GMT to IST
GMT is UTC+1 and IST is UTC+5:30 today — IST is 4½ hours ahead of GMT. Abbreviations are for reading: this page resolves GMT to Europe/London and IST to Asia/Kolkata, which are the names that do not go ambiguous.
GMT: London in winter; British Summer Time in summer. IST: India — Irish and Israel Standard Time share the letters.
The working day, side by side
Hours shaded in both rows are inside working hours on both sides. Current abbreviations: BST and IST.
| City | 00:00 in GMT | 01:00 in GMT | 02:00 in GMT | 03:00 in GMT | 04:00 in GMT | 05:00 in GMT | 06:00 in GMT | 07:00 in GMT | 08:00 in GMT | 09:00 in GMT | 10:00 in GMT | 11:00 in GMT | 12:00 in GMT | 13:00 in GMT | 14:00 in GMT | 15:00 in GMT | 16:00 in GMT | 17:00 in GMT | 18:00 in GMT | 19:00 in GMT | 20:00 in GMT | 21:00 in GMT | 22:00 in GMT | 23:00 in GMT |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GMT—— | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 |
| IST—— | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 |
- Working hours
- Shoulder
- Night
- Overlap
Do more with GMT and IST
Common questions
What is GMT in IST?
IST is 4½ hours ahead of GMT today: noon in GMT is 16:30 in IST.
Is GMT the same all year?
London in winter; British Summer Time in summer. An abbreviation describes an offset at a moment, not a place — the zone identifier Europe/London is the unambiguous name.
When can GMT and IST meet?
Working hours overlap for 4 hours a day: the shaded overlap is 14:00–18:00 in IST (09:00–13:00 your time).