Convert IRST to EST
EST is 8 hours 30 minutes behind IRST. IRST is UTC+3:30 and EST is UTC−5.
Right now: IRST · EST
Best time to schedule a meeting
Standard 9–5 working hours do not overlap at all between IRST and EST. Someone has to take an early or late call — or use asynchronous communication instead.
| IRST | EST | Suitable? |
|---|---|---|
| 9:00 AM | 12:30 AM | outside 9–5 |
| 10:00 AM | 1:30 AM | outside 9–5 |
| 11:00 AM | 2:30 AM | outside 9–5 |
| 12:00 PM | 3:30 AM | outside 9–5 |
| 1:00 PM | 4:30 AM | outside 9–5 |
| 2:00 PM | 5:30 AM | outside 9–5 |
| 3:00 PM | 6:30 AM | outside 9–5 |
| 4:00 PM | 7:30 AM | outside 9–5 |
| 5:00 PM | 8:30 AM | outside 9–5 |
IRST to EST conversion table
| IRST | EST |
|---|---|
| 12:00 AM | 3:30 PM (previous day) |
| 1:00 AM | 4:30 PM (previous day) |
| 2:00 AM | 5:30 PM (previous day) |
| 3:00 AM | 6:30 PM (previous day) |
| 4:00 AM | 7:30 PM (previous day) |
| 5:00 AM | 8:30 PM (previous day) |
| 6:00 AM | 9:30 PM (previous day) |
| 7:00 AM | 10:30 PM (previous day) |
| 8:00 AM | 11:30 PM (previous day) |
| 9:00 AM | 12:30 AM |
| 10:00 AM | 1:30 AM |
| 11:00 AM | 2:30 AM |
| 12:00 PM | 3:30 AM |
| 1:00 PM | 4:30 AM |
| 2:00 PM | 5:30 AM |
| 3:00 PM | 6:30 AM |
| 4:00 PM | 7:30 AM |
| 5:00 PM | 8:30 AM |
| 6:00 PM | 9:30 AM |
| 7:00 PM | 10:30 AM |
| 8:00 PM | 11:30 AM |
| 9:00 PM | 12:30 PM |
| 10:00 PM | 1:30 PM |
| 11:00 PM | 2:30 PM |
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.
About EST
Eastern Standard Time (EST) is UTC−5. It is used in New York, Toronto, Miami and Atlanta in winter.
Eastern Standard Time is UTC−5 and applies in New York, Toronto, Miami and Atlanta only from November to March. For the other eight months those cities are on EDT, UTC−4. Americans routinely write "EST" year-round to mean "east coast time", so a date given as EST in July is usually meant as EDT and is an hour earlier than written — one of the most common scheduling errors there is. Note also that Panama and Jamaica are on UTC−5 all year and never switch.
Does this gap change with the seasons?
This gap is seasonal. The abbreviations themselves are fixed offsets, but the region on EST switches to EDT (UTC−4) from March to November. So the 8.5-hour figure on this page is correct for the part of the year when both places are actually on these abbreviations, and changes by an hour outside it.
IRST does not shift, so the whole change comes from one side. A recurring meeting fixed in IRST will appear to move by an hour for everyone on the other side, twice a year, without anyone changing anything.
This is the reason scheduling systems store an IANA zone such as Region/City 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 IRST in EST?
9:00 AM IRST is 12:30 AM EST.
Is EST ahead of IRST?
EST is 8 hours 30 minutes behind IRST.
Which time zone does this use?
IRST is UTC+3:30 and EST is UTC−5. 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.