Iran Standard Time

Between 2005 and 2008, by decree of President Mahmoud Ahmadinejad, Iran did not observe daylight saving time (DST) (called Iran Daylight Time or IRDT).

On 21 September 2022, Iran abolished DST and now observes standard time year-round.

This resulted in the unique situation wherein the dates of DST transitions didn't 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.

DST likewise ended in Iran at 24:00 on 30 Shahrivar, which corresponds to either 20 or 21 September.