GMT to IST Converter
IST is 5 hours 30 minutes ahead of GMT. During UK BST (summer), the gap narrows to 4 hours 30 minutes. 9:00 AM in London is 2:30 PM in India on GMT and 1:30 PM on BST.
GMT to IST, Every Hour
Full 24-hour reference table. Use the live clocks above for the exact current offset.
| 🇬🇧 GMT/BST | 🇮🇳 GMT → ISTUTC+0 to UTC+5:30 | 🇮🇳 BST → ISTUTC+1 to UTC+5:30 |
|---|---|---|
| 00:00 | 5:30 AM | 4:30 AM |
| 01:00 | 6:30 AM | 5:30 AM |
| 02:00 | 7:30 AM | 6:30 AM |
| 03:00 | 8:30 AM | 7:30 AM |
| 04:00 | 9:30 AM | 8:30 AM |
| 05:00 | 10:30 AM | 9:30 AM |
| 06:00 | 11:30 AM | 10:30 AM |
| 07:00 | 12:30 PM | 11:30 AM |
| 08:00 | 1:30 PM | 12:30 PM |
| 09:00 | 2:30 PM | 1:30 PM |
| 10:00 | 3:30 PM | 2:30 PM |
| 11:00 | 4:30 PM | 3:30 PM |
| 12:00 | 5:30 PM | 4:30 PM |
| 13:00 | 6:30 PM | 5:30 PM |
| 14:00 | 7:30 PM | 6:30 PM |
| 15:00 | 8:30 PM | 7:30 PM |
| 16:00 | 9:30 PM | 8:30 PM |
| 17:00 | 10:30 PM | 9:30 PM |
| 18:00 | 11:30 PM | 10:30 PM |
| 19:00 | 12:30 AMnext day | 11:30 PM |
| 20:00 | 1:30 AMnext day | 12:30 AMnext day |
| 21:00 | 2:30 AMnext day | 1:30 AMnext day |
| 22:00 | 3:30 AMnext day | 2:30 AMnext day |
| 23:00 | 4:30 AMnext day | 3:30 AMnext day |
* "next day" = converted time falls on the following calendar day.
The UK Morning Is the India Afternoon
With 9-to-5 days on both sides, the window sits in the London morning. On GMT it runs from 9:00 to 11:30 AM in London (2:30 PM to 5:00 PM in India), 2 hours 30 minutes. On BST it runs from 9:00 AM to 12:30 PM (1:30 PM to 5:00 PM in India), 3 hours 30 minutes. India's 5 PM close ends it in both seasons, so a London call after 11:30 AM in winter reaches India after hours.
| Greenwich Mean Time | India Standard Time |
|---|---|
| 9:00 AM–11:30 AM | 2:30 PM–5:00 PM |
| GMT → IST: Both inside 9 AM–5 PM Winter: the London morning meets the India afternoon until India closes. | |
| 9:00 AM–12:30 PM | 1:30 PM–5:00 PM |
| BST → IST: Both inside 9 AM–5 PM Summer: an hour longer, because London is an hour closer. | |
"Inside 9 AM–5 PM" is a planning assumption for a standard office day on each side, not a claim about any company's hours.
Which London Hours Reach India's Working Day
Each row is an hour of the London day with the India time next to it. A check mark means both cities are inside a 9-to-5 day, which happens from 9:00 to 11:00 AM on GMT and from 9:00 AM to 12:00 PM on BST.
| Greenwich Mean Time | India Standard Time (GMT → IST) | India Standard Time (BST → IST) |
|---|---|---|
| 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 |
Each row is an hour of the Greenwich Mean Time day. A check mark means both cities are inside a 9 AM to 5 PM working day at that moment.
- GMT → IST: 2 hours 30 minutes shared, 9:00 AM to 11:30 AM Greenwich Mean Time time.
- BST → IST: 3 hours 30 minutes shared, 9:00 AM to 12:30 PM Greenwich Mean Time time.
GMT Is Only the UK in Winter
Greenwich Mean Time (GMT, UTC+0) is the UK's winter time. From the last Sunday in March to the last Sunday in October the UK is on BST (UTC+1), which narrows the gap with India by an hour. India is on IST (UTC+5:30) all year and never changes its clocks, so the half hour always carries into the conversion: 9:00 AM GMT is 2:30 PM IST, and 9:00 AM BST is 1:30 PM IST.
Going the other way, India's 3:00 PM is 9:30 AM in London on GMT and 10:30 AM on BST. If you fix a meeting in India time, it moves by an hour on the London clock in March and October; quote both times in the invite.
A London Late-Morning Call With India
An 11:00 AM start in London reaches 4:30 PM in India while the UK is on GMT, and 3:30 PM once the UK is on BST. A 10:00 AM start is 3:30 PM on GMT and 2:30 PM on BST.
Work backward from India's 5:00 PM close. For a one-hour call that has to finish by then, the latest start is 4:00 PM in India, which is 10:30 AM in London on GMT and 11:30 AM on BST. A call that begins at noon in London is already 5:30 PM in India on GMT, after the working day has ended.
India doesn't change its clocks, so every change comes from the UK side. After the last Sunday in March a call that stays at the same London time moves an hour earlier on India's clock. Mention the change in the invite so the India team isn't surprised.