BST to IST converter
UK time (British Summer Time) to India Standard Time. IST is 5 h 30 min ahead of BST in January and 4 h 30 min ahead in July.
From
BST · London GMT+1 · UTC+1
- IST · KolkataUTC+5:30 · 4 h 30 min ahead13:30Mon, Sep 28
The gap between BST and IST
| 2026 | BST clocks | IST clocks | Difference |
|---|---|---|---|
| January | GMT UTC+0 | GMT+5:30 UTC+5:30 | 5 h 30 min ahead |
| July | GMT+1 UTC+1 | GMT+5:30 UTC+5:30 | 4 h 30 min ahead |
The gap changes on: Sun, March 29, 2026 (4 h 30 min ahead); Sun, October 25, 2026 (5 h 30 min ahead); Sun, March 28, 2027 (4 h 30 min ahead); Sun, October 31, 2027 (5 h 30 min ahead).
BST to IST time table
Every hour of the BST day and the matching IST time, for a mid-January and a mid-July date.
| BST | IST · January | IST · July |
|---|---|---|
| 12:00 AM | 5:30 AM | 4:30 AM |
| 1:00 AM | 6:30 AM | 5:30 AM |
| 2:00 AM | 7:30 AM | 6:30 AM |
| 3:00 AM | 8:30 AM | 7:30 AM |
| 4:00 AM | 9:30 AM | 8:30 AM |
| 5:00 AM | 10:30 AM | 9:30 AM |
| 6:00 AM | 11:30 AM | 10:30 AM |
| 7:00 AM | 12:30 PM | 11:30 AM |
| 8:00 AM | 1:30 PM | 12:30 PM |
| 9:00 AM | 2:30 PM | 1:30 PM |
| 10:00 AM | 3:30 PM | 2:30 PM |
| 11:00 AM | 4:30 PM | 3:30 PM |
| 12:00 PM | 5:30 PM | 4:30 PM |
| 1:00 PM | 6:30 PM | 5:30 PM |
| 2:00 PM | 7:30 PM | 6:30 PM |
| 3:00 PM | 8:30 PM | 7:30 PM |
| 4:00 PM | 9:30 PM | 8:30 PM |
| 5:00 PM | 10:30 PM | 9:30 PM |
| 6:00 PM | 11:30 PM | 10:30 PM |
| 7:00 PM | 12:30 AM (+1 day) | 11:30 PM |
| 8:00 PM | 1:30 AM (+1 day) | 12:30 AM (+1 day) |
| 9:00 PM | 2:30 AM (+1 day) | 1:30 AM (+1 day) |
| 10:00 PM | 3:30 AM (+1 day) | 2:30 AM (+1 day) |
| 11:00 PM | 4:30 AM (+1 day) | 3:30 AM (+1 day) |
About these two clocks
BST — UK time (British Summer Time). Used in London, Manchester, Edinburgh. BST is the UK summer clock (UTC+1). In winter UK clocks fall back to GMT; this page follows London clocks for the date you choose.
IST — India Standard Time. Used in all of India — Mumbai, Delhi, Bengaluru. India does not use daylight saving time, so IST is UTC+5:30 all year.
All figures on this page come from the IANA time zone database (the same data your phone and laptop use), evaluated for the date in question. Abbreviations are ambiguous — “IST” also means Irish or Israel Standard Time, and “CST” is China Standard Time in Asia — so this page uses Europe/London and Asia/Kolkata explicitly.
Questions people ask
How many hours ahead or behind is IST compared with BST?
IST is 5 h 30 min ahead of BST in January and 4 h 30 min ahead in July. The gap moves because daylight saving time starts and ends on different dates (or not at all) in the two places.
What is 9 am BST in IST?
On a January date, 9:00 am BST is 2:30 PM IST. In July it is 1:30 PM. Use the converter above for any other date.
Which cities use BST?
UK time (British Summer Time) (BST) is used in London, Manchester, Edinburgh. BST is the UK summer clock (UTC+1). In winter UK clocks fall back to GMT; this page follows London clocks for the date you choose.
Which cities use IST?
India Standard Time (IST) is used in all of India — Mumbai, Delhi, Bengaluru. India does not use daylight saving time, so IST is UTC+5:30 all year.
When is a good time for a BST–IST call?
Look for the hours where both columns in the table fall between about 8 am and 6 pm. If none exist, the meeting planner on our home page shows the least-bad options and lets you share a link that converts for every attendee.
Related conversions
EST to ISTUTC to ISTCST to ISTPST to ISTCET to ISTGMT to ISTSGT to ISTBST to ESTAEST to ISTJST to IST