Iran uses IRST (Iran Standard Time, UTC+3:30) year-round. DST was abolished in September 2022. IANA: Asia/Tehran.

Key facts about time in Iran

  • Timezone: Iran Standard Time (IRST)
  • UTC offset: +03:30 (year-round since September 2022)
  • DST: No (abolished September 21, 2022)
  • IANA identifier: Asia/Tehran
  • Capital: Tehran

Iran occupies a singular position in the world’s timezone map. It uses UTC+3:30 year-round. This half-hour offset makes Iran one of the more unusual clock situations on earth. DST was abolished on September 21, 2022, and Iran no longer changes its clocks seasonally.

Why UTC+3:30?

Iran’s geographic center sits at approximately 55 degrees East longitude. UTC+3 would correspond to 45 degrees East; UTC+4 to 60 degrees East. Iran’s longitude puts it naturally between the two, and the government chose UTC+3:30 as a compromise.

This is the same logic behind several other half-hour offset countries: India (UTC+5:30), Sri Lanka (UTC+5:30), Afghanistan (UTC+4:30), and Australia’s Northern Territory (UTC+9:30). Where the geography sits awkwardly between whole-hour options, a half-hour split can serve better than committing to either extreme.

The Iranian calendar alongside the clock

Iran officially uses the Solar Hijri calendar (the Jalali calendar, reformed in 1925), not the Gregorian calendar. The Iranian New Year, Nowruz, falls on the spring equinox, usually March 20 or 21. The year is numbered from the migration of the Prophet Muhammad from Mecca to Medina in 622 CE, but calculated in solar years rather than the lunar years used by most Islamic countries.

This means that Iran’s official date is different from the Gregorian date. As of 2026, Iran is in year 1404-1405 of the Solar Hijri calendar.

When Iran observed DST, transitions were anchored to the Iranian calendar, not the Gregorian. Clocks sprang forward at Nowruz (the Iranian New Year, around March 21) and fell back near the end of Shahrivar (around September 22). DST was abolished in September 2022; Iran now observes standard time year-round.

Nowruz and the spring clock

Nowruz is one of the world’s oldest continuously observed holidays. Celebrations of the spring equinox in the Persian cultural sphere date back at least 3,000 years. It is observed not just in Iran but across Central Asia, the Caucasus, parts of South Asia, and communities of the Iranian diaspora worldwide.

The traditions of Nowruz include haft-seen (a ceremonial table with seven items beginning with the letter S in Persian), spring cleaning, visiting relatives, and the moment of the new year itself, marked precisely at the astronomical equinox. Television and radio broadcasts count down to the exact second of the equinox.

This is extraordinarily precise solar timekeeping, calibrated to the exact astronomical moment rather than to any conventional clock boundary. The equinox happens when it happens; the Iranian New Year happens at that moment.

DST in an Islamic republic

Iran used to be one of the few predominantly Muslim countries to observe daylight saving time. Several of Iran’s neighbors, including Afghanistan (UTC+4:30, no DST), Pakistan (UTC+5, no DST), and most of the Arab Gulf states, do not observe DST. Iran’s DST practice persisted through the 1979 Islamic Revolution but was ultimately abolished on September 21, 2022.

Tehran’s traffic and informal time

Tehran is a metropolis of approximately 10 million people (15 million in greater metro), with traffic congestion that is genuinely remarkable. The concept of punctuality in Tehran’s social culture is somewhat more relaxed than in, say, Germany or Japan. Informal social engagements typically start later than stated, and the culture accommodates this.

The half-hour offset can be a minor source of confusion in international calls: Iran is never on any “round” timezone, so the mental arithmetic of “what time is it in Tehran” requires an extra step for most callers.

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