Timezone abbreviation
IRDT currently resolves here through Asia/Tehran, where the live offset is +03:30 (GMT+3:30). This page expands that into the broader meaning set, top cities, countries, similar labels, and safer exact-zone equivalents.
Last updated Apr 26, 2026. Representative zones, offset ranges, and city usage are refreshed from the current timezone dataset so abbreviation pages stay tied to real zones instead of static boilerplate.
IRDT is an Asian civil-time label, currently 3.5h ahead of UTC at +03:30. The lead reference is Tehran, and the wider grouping reaches 1 country through 1 IANA zone.
The busiest cities using IRDT in the current catalog are Tehran, Mashhad, Isfahan, Karaj, and Tabriz. The lead live reference on this page is Tehran (Asia/Tehran), currently at +03:30 (GMT+3:30). Those cities are what give IRDT its actual feel rather than the abstract offset.
IRDT is stable on Asia/Tehran year-round, with no seasonal clock changes in the next year. That makes it a low-friction choice for recurring meetings and broadcast schedules — but software still prefers the IANA zone because governments can change civil-time rules independently of the short code.
Live reference
Asia/Tehran
Current offset
+03:30 (GMT+3:30)
Meanings / zones / countries
1 / 1 / 1
Offset range
UTC+03:30
IRDT is well ahead of UTC, which usually means it is read inside Asia, the Middle East, or the Indian Ocean rim. In practice it is read inside Middle East and West Asia, where the leading city anchors are Tehran, Iran, Mashhad, Iran, and Isfahan, Iran.
IRDT is unusually unambiguous: it ties to a single country and a single IANA zone, which is closer to a national clock label than a multi-region abbreviation.
IRDT shows up on energy-market schedules, regional aviation, and Gulf-area broadcast guides. IRDT stays on a single offset year-round in the current data, which simplifies its operational use.
Iran sits in Asia, specifically Southern Asia. Population 85,961,000, area 1,648,195 km², capital Tehran. Civic markers behind IRDT include Persian (Farsi) and IRR (Iranian rial, ﷼).
Tehran is the clearest city-level anchor: Tehran is the capital and largest city of Iran. It is also the capital of Tehran province and the administrative center for Tehran County and its Central District. With a population of around 9 million in the city, and 16.8 million in the metropolitan area, Tehran is the most populous city in Iran and West Asia, the second-largest metropolitan area in the Middle East after Cairo, and the 24th-most-populous metropolitan area in the world. Greater Tehran includes several municipalities, including Karaj, Eslamshahr, Shahriar, Qods, Malard, Golestan, Varamin, Pakdasht, Qarchak, Nasimshahr, Parand, Pardis, Andisheh and Fardis.
IRDT in the Iran Time meaning runs 3h30m ahead of UTC through Middle East and West Asia, threading zones such as Asia/Tehran (cities: Tehran, Mashhad, and Isfahan). Country anchors: Iran.
Iran Time
Current reading: GMT+3:30 at +03:30 in Iran.
Asia/Tehran does not show a scheduled offset change in the next year, so the current offset can be treated as operationally stable for short-term planning.
City anchors include Tehran, Mashhad, and Isfahan, while country anchors include Iran.
Live reference zone: Asia/Tehran (GMT+3:30, +03:30)
Leading city in the current dataset: Tehran, Iran.
Cities: Tehran, Iran, Mashhad, Iran, and Isfahan, Iran. Countries: Iran.
Live zones: Asia/Tehran (+03:30).
Countries
Iran
Top cities
Tehran, Mashhad, Isfahan, Karaj
Iran spans 1 zone (329 cities) under IRDT. Visible cities: Tehran, Mashhad, and Isfahan. Underlying zones: Asia/Tehran.
City anchors for IRDT (Middle East and West Asia, currently +03:30). Pick a city to drop into a live local clock.
Iran
Cities: Tehran, Mashhad, Isfahan, Karaj
Meaning group: Iran Time
IRDT resolves cleanly here, but Asian labels often share letters with American or European ones — IST is shared between India and Israel, for instance. Pinning Asia/Tehran avoids that whole class of confusion.
Asia/Tehran does not show an offset change in the next year, which makes IRDT predictable for short-term scheduling. Predictable is not the same as permanent — civil-time rules still get changed by governments on relatively short notice.
For precise work, the safest equivalent of IRDT is the exact IANA zone used by your city or system. Asia/Tehran sits at +03:30, ahead of UTC, which means daily logs in this zone reach a new calendar date before UTC does — a small detail that breaks date-based reporting if missed.
Within this single zone (Asia/Tehran, +03:30), IRDT is unambiguous, so the abbreviation and the IANA zone effectively interchange.
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