Live IST to UK Time Converter
India Standard Time (IST) is fixed at UTC+5:30. The UK uses two time zones each year:
- Greenwich Mean Time (GMT): UTC+0, used roughly late October to late March
- British Summer Time (BST): UTC+1, used roughly late March to late October
Because India does not observe daylight saving, the difference between IST and UK time shrinks by one hour when the UK moves to BST.
IST to GMT (Winter)
When the UK is on GMT (winter), London is 5 hours 30 minutes behind New Delhi.
| India (IST) | UK (GMT) |
|---|---|
| 06:00 | 00:30 (previous day) |
| 09:00 | 03:30 |
| 12:00 | 06:30 |
| 15:00 | 09:30 |
| 18:00 | 12:30 |
| 21:00 | 15:30 |
| 00:00 (next day) | 18:30 |
A 09:00 meeting in Delhi is 03:30 in London. A 15:00 call from London reaches Delhi at 20:30.
IST to BST (Summer)
When the UK is on BST (summer), London is 4 hours 30 minutes behind New Delhi.
| India (IST) | UK (BST) |
|---|---|
| 06:00 | 01:30 |
| 09:00 | 04:30 |
| 12:00 | 07:30 |
| 15:00 | 10:30 |
| 18:00 | 13:30 |
| 21:00 | 16:30 |
| 00:00 (next day) | 19:30 |
A 09:00 meeting in Delhi is 04:30 in London. A 15:00 call from London reaches Delhi at 19:30.
How UK Clock Changes Affect the Gap
The UK shifts clocks twice a year. India stays on UTC+5:30 the whole time.
- Late March: UK goes from GMT to BST. The gap narrows from 5:30 to 4:30 overnight. A 09:00 Delhi meeting was 03:30 in London on Sunday; on Monday it is 04:30.
- Late October: UK goes from BST back to GMT. The gap widens from 4:30 back to 5:30. Same 09:00 Delhi meeting shifts from 04:30 to 03:30 in London.
Common mistake: using +5:30 to London in July. In summer the correct offset is +4:30. A call scheduled for 10:00 London time using the winter gap would ring in Delhi at 15:30 instead of 14:30, a one-hour miss.
The next change is late March 2027, when the UK moves to BST and the gap narrows to 4 hours 30 minutes. If you schedule recurring meetings, update the start time or your calendar tool will keep the old offset.
Quick Reference: IST to UK Time at a Glance
| Season | UK time zone | Offset from IST | What that means |
|---|---|---|---|
| Late October to late March | GMT (UTC+0) | IST is 5h 30m ahead | Delhi 12:00 = London 06:30 |
| Late March to late October | BST (UTC+1) | IST is 4h 30m ahead | Delhi 12:00 = London 07:30 |
India is always ahead. The UK never catches up.
For calling tips and meeting windows, see the Best Time to Call India From the UK guide. For the full explanation of why the offset is half an hour, read Why Is India's Time Zone Half an Hour Off?.