EST to IRST Time Converter
IRST is 7 hours and 30 minutes ahead of EST. The US East Coast is currently on EDT (UTC-4:00), and IRST is UTC+3:30.
Best Time to Call Between EST and IRST
Both zones are inside normal business hours between 9:00 AM and 10:00 AM EST — that's 4:30 PM to 5:30 PM IRST. That's a 1-hour window.
both at work EST only IRST only neither — hours along the strip are EST.
Common Times Converted
EST on the left, IRST on the right.
EST to IRST: Full 24-Hour Conversion Table
Shaded rows are working hours; the darker shade marks the hours when both zones are at work.
| EST | IRST | Working hours |
|---|---|---|
| 12:00 AM | 7:30 AM | — |
| 1:00 AM | 8:30 AM | — |
| 2:00 AM | 9:30 AM | IRST only |
| 3:00 AM | 10:30 AM | IRST only |
| 4:00 AM | 11:30 AM | IRST only |
| 5:00 AM | 12:30 PM | IRST only |
| 6:00 AM | 1:30 PM | IRST only |
| 7:00 AM | 2:30 PM | IRST only |
| 8:00 AM | 3:30 PM | IRST only |
| 9:00 AM | 4:30 PM | Both zones |
| 10:00 AM | 5:30 PM | EST only |
| 11:00 AM | 6:30 PM | EST only |
| 12:00 PM | 7:30 PM | EST only |
| 1:00 PM | 8:30 PM | EST only |
| 2:00 PM | 9:30 PM | EST only |
| 3:00 PM | 10:30 PM | EST only |
| 4:00 PM | 11:30 PM | EST only |
| 5:00 PM | 12:30 AM next day | — |
| 6:00 PM | 1:30 AM next day | — |
| 7:00 PM | 2:30 AM next day | — |
| 8:00 PM | 3:30 AM next day | — |
| 9:00 PM | 4:30 AM next day | — |
| 10:00 PM | 5:30 AM next day | — |
| 11:00 PM | 6:30 AM next day | — |
What EST and IRST Actually Are
EST — Eastern Standard Time
New York, Toronto, Washington DC, Atlanta, Miami, Boston. Standing at UTC-5:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to EST. Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.
Eastern Standard Time is only actually in force from early November to mid-March. For the other eight months the same region is on EDT, which is why so many EST conversions are quietly wrong.
IRST — Iran Standard Time
Tehran, Mashhad, Isfahan. Standing at UTC+3:30 as written, and the region does not change its clocks, so that offset holds all year. Iran abolished daylight saving in 2022, so the half-hour offset now holds all year.
Iran abolished daylight saving in 2022. Its half-hour offset is a deliberate compromise between the solar times of its western and eastern borders.
What This Means in Practice
Expect times on the half hour
IRST sits on a 30-minute offset rather than a whole hour, so a round number on one side is never a round number on the other. A 9:00 meeting becomes 30 minutes past the hour, which is exactly the detail calendar invitations get wrong when someone converts in their head.
This gap is not fixed
EST changes its clocks and IRST does not, so the difference between them moves by an hour twice a year. A recurring meeting set now will drift for one side from Sunday, November 1, 2026 unless someone resets it.
Major Cities in Each Zone
Cities on EST
Cities on IRST
Frequently Asked Questions
What is the time difference between EST and IRST?
IRST is 7 hours and 30 minutes ahead of EST. That is the live figure. Taken strictly as written, the gap between EST and IRST is 8 hours and 30 minutes — the two differ because at least one of these regions is currently on daylight saving.
What is 9:00 AM EST in IRST?
9:00 AM EST is 4:30 PM IRST.
What are the best hours to schedule a call between EST and IRST?
Between 9:00 AM and 10:00 AM EST, which is 4:30 PM to 5:30 PM IRST. Both sides are inside normal business hours through that window.
Does the difference between EST and IRST change during the year?
Yes. EST observes daylight saving and IRST does not, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, November 1, 2026.
Does EST always mean Eastern Standard Time?
Australia also uses EST for its own Eastern Standard Time (UTC+10), now more often written AEST.
Does IRST always mean Iran Standard Time?
Iran abolished daylight saving in 2022, so the half-hour offset now holds all year.