- tz - lists.iana.org

FW: [Arthur David Olson: RE: tz list server problem?]
by Olson, Arthur David (NIH/NCI) June 8, 2004

June 8, 2004

Dag-Erling is not on the time zone mailing list; direct replies appropriately. --ado -----Original Message----- From: des(a)des.no [mailto:des@des.no] Sent: Monday, June 07, 2004 3:08 PM To: Olson, Arthur David (NIH/NCI) Cc: Garrett Wollman ... I was trying to suggest the following addition to etcetera: Index: etcetera =================================================================== RCS file: /home/ncvs/src/share/zoneinfo/etcetera,v retrieving revision 1.1.2.5 diff -u -r1.1.2.5 etcetera --- etcetera 6 Apr 2001 16:43:21 -0000 1.1.2.5 +++ etcetera 25 May 2004 16:38:14 -0000 @@ -16,6 +16,8 @@ # We want this to work even on installations that omit the other older names. Link Etc/GMT GMT +Link Etc/UTC UTC + Link Etc/UTC Etc/Universal Link Etc/UTC Etc/Zulu DES -- Dag-Erling Smørgrav - des(a)des.no

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Argentina's timezones blues
by Mariano Absatz May 27, 2004

May 27, 2004

Hi, It's somehow hard to find the normative for each Province, but, according to the press, in the next days more Provinces will join Mendoza in setting the clocks back an hour to UTC-04:00. From http://www.lanacion.com.ar/04/05/27/de_604825.asp http://www.clarin.com/diario/2004/05/27/elpais/p-00401.htm San Juan will do it at midnight Sunday 30th (yes, it's the night between Sunday and Monday, just don't ask, it gets worse yet) until October 17th. Tucumán will do it at midnight Monday 31th, and apparently, Chubut, La Rioja, Santa Cruz and Tierra del Fuego would do it also on Monday night. Santa Cruz is apparently waiting for a Provincial Congress confirmation (the other Provinces are using Governors' Decrees). San Luis would also change its tz on Monday night according to: http://www.lanacion.com.ar/04/05/27/de_604901.asp http://www.clarin.com/diario/2004/05/27/um/m-766786.htm The City of Buenos Aires, as well as the Provinces of Buenos Aires, Córdoba, Santa Fe, Entre Ríos and Corrientes confirmed they will NOT change the timezone this winter. The rest of the Provinces are supposed to be analyzing what to do... FWIW, Argentina consists of 23 Provinces and the Autonomous City of Buenos Aires: Ciudad de Buenos Aires (4) Buenos Aires (4) Catamarca Chaco Chubut (3) Córdoba (4) Corrientes (4) Entre Ríos (4) Formosa Jujuy La Pampa La Rioja (3) Mendoza (1) Misiones Neuquen Rio Negro Salta San Juan (2) San Luis (3) Santa Cruz (3) Santa Fe (4) Santiago del Estero Tierra del Fuego (3) Tucumán (3) (1) Already switched on May 23 (2) Would switch on May 30 (3) Would switch on May 31 (4) Would not switch this year FWIW, the districts included in (4) account for the most part of the population of the countries, including the cities where most corporations have their computers installed... Please... take into account that, except for (1) I'm taking this from the newspapers... I'll try to get some authoritative data, but I'm not sure if I'll be able... I'll keep informing you as this think develops... -- Mariano Absatz - El Baby mailto:baby@baby.com.ar http://www.baby.com.ar/ PGP KEYS: http://www.baby.com.ar/datos/personales.html#claves_pgp |\ _ _\\/'> Powered by Pegasus Mail /|__) http://www.pmail.com ) )\ ----------------------------------------------------------- Who are you going to believe, me or your own eyes? -- Groucho Marx

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Re: America/Sao_Paulo DST problem
by Ruby Ballen May 27, 2004

May 27, 2004

I just tested in my system and the time was correctly reported before and after the transition on Feb 14 23:59:59. RBallen

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RE: America/Sao_Paulo DST problem
by Olson, Arthur David (NIH/NCI) May 27, 2004

