GMT vs IST
Greenwich Mean Time / UK (GMT/BST) is UTC+0 in winter and UTC+1 in summer. India Standard Time (IST) is UTC+5:30 year-round.
Because Greenwich Mean Time / UK observes daylight saving and the other zone does not, the gap changes during the year: 5.5 hours ahead in the northern winter and 4.5 hours ahead in summer, with a few weeks in spring and autumn where it's an hour different again. The converter uses the exact rules for the date you choose.
GMT to IST conversion table
Summer (daylight saving) times, mid-July:
| GMT/BST | IST |
|---|---|
| 12:00 AM | 4:30 AM |
| 6:00 AM | 10:30 AM |
| 8:00 AM | 12:30 PM |
| 9:00 AM | 1:30 PM |
| 10:00 AM | 2:30 PM |
| 12:00 PM | 4:30 PM |
| 2:00 PM | 6:30 PM |
| 3:00 PM | 7:30 PM |
| 5:00 PM | 9:30 PM |
| 6:00 PM | 10:30 PM |
| 8:00 PM | 12:30 AM (+1 day) |
| 10:00 PM | 2:30 AM (+1 day) |
Winter (standard) times, mid-January:
| GMT | IST |
|---|---|
| 12:00 AM | 5:30 AM |
| 6:00 AM | 11:30 AM |
| 8:00 AM | 1:30 PM |
| 9:00 AM | 2:30 PM |
| 10:00 AM | 3:30 PM |
| 12:00 PM | 5:30 PM |
| 2:00 PM | 7:30 PM |
| 3:00 PM | 8:30 PM |
| 5:00 PM | 10:30 PM |
| 6:00 PM | 11:30 PM |
| 8:00 PM | 1:30 AM (+1 day) |
| 10:00 PM | 3:30 AM (+1 day) |
Scheduling between GMT and IST
The working-day overlap is a few hours: morning in the zone that's behind matches afternoon in the zone that's ahead. For example, 9 AM GMT is 1:30 PM IST. Always write the city alongside the abbreviation in invites — several abbreviations (CST, IST, AST) are used by more than one region.
Related conversions
GMT to EST · EST to GMT · GMT to PST · PST to GMT · GMT to CST · CST to GMT · EST to IST · IST to EST · PST to IST · IST to PST · all zones