# Iran # From Roozbeh Pournader (2003-03-15): # This is an English translation of what I just found (originally in Persian). # The Gregorian dates in brackets are mine: # # Official Newspaper No. 13548-1370/6/25 [1991-09-16] # No. 16760/T233 H 1370/6/10 [1991-09-01] # # The Rule About Change of the Official Time of the Country # # The Board of Ministers, in the meeting dated 1370/5/23 [1991-08-14], # based on the suggestion number 2221/D dated 1370/4/22 [1991-07-13] # of the Country's Organization for Official and Employment Affairs, # and referring to the law for equating the working hours of workers # and officers in the whole country dated 1359/4/23 [1980-07-14], and # for synchronizing the official times of the country, agreed that: # # The official time of the country will should move forward one hour # at the 24[:00] hours of the first day of Farvardin and should return # to its previous state at the 24[:00] hours of the 30th day of # Shahrivar. # # First Deputy to the President - Hassan Habibi # # Update: President Ahmadinejad ignored the DST for Iranian Time on # 22 March 2006 # and Hamid Hashemi ( hamid@morva.net ) fixed the zonefile on # 22 March 2006 until 22 March 2007 # # From personal experience, that agrees with what has been followed # for at least the last 5 years. Before that, for a few years, the # date used was the first Thursday night of Farvardin and the last # Thursday night of Shahrivar, but I can't give exact dates.... # I have also changed the abbreviations to what is considered correct # here in Iran, IRST for regular time and IRDT for daylight saving time. # # From Roozbeh Pournader (2005-04-05): # The text of the Iranian law, in effect since 1925, clearly mentions # that the true solar year is the measure, and there is no arithmetic # leap year calculation involved. There has never been any serious # plan to change that law.... # # From Paul Eggert (2005-04-05): # Go with Shanks before September 1991, and with Pournader thereafter. # I used Ed Reingold's cal-persia in GNU Emacs 21.2 to check Persian dates, # stopping after 2037 when 32-bit time_t's overflow. # That cal-persia used Birashk's approximation, which disagrees with the solar # calendar predictions for the year 2025, so I corrected those dates by hand. # # From Oscar van Vlijmen (2005-03-30), writing about future # discrepancies between cal-persia and the Iranian calendar: # For 2091 solar-longitude-after yields 2091-03-20 08:40:07.7 UT for # the vernal equinox and that gets so close to 12:00 some local # Iranian time that the definition of the correct location needs to be # known exactly, amongst other factors. 2157 is even closer: # 2157-03-20 08:37:15.5 UT. But the Gregorian year 2025 should give # no interpretation problem whatsoever. By the way, another instant # in the near future where there will be a discrepancy between # arithmetical and astronomical Iranian calendars will be in 2058: # vernal equinox on 2058-03-20 09:03:05.9 UT. The Java version of # Reingold's/Dershowitz' calculator gives correctly the Gregorian date # 2058-03-21 for 1 Farvardin 1437 (astronomical). # # Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Iran 1978 1980 - Mar 21 0:00 1:00 D Rule Iran 1978 only - Oct 21 0:00 0 S Rule Iran 1979 only - Sep 19 0:00 0 S Rule Iran 1980 only - Sep 23 0:00 0 S Rule Iran 1991 only - May 3 0:00 1:00 D Rule Iran 1992 1995 - Mar 22 0:00 1:00 D Rule Iran 1991 1995 - Sep 22 0:00 0 S Rule Iran 1996 only - Mar 21 0:00 1:00 D Rule Iran 1996 only - Sep 21 0:00 0 S Rule Iran 1997 1999 - Mar 22 0:00 1:00 D Rule Iran 1997 1999 - Sep 22 0:00 0 S Rule Iran 2000 only - Mar 21 0:00 1:00 D Rule Iran 2000 only - Sep 21 0:00 0 S Rule Iran 2001 2003 - Mar 22 0:00 1:00 D Rule Iran 2001 2003 - Sep 22 0:00 0 S Rule Iran 2004 only - Mar 21 0:00 1:00 D Rule Iran 2004 only - Sep 21 0:00 0 S Rule Iran 2005 2007 - Mar 22 0:00 0 S Rule Iran 2005 2007 - Sep 22 0:00 0 S Rule Iran 2008 only - Mar 21 0:00 1:00 D Rule Iran 2008 only - Sep 21 0:00 0 S Rule Iran 2009 2011 - Mar 22 0:00 1:00 D Rule Iran 2009 2011 - Sep 22 0:00 0 S Rule Iran 2012 only - Mar 21 0:00 1:00 D Rule Iran 2012 only - Sep 21 0:00 0 S Rule Iran 2013 2015 - Mar 22 0:00 1:00 D Rule Iran 2013 2015 - Sep 22 0:00 0 S Rule Iran 2016 only - Mar 21 0:00 1:00 D Rule Iran 2016 only - Sep 21 0:00 0 S Rule Iran 2017 2019 - Mar 22 0:00 1:00 D Rule Iran 2017 2019 - Sep 22 0:00 0 S Rule Iran 2020 only - Mar 21 0:00 1:00 D Rule Iran 2020 only - Sep 21 0:00 0 S Rule Iran 2021 2023 - Mar 22 0:00 1:00 D Rule Iran 2021 2023 - Sep 22 0:00 0 S Rule Iran 2024 only - Mar 21 0:00 1:00 D Rule Iran 2024 only - Sep 21 0:00 0 S Rule Iran 2025 2027 - Mar 22 0:00 1:00 D Rule Iran 2025 2027 - Sep 22 0:00 0 S Rule Iran 2028 2029 - Mar 21 0:00 1:00 D Rule Iran 2028 2029 - Sep 21 0:00 0 S Rule Iran 2030 2031 - Mar 22 0:00 1:00 D Rule Iran 2030 2031 - Sep 22 0:00 0 S Rule Iran 2032 2033 - Mar 21 0:00 1:00 D Rule Iran 2032 2033 - Sep 21 0:00 0 S Rule Iran 2034 2035 - Mar 22 0:00 1:00 D Rule Iran 2034 2035 - Sep 22 0:00 0 S Rule Iran 2036 2037 - Mar 21 0:00 1:00 D Rule Iran 2036 2037 - Sep 21 0:00 0 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Asia/Tehran 3:25:44 - LMT 1916 3:25:44 - TMT 1946 # Tehran Mean Time 3:30 - IRST 1977 Nov 4:00 Iran IR%sT 1979 3:30 Iran IR%sT