May 27, 2004

Here are a few lines of "zdump" output for America/Sao_Paulo: America/Sao_Paulo Sun Oct 19 03:00:00 2003 UTC = Sun Oct 19 01:00:00 2003 BRST isdst=1 America/Sao_Paulo Sun Feb 15 01:59:59 2004 UTC = Sat Feb 14 23:59:59 2004 BRST isdst=1 America/Sao_Paulo Sun Feb 15 02:00:00 2004 UTC = Sat Feb 14 23:00:00 2004 BRT isdst=0 America/Sao_Paulo Sun Oct 17 02:59:59 2004 UTC = Sat Oct 16 23:59:59 2004 BRT isdst=0 The important thing to note is at midnight on February 14 clocks are set back an hour. This means that there are two instants when a well-maintained Sao Paulo wall clock would read 11:00:00 PM on February 14 (as well as two instants when it would 11:00:01, 11:00:02, and so on through 11:59:59). The "my_date.c" program feeds year-mon-mday-hour-min-sec into mktime; the values being fed in lie in the "fall back" hour above. Mktime is supposed to return an instant when a wall clock shows the time that's been input to it; here, since there are two such instants (and since "tm_isdst" has been set to -1), mktime is allowed to pick either instant to return. It's luck of the draw that determines which instant mktime returns. --ado

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America/Sao_Paulo DST problem
by Stefano Scarponi May 27, 2004

May 27, 2004

Hi all, During an investigation about customer brazilian problem I downloaded your latest tz lib from "ftp://elsie.nci.nih.gov/pub/". I build and install the library on Linux Redhat 9. I created a simple "my_date.c" that perform a mktime into the range 00:00 - 14 Feb 2004 to 23:59 - 15 Feb 2004. The DST from Brasil Sao_Paulo is the following: file southamerica: Rule Brazil 2000 2001 - Oct Sun>=8 0:00 1:00 S Rule Brazil 2001 max - Feb Sun>=15 0:00 0 - Rule Brazil 2002 only - Nov 3 0:00 1:00 S Rule Brazil 2003 max - Oct Sun>=15 0:00 1:00 S So for the DST about Feb Sun>=15 at 0:00 I expected that the DST occurs at 0:00 15 Feb, but I saw that it occurs at 23:49 14 Feb as you can see from the output program. I set the TZ to TZ=America/Sao_Paulo ./my_date .. .. .. date =<day=14 hours=23 min=45> diff=-60 epoque=1076809501 DST=<1> date =<day=14 hours=23 min=46> diff=-60 epoque=1076809561 DST=<1> date =<day=14 hours=23 min=47> diff=-60 epoque=1076809621 DST=<1> date =<day=14 hours=23 min=48> diff=-60 epoque=1076809681 DST=<1> date =<day=14 hours=23 min=49> diff=-3660 epoque=1076813341 DST=<0> <-------- DST occurs here date =<day=14 hours=23 min=50> diff=-60 epoque=1076813401 DST=<0> date =<day=14 hours=23 min=51> diff=-60 epoque=1076813461 DST=<0> date =<day=14 hours=23 min=52> diff=-60 epoque=1076813521 DST=<0> date =<day=14 hours=23 min=53> diff=-60 epoque=1076813581 DST=<0> date =<day=14 hours=23 min=54> diff=-60 epoque=1076813641 DST=<0> .. .. I think that this is a bug because the DST is for 15 Feb at 0:00 and NOT 23:49 14 Feb. Do you have some suggestions or do you already knows about this problem? This is my "my_date.c" (See attached file: my_date.c) Thanks Stefano

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Now ready: tzcode2004a.tar.gz and tzdata2004a.tar.gz
by Olson, Arthur David (NIH/NCI) May 27, 2004

May 27, 2004

The files... ftp://elsie.nci.nih.gov/pub/tzcode2004a.tar.gz ...and... ftp://elsie.nci.nih.gov/pub/tzdata2004a.tar.gz ...are now available. In addition to the proposed changes circulated on the time zone mailing list by Paul Eggert, these include the changes to handle DST transitions that occur at the end of a month in some years but at the start of the following month in other years (these changes were circulated back in March). I've also added a copy of the correspondence that's the basis for claims about DST in the Navajo Nation. --ado

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Re: Beginner questions
by Ruby Ballen May 26, 2004

