# When can I ring Tehran from London?

Iran no longer changes its clocks, so the gap with London moves only with the UK’s changes in March and October. If a time website shows Iran on summer time, it is out of date.

A call in your morning reaches them around lunchtime. Your evening is late at night in Tehran.

## Through the year

We assume you are up from 7:00 to 22:00 and that 9:00 to 21:00 is a fair time for them to take a call. Change the hours in the tool above if they keep others.

- 14 November 2026 to 28 March 2027Tehran is 3 hours and 30 minutes ahead of London.Good time to ring: 7:00 to 17:30, your time (10:30 to 21:00 in Tehran).
- 28 March 2027 to 31 October 2027Tehran is 2 hours and 30 minutes ahead of London.Good time to ring: 7:00 to 18:30, your time (9:30 to 21:00 in Tehran).
- 31 October 2027 to 31 December 2027Tehran is 3 hours and 30 minutes ahead of London.Good time to ring: 7:00 to 17:30, your time (10:30 to 21:00 in Tehran).

## When the clocks change

- London: clocks go forward 1 hour on Sunday 28 March 2027, at 1:00 local time.
- London: clocks go back 1 hour on Sunday 31 October 2027, at 2:00 local time.
- Tehran does not change its clocks in this period.
- Tehran last changed its clocks on 22 September 2022.

Time zones: London uses Europe/London and Tehran uses Asia/Tehran in the IANA time-zone database, version 2026f. Dates are worked out from it; a government can change its clocks at short notice.