What is the time difference between Tehran and London?

London is 2 hours 30 minutes behind Tehran. That figure is current — it changes by an hour when either city starts or ends daylight saving, and the exact dates are listed above.

When is the best time to call London from Tehran?

Between 11:30–18:00 in Tehran, which is 09:00–15:30 in London. That is the only stretch where both cities are inside a 09:00–18:00 day.

Does Tehran observe daylight saving time?

No. Tehran stays on UTC+3:30 all year, so its clocks never move.

Does London observe daylight saving time?

Yes. London runs on UTC+0 in winter and UTC+1 in summer. The next change is on 2026-10-25, when clocks go back by 60 minutes.

If it is midday in Tehran, what time is it in London?

It is 09:30 in London, on the same calendar date. That holds for the current offsets; it shifts by an hour around the daylight saving dates listed above.

Which time zones do Tehran and London use?

Tehran uses Asia/Tehran, currently UTC+3:30, and London uses Europe/London, currently UTC+1 (BST). Those identifiers are the ones to use in code — abbreviations are ambiguous and offsets change.

Convert Tehran time to London time

Right now London runs 2 hours 30 minutes behind Tehran. That gap is not fixed: it moves when either city changes its clocks.

Convert a time

From

Date

Time

Converted time

—

The converter needs JavaScript to run. Everything below — offsets, daylight saving dates and the hour-by-hour table — is part of the page and works without it.

Hour by hour

Every hour of a day in Tehran, and what the clock reads in London at that same moment.

Tehran	London
00:00	21:30previous day
01:00	22:30previous day
02:00	23:30previous day
03:00	00:30
04:00	01:30
05:00	02:30
06:00	03:30
07:00	04:30
08:00	05:30
09:00	06:30
10:00	07:30
11:00	08:30
12:00	09:30
13:00	10:30
14:00	11:30
15:00	12:30
16:00	13:30
17:00	14:30
18:00	15:30
19:00	16:30
20:00	17:30
21:00	18:30
22:00	19:30
23:00	20:30

Daylight saving time

London changes its clocks; Tehran does not. The difference between them therefore shifts by an hour twice a year.

Tehran

Does not observe daylight saving time

Standard: UTC+3:30

London

Observes daylight saving time

Standard: UTC+0
Daylight: UTC+1
Next change: 2026-10-25 −60m

When you can actually talk

You have 6 hours 30 minutes of shared working time: 11:30–18:00 in Tehran, which is 09:00–15:30 in London.

Tehran 11:30–18:00London 09:00–15:30

Reference

The zone identifiers and offsets behind everything above.

	Tehran	London
IANA zone	Asia/Tehran	Europe/London
Abbreviation	UTC+3:30	BST
Standard offset	UTC+3:30	UTC+0
Daylight offset	—	UTC+1
Clock changes this year	0	2
Country	Iran	United Kingdom

Example, not the current time. Live times appear once the page loads.

Common questions

What is the time difference between Tehran and London?: London is 2 hours 30 minutes behind Tehran. That figure is current — it changes by an hour when either city starts or ends daylight saving, and the exact dates are listed above.
When is the best time to call London from Tehran?: Between 11:30–18:00 in Tehran, which is 09:00–15:30 in London. That is the only stretch where both cities are inside a 09:00–18:00 day.
Does Tehran observe daylight saving time?: No. Tehran stays on UTC+3:30 all year, so its clocks never move.
Does London observe daylight saving time?: Yes. London runs on UTC+0 in winter and UTC+1 in summer. The next change is on 2026-10-25, when clocks go back by 60 minutes.
If it is midday in Tehran, what time is it in London?: It is 09:30 in London, on the same calendar date. That holds for the current offsets; it shifts by an hour around the daylight saving dates listed above.
Which time zones do Tehran and London use?: Tehran uses Asia/Tehran, currently UTC+3:30, and London uses Europe/London, currently UTC+1 (BST). Those identifiers are the ones to use in code — abbreviations are ambiguous and offsets change.