May 26, 2004

Well, yes. What I was trying to say is if it is possible to do this: - When the user enables automatic DST calculations, use the regular rules. - When the user disables automatic DST calculations, compute local time using the offset that the time zone has when it is in standard time, regardless of DST being in effect or not. It's a desire to have this option, but if it's difficult to achieve it's OK. Thanks tz-request@lecserver. nci.nih.gov To: RBallen(a)hypercom.com cc: tz(a)lecserver.nci.nih.gov 05/26/04 11:21 AM Subject: Beginner questions <<On Wed, 26 May 2004 08:11:51 -0700, Ruby Ballen <RBallen(a)hypercom.com> said: > 2) Is it possible to disable DST changes when using this library? > Say the user wants to move the clock forward/backward manually when > DST is in effect instead of the library doing it for him. This does not make sense. The clock per se is not changed during the DST transition, only the way local time is computed from UTC. -GAWollman

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Beginner questions
by Ruby Ballen May 26, 2004

May 26, 2004

Some questions about this library (please, keep in mind I'm new using it): 1) I was testing localtime() using US/Pacific as time zone and trying to see if transitions to DST were done correctly. So I set my local time to April 4 2004, 1:59 a.m.. Some minutes later the local time was correctly reported as April 4, 3:02. Then, I set my local time to October 31, 1:59 and I double checked that localtime() was in fact giving me 1:59. Two minutes later I was expecting the wall clock to go back one hour. It didn't. What am I doing wrong? 2) Is it possible to disable DST changes when using this library? Say the user wants to move the clock forward/backward manually when DST is in effect instead of the library doing it for him. Thanks a lot for you help. RBallen

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Re: Beginner questions
by Ruby Ballen May 26, 2004

May 26, 2004

It makes sense. Thanks. So if I set it to October 31, 00:59:00 and wait for an hour I should see the transition, right? Thanks a lot. bww(a)acm.org To: RBallen(a)hypercom.com 05/26/04 08:21 AM cc: Subject: Re: Beginner questions > Then, I set my local time to October 31, 1:59 and I double checked > that localtime() was in fact giving me 1:59. Two minutes later I was > expecting the wall clock to go back one hour. It didn't. What am I doing > wrong? There are two 01:59's on that day ... you set the time to the second, after which there is no transition.

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proposed tz changes for Argentina, Mongolia, Mars, etc.
by Paul Eggert May 24, 2004

