IRST to IST Time Converter
Convert Iran Standard Time to India Standard Time. Right now, IRST is 2 hours behind IST.
IRST · Tehran
11:04 PM
UTC +3:30 · Iran
IST · Delhi
1:04 AM
UTC +5:30 · India
Time across cities
Time Zone Converter
Click any hour to see what it lands on in every city. The first row's hours run 12am to 11pm — every other row is its local time at the same instant.
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Tehran
UTC +3:30anchor
Delhi
UTC +5:30
Right now
Tehran
11:04 PM
Sat, May 9
Delhi
1:04 AM
Sun, May 10
Quick reference
When it's this time in Tehran:
| Tehran | Delhi |
|---|---|
| 6:00 AM | 8:00 AM |
| 9:00 AM | 11:00 AM |
| 12:00 PM | 2:00 PM |
| 3:00 PM | 5:00 PM |
| 6:00 PM | 8:00 PM |
| 9:00 PM | 11:00 PM |
About IRST and IST
IRST (Iran Standard Time) covers Iran and is anchored to the IANA zone Asia/Tehran. It does not observe daylight saving time — the offset stays fixed all year.
IST (India Standard Time) covers India via Asia/Kolkata. It does not observe daylight saving time.
Neither IRST nor IST observes DST, so the offset between them is constant year-round at 2 hours.
FAQ
- How many hours difference between IRST and IST?
- Right now, IRST is 2 hours behind IST. Because neither zone observes daylight saving time, this gap stays constant year-round.
- What time is 9 AM IRST in IST?
- 9 AM IRST (Tehran) is 11:00 AM IST (Delhi) today. Click any cell in the grid above to convert other times — the math handles DST and half-hour offsets correctly.
- Does IRST observe daylight saving time?
- No. Iran Standard Time stays at a fixed offset year-round. The hour grid above will show the same difference whether you check in summer or winter.
- What's the IANA timezone identifier for IRST and IST?
- IRST → Asia/Tehran. IST → Asia/Kolkata. We use IANA identifiers (not GMT offsets) as the source of truth so historical and future dates remain accurate, including across DST changes and political timezone shifts.
- Where can I see the overlap between IRST and IST working hours?
- Click "Working hrs" in the toolbar above to highlight hours where all selected cities have overlapping business hours. The amber highlight shows which columns work for scheduling meetings across time zones.
- Which countries use IRST and IST?
- IRST (Iran Standard Time) is used in Iran. IST (India Standard Time) is used in India. If you're converting time between any of these countries, this is the right page.