Convert Iran Standard Time to Greenwich Mean Time
| IRST | GMT |
|---|---|
| 12:00 AM | 10:00 PM (-1) |
| 3:00 AM | 1:00 AM |
| 6:00 AM | 4:00 AM |
| 9:00 AM | 7:00 AM |
| 12:00 PM | 10:00 AM |
| 3:00 PM | 1:00 PM |
| 6:00 PM | 4:00 PM |
| 9:00 PM | 7:00 PM (+1) |
Iran Standard Time (IRST) is UTC+3:30 and Greenwich Mean Time (GMT) is UTC+0. The exact difference can vary due to Daylight Saving Time changes.
Use our converter above to find the exact time. Enter 9:00 in the IRST field to see the corresponding GMT time, accounting for current DST rules.
Iran Standard Time (IRST) is based on the Asia/Tehran timezone. DST observance depends on local regulations. Our converter automatically accounts for current DST rules.
When it is 9:00 AM IRST, it is 6.5:00 AM GMT. Greenwich Mean Time (GMT, UTC+0) is 3.5 hours behind Iran Standard Time (IRST, UTC+3:30). Your working-hours overlap window is 0.5:00 PM–5:00 PM IRST (9:00 AM–1.5:00 PM GMT).
| IRST | GMT |
|---|---|
| 12:00 AM | 9.5:00 PM (-1 day) |
| 3:00 AM | 0.5:00 AM |
| 6:00 AM | 3.5:00 AM |
| 9:00 AM | 6.5:00 AM |
| 12:00 PM | 9.5:00 AM |
| 3:00 PM | 0.5:00 PM |
| 6:00 PM | 3.5:00 PM |
| 9:00 PM | 6.5:00 PM |
Iran Standard Time (IRST): Tehran, Mashhad, Isfahan.
Greenwich Mean Time (GMT): London, Manchester, Dublin, Edinburgh.
IRST is UTC+3:30 and GMT is UTC+0, a difference of 3.5 hours. GMT is behind IRST. This difference can shift by an hour in either direction during Daylight Saving Time transitions — if one zone observes DST and the other doesn't, the offset narrows or widens for part of the year.
Assuming a 9:00 AM – 5:00 PM workday on each side, your working-hours overlap window is 0.5:00 pm–5:00 pm irst (9:00 am–1.5:00 pm gmt). To visualize this instantly for any pair of cities, use the visual meeting planner or the timezone overlap finder — both highlight the green overlap window on a live timeline.
Iran Standard Time (IRST) is based on the Asia/Tehran IANA timezone. DST observance depends on the jurisdiction — for example, most of the continental US switches between standard and daylight time, while India, Japan, and most of Southeast Asia do not observe DST at all. WorldClock.lol uses the authoritative IANA timezone database, so every conversion automatically accounts for the correct DST rules on the date you're converting.
When it is 9:00 AM in Iran Standard Time (IRST, UTC+3:30), it is 6.5:00 AM in Greenwich Mean Time (GMT). For other times of day, scan the conversion table above or drop into the interactive converter to pick an exact minute. The converter handles both standard and daylight variants correctly.