May 24, 2004

Here are proposed changes to the tz data. The most urgent items are this weekend's emergency law in Mendoza, Argentina, and a correction to the daylight-saving rules in Mongolia, as these changes affect current time stamps. Changes affecting current time stamps: * Mendoza, Argentina moved its clocks back this weekend due to an emergency law designed to save energy. (This is unusual, as normally clocks are moved forward to save energy, but apparently the province uses a lot of electricity in the morning.) Thanks to Mariano Absatz for this item. * Mongolia does observe daylight-saving time. Thanks to Ganbold Ts. for this item. Changes affecting historical time stamps: * Fixes for time stamps before 1901 in Singapore and Kuala Lumpur. Thanks to Mok Ly Yng for this item. * Cuiaba, Brazil used normal Brazilian daylight-saving rules in 1994/1995. (Sorry, I forgot to write down who told me this.) * The names of time zones in Alaska didn't change officially until November 30, 1983, which means Alaska was officially observing "Yukon Time" for most of November 1983. (Thanks to Arthur David Olson for this item.) Administrative change to how hard links are created: * Link the old name "Navajo" to America/Shiprock, not America/Denver. Commentary fixes only: * Quite a bit of commentary added for the hot topic of time and time zones on Mars. * A cross-reference to Cyprus in the `europe' file. * Calcutta is now officially called `Kolkata'. * The Date and Time Gateway has moved from bsdi.com (which no longer exists) to twiki.org. * Joseph Myers's page on time in Britain has moved from student.cusu.cam.ac.uk to www.srcf.ucam.org. * Add URLs pointing to ICU, Joda Time, and Sun Java 1.4. =================================================================== RCS file: RCS/southamerica,v retrieving revision 2003.5 retrieving revision 2003.5.0.1 diff -pu -r2003.5 -r2003.5.0.1 --- southamerica 2003/12/15 14:31:42 2003.5 +++ southamerica 2004/05/24 07:26:59 2003.5.0.1 @@ -141,6 +141,13 @@ Rule Arg 2000 only - Mar Sun>=1 0:00 0 - # This kind of things had always been done this way in Argentina. # We are still -03:00 all year round in all of the country. # +# From Mariano Absatz (2004-05-21): +# Today it was officially published that the Province of Mendoza is changing +# its timezone this winter... starting tomorrow night.... +# http://www.gobernac.mendoza.gov.ar/boletin/pdf/20040521-27158-normas.pdf +# From Paul Eggert (2004-05-24): +# It's Law No. 7,210. This change is due to a public power emergency, so for +# now we'll assume it's for this year only. # # From Paul Eggert (2002-01-22): # <a href="http://www.spicasc.net/horvera.html"> @@ -232,6 +239,8 @@ Zone America/Mendoza -4:35:16 - LMT 1894 -4:00 - WART 1992 Oct 18 -3:00 Arg AR%sT 1999 Oct 3 -4:00 Arg AR%sT 2000 Mar 3 + -3:00 - ART 2004 May 23 + -4:00 - WART 2004 Oct 17 -3:00 - ART # Aruba @@ -389,8 +398,8 @@ Rule Brazil 1992 only - Oct 25 0:00 1:0 Rule Brazil 1993 only - Jan 31 0:00 0 - # Decree <a href="http://pcdsh01.on.br/HV942.htm">942</a> (1993-09-28) # adopted by same states, plus AM. -# Decree <a href="http://pcdsh01.on.br/HV1252.htm">1,252</a> (1994-09-22) -# adopted by same states, minus AM and MT. +# Decree <a href="http://pcdsh01.on.br/HV1252.htm">1,252</a> (1994-09-22; +# web page corrected 2004-01-07) adopted by same states, minus AM. # Decree <a href="http://pcdsh01.on.br/HV1636.htm">1,636</a> (1995-09-14) # adopted by same states, plus MT and TO. # Decree <a href="http://pcdsh01.on.br/HV1674.htm">1,674</a> (1995-10-13) @@ -536,8 +545,6 @@ Zone America/Campo_Grande -3:38:28 - LMT # # Mato Grosso (MT) Zone America/Cuiaba -3:44:20 - LMT 1914 - -4:00 Brazil AM%sT 1994 Sep 22 - -4:00 - AMT 1995 Sep 14 -4:00 Brazil AM%sT 2003 Sep 24 -4:00 - AMT # =================================================================== RCS file: RCS/europe,v retrieving revision 2003.5 retrieving revision 2003.5.0.1 diff -pu -r2003.5 -r2003.5.0.1 --- europe 2003/12/15 14:31:42 2003.5 +++ europe 