Convert IST to IRST — Time Difference Between India Standard Time and Iran Standard Time
Drag the slider or click the time display to type a specific hour and instantly convert IST to IRST — Iran Standard Time is 2 hours behind India Standard Time. Scroll down to browse the full IST to IRST conversion table, check what time 9 AM, 10 AM, 11 AM, or 12 PM in Kolkata is in Tehran, and use the date picker to compare times on any day for accurate scheduling.
IST
India Standard Time
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IRST
Iran Standard Time
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IST to IRST Time Zone Difference — Hour-by-Hour Conversion Table
Scan each row to find what time any hour in Kolkata is in Tehran — tap the arrows to jump between days, click "Today" to reset, and use the color-coded bands to quickly spot overlapping work hours, early mornings, and late nights at a glance.
| IST (Kolkata) | IRST (Tehran) |
|---|
How to Convert IST to IRST
Drag the slider on the IST timeline to pick your time — the IRST time updates instantly. You can also click the time display to type a specific hour or pick one from the 15-minute interval dropdown, and use the date picker to check a different day.
What Is the Time Difference Between IST and IRST?
Iran Standard Time (IRST) is 2 hours behind India Standard Time (IST). To convert, subtract 2 hours — for example, 9:00 AM IST is 7:00 AM IRST.
What Time Is It Now in Kolkata?
What Time Is It Now in Tehran?
IST to IRST Quick Reference
IST to IRST Meeting Planner
Use the color-coded table above to find overlapping work hours between Kolkata and Tehran. Amber rows mark daytime hours — pick a slot that falls in amber on both sides for a meeting that works for everyone.
Why Trust This IST to IRST Converter?
Timezoney uses the IANA Time Zone Database — the same source that powers your phone and computer — so every conversion handles daylight saving transitions and half-hour offsets automatically.
India Standard Time
- Abbreviation
- IST
- UTC Offset
- UTC+5:30
- City
- Kolkata
- Country
- India
Iran Standard Time
- Abbreviation
- IRST
- UTC Offset
- UTC+3:30
- City
- Tehran
- Country
- Iran