href="http://leapsecond.com">LeapSecond.com</a> is dedicated not only to leap seconds but to precise time and frequency in general. It covers the state of the art in amateur timekeeping, and how the art has progressed over the past few decades.</li> @@ -671,7 +683,7 @@ Bulletins</a> contains official publications of the International Earth Rotation and Reference Systems Service, which decides when leap seconds occur.</li> <li>The <a -href="http://six.pairlist.net/mailman/listinfo/leapsecs">Leap +href="https://pairlist6.pair.net/mailman/listinfo/leapsecs">Leap Second Discussion List</a> covers <a href="http://gauss.gge.unb.ca/papers.pdf/gpsworld.november99.pdf">McCarthy and Klepczynski's proposal to discontinue leap seconds</a>, @@ -685,7 +697,7 @@ contentious issue.</li> </ul> <h2>Time notation</h2> <ul> -<li>The <a href="http://unicode.org/cldr/">Unicode Common Locale Data +<li>The <a href="http://cldr.unicode.org">Unicode Common Locale Data Repository (<abbr>CLDR</abbr>) Project</a> has localizations for time zone names, abbreviations, identifiers, and formats. For example, it contains French translations for "Eastern European Summer Time", @@ -762,7 +774,7 @@ is called "<abbr>GMT</abbr>".</li> <li><a href="tz-art.htm">Time and the Arts</a></li> <li><a href="http://www.dmoz.org/Reference/Time/">Open Directory – Reference: Time</a></li> -<li><a href="http://dir.yahoo.com/Science/Measurements_and_Units/Time">Yahoo! +<li><a href="https://dir.yahoo.com/science/measurements_and_units/time">Yahoo! Directory > Science > Measurements and Units > Time</a></li> </ul> <hr> |