Time in Kolkata vs Tehran
Kolkata keeps IST (UTC+5:30) and Tehran keeps UTC+3:30 (UTC+3:30) today. Tehran is 2 hours behind Kolkata; the rows below read both clocks live.
The working day, side by side
Hours shaded in both rows are inside working hours in both cities: 09:00–16:00 in Tehran (11:00–18:00 your time).
| City | 00:00 in Kolkata | 01:00 in Kolkata | 02:00 in Kolkata | 03:00 in Kolkata | 04:00 in Kolkata | 05:00 in Kolkata | 06:00 in Kolkata | 07:00 in Kolkata | 08:00 in Kolkata | 09:00 in Kolkata | 10:00 in Kolkata | 11:00 in Kolkata | 12:00 in Kolkata | 13:00 in Kolkata | 14:00 in Kolkata | 15:00 in Kolkata | 16:00 in Kolkata | 17:00 in Kolkata | 18:00 in Kolkata | 19:00 in Kolkata | 20:00 in Kolkata | 21:00 in Kolkata | 22:00 in Kolkata | 23:00 in Kolkata |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Kolkata—— | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 |
| Tehran—— | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 |
- Working hours
- Shoulder
- Night
- Overlap
Do more with Kolkata and Tehran
Best hours to call
11:00 in Kolkata
Inside working hours on both sides
09:00 in Tehran
12:00 in Kolkata
Inside working hours on both sides
10:00 in Tehran
13:00 in Kolkata
Inside working hours on both sides
11:00 in Tehran
14:00 in Kolkata
Inside working hours on both sides
12:00 in Tehran
Where daylight saving pulls them apart
Neither Kolkata nor Tehran changes its clocks, so the gap above holds all year.
Also useful
Common questions
How many hours ahead is Tehran of Kolkata?
Tehran is 2 hours behind Kolkata right now. The gap is not fixed: it moves whenever either side changes its clocks.
What is the best time to call between Kolkata and Tehran?
Any hour in 11:00–18:00 Kolkata time is inside working hours in both cities.
Do Kolkata and Tehran change clocks on the same date?
Neither city changes its clocks, so the gap between them never moves.