2004/05/24 07:26:59 2003.5.0.1 @@ -707,6 +707,9 @@ Zone Europe/Sofia 1:33:16 - LMT 1880 # Croatia # see Serbia and Montenegro +# Cyprus +# See the `asia' file. + # Czech Republic # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Czech 1945 only - Apr 8 2:00s 1:00 S =================================================================== RCS file: RCS/asia,v retrieving revision 2003.5 retrieving revision 2003.5.0.1 diff -pu -r2003.5 -r2003.5.0.1 --- asia 2003/12/15 14:31:42 2003.5 +++ asia 2004/05/24 07:26:59 2003.5.0.1 @@ -380,7 +380,7 @@ Zone Asia/Dili 8:22:20 - LMT 1912 # India # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Calcutta 5:53:28 - LMT 1880 +Zone Asia/Calcutta 5:53:28 - LMT 1880 # Kolkata 5:53:20 - HMT 1941 Oct # Howrah Mean Time? 6:30 - BURT 1942 May 15 # Burma Time 5:30 - IST 1942 Sep @@ -1012,17 +1012,13 @@ Rule NBorneo 1935 1941 - Sep 14 0:00 0:2 Rule NBorneo 1935 1941 - Dec 14 0:00 0 - # # peninsular Malaysia -# From Paul Eggert (2003-11-01): # The data here are taken from Mok Ly Yng (2003-10-30) # <http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html>. -# Before 1901, Penang, Malacca and Singapore each had their own time zone; -# assume Kuala Lumpur used Malaccan time. # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Kuala_Lumpur 6:46:48 - LMT 1880 - 6:49:00 - MMT 1901 Jan 1 # Malacca Mean Time +Zone Asia/Kuala_Lumpur 6:46:46 - LMT 1901 Jan 1 6:55:25 - SMT 1905 Jun 1 # Singapore M.T. 7:00 - MALT 1933 Jan 1 # Malaya Time - 7:00 0:20 MALST 1936 + 7:00 0:20 MALST 1936 Jan 1 7:20 - MALT 1941 Sep 1 7:30 - MALT 1942 Feb 16 9:00 - JST 1945 Sep 12 @@ -1089,6 +1085,15 @@ Zone Indian/Maldives 4:54:00 - LMT 1880 # # [The province of Selenge is omitted from the above lists.] +# From Ganbold Ts., Ulaanbaatar <ganbold(a)micom.mng.net> (2004-04-17): +# Daylight saving occurs at 02:00 local time last Saturday of March. +# It will change back to normal at 02:00 local time last Saturday of +# September.... As I remember this rule was changed in 2001. +# +# From Paul Eggert (2004-04-17): +# For now, assume Rives McDow's informant got confused about Friday vs +# Saturday, and that his 2001 dates should have 1 added to them. + # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Mongol 1983 1984 - Apr 1 0:00 1:00 S Rule Mongol 1983 only - Oct 1 0:00 0 - @@ -1098,8 +1103,9 @@ Rule Mongol 1983 only - Oct 1 0:00 0 - Rule Mongol 1985 1998 - Mar lastSun 2:00s 1:00 S Rule Mongol 1984 1998 - Sep lastSun 2:00s 0 - # IATA SSIM (1999-09) says Mongolia no longer observes DST. -Rule Mongol 2001 only - Apr 27 2:00s 1:00 S -Rule Mongol 2001 only - Sep 28 2:00s 0 - +Rule Mongol 2001 only - Apr lastSat 2:00 1:00 S +Rule Mongol 2001 max - Sep lastSat 2:00 0 - +Rule Mongol 2002 max - Mar lastSat 2:00 1:00 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] # Hovd, a.k.a. Chovd, Dund-Us, Dzhargalant, Khovd, Jirgalanta @@ -1309,10 +1315,10 @@ Zone Asia/Riyadh 3:06:52 - LMT 1950 # The data here are taken from Mok Ly Yng (2003-10-30) # <http://www.math.nus.edu.sg/aslaksen/teaching/timezone.html>. # Zone NAME GMTOFF RULES FORMAT [UNTIL] -Zone Asia/Singapore 6:55:25 - LMT 1880 +Zone Asia/Singapore 6:55:25 - LMT 1901 Jan 1 6:55:25 - SMT 1905 Jun 1 # Singapore M.T. 7:00 - MALT 1933 Jan 1 # Malaya Time - 7:00 0:20 MALST 1936 + 7:00 0:20 MALST 1936 Jan 1 7:20 - MALT 1941 Sep 1 7:30 - MALT 1942 Feb 16 9:00 - JST 1945 Sep 12 =================================================================== RCS file: RCS/tz-link.htm,v retrieving revision 2003.5 retrieving revision 2003.5.0.1 diff -pu -r2003.5 -r2003.5.0.1 --- tz-link.htm 2003/12/15 14:31:42 2003.5 +++ tz-link.htm 2004/05/24 07:26:59 2003.5.0.1 @@ -9,7 +9,7 @@ <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="2003-09-21" /> +<meta name="DC.Date" content="2004-05-24" /> <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" /> @@ -99,8 +99,8 @@ Here are some recent links that may be o </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 -text-based point-and-click interface to tables of current time +<li><a href="http://twiki.org/cgi-bin/xtra/tzdate">Date and Time Gateway</a> +is a text-based point-and-click interface to tables of current time throughout the world.