Iran Standard Time: Difference between revisions

'''Iran Standard Time''' ('''IRST''') or '''Iran Time''' ('''IT''') is the [[time zone]] used in [[Iran]]. Iran uses a UTC offset [[UTC+03:30]]. IRST is defined by the 52.5 degrees east [[meridian (geography)|meridian]], the same meridian which defines the [[Iranian calendar]] and is the official meridian of Iran.

Between 2005 and 2008, by decree of President [[Mahmoud Ahmadinejad]], Iran did not observe [[daylight saving time]] (DST) (called ''Iran Daylight Time'' or ''IRDT'').<ref>{{cite web|url=http://wwwtimeanddate.presstv.ircom/detailworldclock/timezone.aspxhtml?idn=3243&sectionid=351020102246 |title=Time zone and daylight saving time for Iran will– notTehran observebetween DST2010 and 2019 |publisher=PresstvTimeanddate.ircom |access-date=20 March 2007 |accessdate=9 May 2010}}</ref> It was reintroduced from 21 March 2008. On 21 September 2022, Iran abolished DST and now observes standard time year-round.<ref>{{cite web|url=httphttps://www.timeanddate.com/worldclocknews/timezonetime/iran-dst-2022.html?n=246 |title=Time zone and daylight saving time for Iran –Considers Tehran between 2010 and 2019Abolishing DST|publisherwebsite=Timeanddatetimeanddate.com |date= |accessdate=913 May 20102022}}</ref><ref>{{cite Itweb|url=https://livingintehran.com/2022/09/21/daylight-saving-time-ends-in-iran/|date=2022-09-21|title=Daylight wasSaving reintroducedTime fromEnds 21in March 2008Iran|website=Livingintehran.com}}</ref>

The dates of DST transitions in Iran arewere based on the [[Solar Hijri calendar]], the official calendar of [[Iran]], which is in turn based on the [[March equinox]] ([[Nowruz]]) as determined by astronomical calculation at the [[Meridian (geography)|meridian]] for Iran Standard Time (52.5°E or GMT+3.5h). This resultsresulted in the unusualunique situation wherein the dates of DST transitions dondidn't fall on the same weekday each year as they do in most other countries.

DST startsstarted in Iran at 24:00 on '''1 [[Farvardin]],''' which corresponds to either 20 or 21 March in the [[Gregorian calendar]], depending on the precise timing of the equinox. (This is equivalent to 00:00 on 2 Farvardin, either 21 or 22 March.) Clocks movemoved forward at that time to 01:00 on 2 Farvardin (21 or 22 March). This spring change takestook place at the end of the day of [[Nowruz]], which is the [[Iranian peoples|Iranian]] [[New Year|New Year's Day]]<ref>{{Cite web|title = Culture of Iran: No-Rooz, The Iranian New Year at Present Times|url = http://www.iranchamber.com/culture/articles/norooz_iranian_new_year.php|website = www.iranchamber.com|access-date = 1 February 2016}}</ref> and the most important festival in Iranian culture.

DST likewise endsended in Iran at 24:00 on '''30 [[Shahrivar]],''' which corresponds to either 20 or 21 September. (Equivalently, at 00:00 on 31 Shahrivar, either 21 or 22 September). Clocks movemoved backward to 23:00 on 30 Shahrivar (20 or 21 September).<ref>{{cite web |url=https://mm.icann.org/pipermail/tz/2003-March/012052.html |title=Iran daylight saving time correction |author=Roozbeh Pournader |date=15 March 2003 |accessdateaccess-date=1 December 2018}}</ref><ref>{{cite web |url=https://github.com/eggert/tz/blob/d053d36c480fcf2fe6d37636da9eff1b8eddca70/asia#L1278-L1299 |title=<code>asia</code> file, lines 1278–1299 |author=[[tz database |website=[[GitHub]] |author-link=tz database |date=30 November 2018 |accessdateaccess-date=1 December 2018}}</ref>

|! '''Period in use'''

|! '''Time offset from GMT'''

|! '''Name of Time'''time

| 1800 –before 1945

| 2008 – present2022