Convert UTC to IRST
IRST is 3 hours 30 minutes ahead of UTC. UTC is UTC+0 and IRST is UTC+3:30.
Right now: UTC · IRST
Best time to schedule a meeting
Standard 9–5 working hours overlap for 5 hours: 9:00 AM–2:00 PM UTC (12:00 PM–5:00 PM IRST). Schedule meetings inside that window.
| UTC | IRST | Suitable? |
|---|---|---|
| 9:00 AM | 12:30 PM | working hours |
| 10:00 AM | 1:30 PM | working hours |
| 11:00 AM | 2:30 PM | working hours |
| 12:00 PM | 3:30 PM | working hours |
| 1:00 PM | 4:30 PM | working hours |
| 2:00 PM | 5:30 PM | outside 9–5 |
| 3:00 PM | 6:30 PM | outside 9–5 |
| 4:00 PM | 7:30 PM | outside 9–5 |
| 5:00 PM | 8:30 PM | outside 9–5 |
UTC to IRST conversion table
| UTC | IRST |
|---|---|
| 12:00 AM | 3:30 AM |
| 1:00 AM | 4:30 AM |
| 2:00 AM | 5:30 AM |
| 3:00 AM | 6:30 AM |
| 4:00 AM | 7:30 AM |
| 5:00 AM | 8:30 AM |
| 6:00 AM | 9:30 AM |
| 7:00 AM | 10:30 AM |
| 8:00 AM | 11:30 AM |
| 9:00 AM | 12:30 PM |
| 10:00 AM | 1:30 PM |
| 11:00 AM | 2:30 PM |
| 12:00 PM | 3:30 PM |
| 1:00 PM | 4:30 PM |
| 2:00 PM | 5:30 PM |
| 3:00 PM | 6:30 PM |
| 4:00 PM | 7:30 PM |
| 5:00 PM | 8:30 PM |
| 6:00 PM | 9:30 PM |
| 7:00 PM | 10:30 PM |
| 8:00 PM | 11:30 PM |
| 9:00 PM | 12:30 AM (next day) |
| 10:00 PM | 1:30 AM (next day) |
| 11:00 PM | 2:30 AM (next day) |
About UTC
Coordinated Universal Time (UTC) is UTC+0. It is used in the global time standard, used by aviation, computing and science.
UTC is not a time zone. It is the reference all the others are defined against, and no country runs its civil clocks on it — the places at UTC+0 are on GMT or WET, which are separate things that happen to agree in winter. It never changes for daylight saving, which is exactly why servers, aviation, and every log file you will ever read are timestamped in it. The one irregularity is the leap second, inserted to keep UTC within a second of the Earth's rotation; the practice is due to be abandoned by 2035.
About IRST
Iran Standard Time (IRST) is UTC+3:30. It is used in Iran, all year.
Iran Standard Time is UTC+3:30. Iran ran daylight saving for decades and stopped in 2022, so material written before then puts the country half an hour further ahead in summer and is now wrong. Half-hour offsets are rare enough that scheduling tools sometimes round them, which turns a correct calculation into a thirty-minute error.
Does this gap change with the seasons?
Neither UTC nor IRST shifts with the seasons, so this 3.5-hour difference holds all year. That is unusual enough to be worth relying on: most cross-continental gaps move twice a year.
This is the reason scheduling systems store an IANA zone such as Etc/UTC rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.
Frequently asked questions
What time is 9:00 AM UTC in IRST?
9:00 AM UTC is 12:30 PM IRST.
Is IRST ahead of UTC?
IRST is 3 hours 30 minutes ahead of UTC.
Which time zone does this use?
UTC is UTC+0 and IRST is UTC+3:30. Both abbreviations denote a single fixed offset, so this conversion never shifts with daylight saving — what changes is which abbreviation a place is using at the time.