</li> <li>Fancier web interfaces, roughly in ascending order of complexity, include: <ul> @@ -157,6 +157,15 @@ href="http://www.perl.com/language/misc/ License</a>. DateTime::TimeZone also contains a script <code>tests_from_zdump</code> that generates test cases for each clock transition in the <code>tz</code> database.</li> +<li><a href="http://oss.software.ibm.com/icu/">International Components for +Unicode (ICU)</a> contains a C/C++ library for internationalization that +has a compiler from <samp>tz</samp> source into an ICU-specific format. +ICU is freely available under a BSD-style license.</li> +<li><a href="http://joda-time.sourceforge.net/">Joda Time - Java date +and time API</a> contains a class +<code>org.joda.time.tz.ZoneInfoCompiler</code> that compiles +<code>tz</code> source into a Joda-specific binary format. Joda Time +is freely available under a BSD-style license.</li> </ul> <h2>Other <code>tz</code> binary file readers</h2> <ul> @@ -177,6 +186,9 @@ under a BSD-style license.</li> </ul> <h2>Other <code>tz</code>-based time zone conversion software</h2> <ul> +<li><a href="http://java.sun.com/">Sun Java</a> releases since 1.4 +contain a copy of a recent <samp>tz</samp> database in a Java-specific +format.</li> <li><a href="http://www1.tip.nl/~t876506/AboutTimeZonesHC.html">HyperCard time zones calculator</a> is a HyperCard stack.</li> @@ -330,7 +342,7 @@ is Singapore in the "Wrong" Time Zone?</ history of legal time in Singapore and Malaysia.</dd> <dt>United Kingdom</dt> <dd><a -href="http://student.cusu.cam.ac.uk/~jsm28/british-time/">History of +href="http://www.srcf.ucam.org/~jsm28/british-time/">History of legal time in Britain</a> discusses in detail the country with perhaps the best-documented history of clock adjustments. The National Physical Laboratory also maintains an <a @@ -362,6 +374,11 @@ among time scales like TAI, TDB, TT and Space Flight - Reference Systems - Time Conventions</a> briefly explains interplanetary space flight timekeeping.</li> <li><a +href="http://www.giss.nasa.gov/tools/mars24/help/notes.html">Technical +Notes on Mars Solar Time as Adopted by the Mars24 Sunclock</a> briefly +describes Mars Coordinated Time (MTC) and the diverse local time +scales used by each landed mission on Mars.</li> +<li><a href="http://hpiers.obspm.fr/eop-pc/products/bulletins/bulletins.html">Bulletins maintained by the IERS EOP (PC)</a> contains official publications of the Earth Orientation Parameters Product Center of the =================================================================== RCS file: RCS/northamerica,v retrieving revision 2003.5 retrieving revision 2003.5.0.1 diff -pu -r2003.5 -r2003.5.0.1 --- northamerica 2003/12/15 14:36:18 2003.5 +++ northamerica 2004/05/24 07:26:59 2003.5.0.1 @@ -193,10 +193,6 @@ Rule US 1987 max - Apr Sun>=1 2:00 1:00 # Samoa standard time # The law doesn't give abbreviations. # -# From Paul Eggert (1995-12-19): -# Shanks uses 1983-10-30, not 1983-11-30, for the 1983 transitions. -# Go with Shanks. -# # From Paul Eggert (2000-01-08), following a heads-up from Rives McDow: # Public law 106-564 (2000-12-23) introduced the abbreviation # "Chamorro Standard Time" for time in Guam and the Northern Marianas. @@ -323,13 +319,14 @@ Zone America/Juneau 15:02:19 - LMT 1867 -8:00 US P%sT 1946 -8:00 - PST 1969 -8:00 US P%sT 1983 Oct 30 2:00 + -9:00 US Y%sT 1983 Nov 30 -9:00 US AK%sT Zone America/Yakutat 14:41:05 - LMT 1867 Oct 18 -9:18:55 - LMT 1900 Aug 20 12:00 -9:00 - YST 1942 -9:00 US Y%sT 1946 -9:00 - YST 1969 - -9:00 US Y%sT 1983 Oct 30 2:00 + -9:00 US Y%sT 1983 Nov 30 -9:00 US AK%sT Zone America/Anchorage 14:00:24 - LMT 1867 Oct 18 -9:59:36 - LMT 1900 Aug 20 12:00 @@ -338,6 +335,7 @@ Zone America/Anchorage 14:00:24 - LMT 1 -10:00 - CAT 1967 Apr -10:00 - AHST 1969 -10:00 US AH%sT 1983 Oct 