BST to Tehran Time Converter
IRST is 3 hours 30 minutes ahead of GMT. 9:00 AM GMT = 12:30 PM IRST.
IRST is 3 hours 30 minutes ahead of GMT at the moment. To convert BST to Tehran Time, add 3 hours 30 minutes to the BST time: 9:00 AM GMT = 12:30 PM IRST.
BST (British Time) is used in United Kingdom from late March to late October. Tehran Time (Tehran time) is used in Tehran, Iran.
BST here means British Summer Time, not Bangladesh Standard Time. BST (British Summer Time) is not in force right now: United Kingdom from late March to late October is currently on GMT. This page uses whichever name applies on the date you pick, so the numbers below say GMT.
BST to Tehran Time time conversion table
BST to Tehran Time on 7 Nov 2026. Today's date. Highlighted rows are 9 AM–5 PM in both places.
| BST | Tehran Time | Day |
|---|---|---|
| 12:00 AM GMT | 3:30 AM IRST | night |
| 1:00 AM GMT | 4:30 AM IRST | night |
| 2:00 AM GMT | 5:30 AM IRST | night |
| 3:00 AM GMT | 6:30 AM IRST | — |
| 4:00 AM GMT | 7:30 AM IRST | — |
| 5:00 AM GMT | 8:30 AM IRST | — |
| 6:00 AM GMT | 9:30 AM IRST | — |
| 7:00 AM GMT | 10:30 AM IRST | — |
| 8:00 AM GMT | 11:30 AM IRST | — |
| 9:00 AM GMT | 12:30 PM IRST | work hours |
| 10:00 AM GMT | 1:30 PM IRST | work hours |
| 11:00 AM GMT | 2:30 PM IRST | work hours |
| 12:00 PM GMT | 3:30 PM IRST | work hours |
| 1:00 PM GMT | 4:30 PM IRST | work hours |
| 2:00 PM GMT | 5:30 PM IRST | — |
| 3:00 PM GMT | 6:30 PM IRST | — |
| 4:00 PM GMT | 7:30 PM IRST | — |
| 5:00 PM GMT | 8:30 PM IRST | — |
| 6:00 PM GMT | 9:30 PM IRST | — |
| 7:00 PM GMT | 10:30 PM IRST | night |
| 8:00 PM GMT | 11:30 PM IRST | night |
| 9:00 PM GMT | 12:30 AM IRST | next day |
| 10:00 PM GMT | 1:30 AM IRST | next day |
| 11:00 PM GMT | 2:30 AM IRST | next day |
- Work rows — 9 AM–5 PM in both places
- Night in the destination (10 PM–6 AM)
How to convert BST to Tehran Time
Add 3 hours 30 minutes to the BST time to get Tehran Time.
Example: 9:00 AM GMT = 12:30 PM IRST.
Across midnight: 10:00 PM GMT = 1:30 AM IRST (next day). The date changes, so always check the day as well as the hour.
Time difference between BST and Tehran Time
The time difference between BST and Tehran Time is not the same all year, because the two sides change for daylight saving time on different dates. In 2026 it works out like this:
- 1 Jan 2026 – 28 Mar 2026: Tehran Time is 3 hours 30 minutes ahead of BST.
- 29 Mar 2026 – 24 Oct 2026: Tehran Time is 2 hours 30 minutes ahead of BST.
- 25 Oct 2026 – 31 Dec 2026: Tehran Time is 3 hours 30 minutes ahead of BST.
BST and Tehran Time during daylight saving time
- BST next changes on 28 Mar 2027: clocks go forward one hour at 00:59 local time, from GMT (UTC+0) to BST (UTC+1).
- Tehran Time does not observe daylight saving time; it stays on UTC+3:30 all year.
Best time for a meeting between BST and Tehran Time
BST and Tehran Time share 4 hours 30 minutes of the 9 AM–5 PM working day. Any time between 9:00 AM and 1:30 PM GMT lands between 12:30 PM and 5:00 PM IRST, inside working hours for both.
BST to Tehran Time FAQ
What is the time difference between BST and Tehran Time?
Right now IRST is 3 hours 30 minutes ahead of GMT. The gap changes 3 times in 2026 because the two sides switch to daylight saving time on different dates.
What is 9 AM BST in Tehran Time?
9:00 AM GMT is 12:30 PM IRST.
What is 12 PM (noon) BST in Tehran Time?
12:00 PM GMT is 3:30 PM IRST.
Is Tehran Time ahead of or behind BST?
IRST is 3 hours 30 minutes ahead of GMT, so it is later in Tehran Time than in BST.
Does BST change for daylight saving time?
Yes. BST next changes on 28 Mar 2027, when clocks go forward one hour from GMT to BST.
Does Tehran Time change for daylight saving time?
No. Tehran Time stays on the same offset all year, so conversions never shift for daylight saving time.
What is the best time for a meeting between BST and Tehran Time?
BST and Tehran Time share 4 hours 30 minutes of the 9 AM–5 PM working day. Any time between 9:00 AM and 1:30 PM GMT lands between 12:30 PM and 5:00 PM IRST, inside working hours for both.
Related conversions
Convert Tehran Time to BST
Convert BST to other time zones
Convert other time zones to Tehran Time
Learn more
Updated 7 November 2026. Time zone data: IANA tz database.