Iran Standard Time
Iran Standard Time or Iran Time 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, 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 . It was reintroduced from 21 March 2008. On 21 September 2022, Iran abolished DST and now observes standard time year-round.
Daylight Saving Time transitions
The dates of DST transitions in Iran were based on the Solar Hijri calendar, the official calendar of Iran, which is in turn based on the March equinox as determined by astronomical calculation at the meridian for Iran Standard Time. This resulted in the unique situation wherein the dates of DST transitions did not fall on the same weekday each year as they do in most other countries.DST started 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. Clocks moved forward at that time to 01:00 on 2 Farvardin. This spring change took place at the end of the day of Nowruz, which is the Iranian New Year's Day and the most important festival in Iranian culture.
DST likewise ended in Iran at 24:00 on 30 Shahrivar, which corresponds to either 20 or 21 September.. Clocks moved backward to 23:00 on 30 Shahrivar.