30 2:00 + -9:00 US Y%sT 1983 Nov 30 -9:00 US AK%sT Zone America/Nome 12:58:21 - LMT 1867 Oct 18 -11:01:38 - LMT 1900 Aug 20 12:00 @@ -346,6 +344,7 @@ Zone America/Nome 12:58:21 - LMT 1867 O -11:00 - NST 1967 Apr -11:00 - BST 1969 -11:00 US B%sT 1983 Oct 30 2:00 + -9:00 US Y%sT 1983 Nov 30 -9:00 US AK%sT Zone America/Adak 12:13:21 - LMT 1867 Oct 18 -11:46:38 - LMT 1900 Aug 20 12:00 @@ -354,6 +353,7 @@ Zone America/Adak 12:13:21 - LMT 1867 O -11:00 - NST 1967 Apr -11:00 - BST 1969 -11:00 US B%sT 1983 Oct 30 2:00 + -10:00 US AH%sT 1983 Nov 30 -10:00 US HA%sT # Shanks writes that part of southwest Alaska (e.g. Aniak) # switched from -11:00 to -10:00 on 1968-09-22 at 02:00, =================================================================== RCS file: RCS/backward,v retrieving revision 2003.4 retrieving revision 2003.4.0.1 diff -pu -r2003.4 -r2003.4.0.1 --- backward 2003/10/06 13:32:20 2003.4 +++ backward 2004/05/24 07:26:59 2003.4.0.1 @@ -65,7 +65,7 @@ Link Africa/Tripoli Libya Link America/Tijuana Mexico/BajaNorte Link America/Mazatlan Mexico/BajaSur Link America/Mexico_City Mexico/General -Link America/Denver Navajo +Link America/Shiprock Navajo Link Pacific/Auckland NZ Link Pacific/Chatham NZ-CHAT Link Pacific/Pago_Pago Pacific/Samoa =================================================================== RCS file: RCS/Theory,v retrieving revision 2003.5 retrieving revision 2003.5.0.1 diff -pu -r2003.5 -r2003.5.0.1 --- Theory 2003/12/15 14:36:34 2003.5 +++ Theory 2004/05/24 07:26:59 2003.5.0.1 @@ -7,6 +7,7 @@ Names of time zone regions Time zone abbreviations Calendrical issues + Time and time zones on Mars ----- Time and date functions ----- @@ -504,3 +505,48 @@ convert to the Gregorian calendar until Source: H. Grotefend, _Taschenbuch der Zeitrechnung des deutschen Mittelalters und der Neuzeit_, herausgegeben von Dr. O. Grotefend (Hannover: Hahnsche Buchhandlung, 1941), pp. 26-28. + + +----- Time and time zones on Mars ----- + +Some people have adjusted their work schedules to fit Mars time. +Dozens of special Mars watches were built for Jet Propulsion +Laboratory workers who kept Mars time during the Mars Exploration +Rovers mission (2004). These timepieces look like normal Seikos and +Citizens but use Mars seconds rather than terrestrial seconds. + +A Mars solar day is called a "sol" and has a mean period equal to +about 24 hours 39 minutes 35.244 seconds in terrestrial time. It is +divided into a conventional 24-hour clock, so each Mars second equals +about 1.02749125 terrestrial seconds. + +The prime meridian of Mars goes through the center of the crater +Airy-0, named in honor of the British astronomer who built the +Greenwich telescope that defines Earth's prime meridian. Mean solar +time on the Mars prime meridian is called Mars Coordinated Time (MTC). + +Each landed mission on Mars has adopted a different reference for +solar time keeping, so there is no real standard for Mars time zones. +For example, the Mars Exploration Rover project (2004) defined two +time zones "Local Solar Time A" and "Local Solar Time B" for its two +missions, each zone designed so that its time equals local true solar +time at approximately the middle of the nominal mission. Such a "time +zone" is not particularly suited for any application other than the +mission itself. + +Many calendars have been proposed for Mars, but none have achieved +wide acceptance. Astronomers often use Mars Sol Date (MSD) which is a +sequential count of Mars solar days elapsed since about 1873-12-29 +12:00 GMT. + +The tz database does not currently support Mars time, but it is +documented here in the hopes that support will be added eventually. + +Sources: + +Michael Allison and Robert Schmunk, +"Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock" +<http://www.giss.nasa.gov/tools/mars24/help/notes.html> (2004-03-15). + +Jia-Rui Chong, "Workdays Fit for a Martian", Los Angeles Times +(2004-01-14), pp A1, A20-A21.

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