Tehran, Iran Kolkata, India

Tehran is in the +0330 timezone (UTC+3:30) and Kolkata is in the IST timezone (UTC+5:30). The time difference between them is 2 hours.

Use the timeline above to find overlapping business hours between Tehran and Kolkata. The "Best time to meet" card highlights the window where both cities are within working hours (9 AM – 6 PM local time).

Neither Tehran nor Kolkata observes Daylight Saving Time, so the time difference remains constant throughout the year.

Click the pencil icon next to the Tehran clock and type any time. The Kolkata clock will update instantly, showing the exact corresponding time. You can also pick a date to account for DST changes.