This IST to GMT converter turns any time in India Standard Time (IST) into Greenwich Mean Time (GMT), using your device clock so daylight saving is applied automatically. GMT is 5 hours 30 minutes behind IST when both zones are on standard time, and 4 hours 30 minutes behind during the summer months when clocks have shifted. IST is UTC+5:30; GMT is UTC+0 (BST: UTC+1).
IST covers Mumbai, Delhi, Bengaluru; GMT covers London, Edinburgh, Dublin (IST). Because only GMT observes daylight saving time, the difference is not constant through the year. The tables below show both cases, and the converter at the top always uses the rule in force on the date you pick.
IST and GMT UTC offsets
IST
UTC+5:30
India Standard Time
No daylight saving time
GMT
UTC+0
Greenwich Mean Time
BST UTC+1 from March 29 to October 25, 2026
IST to GMT conversion table (standard time)
| IST | GMT |
|---|---|
| 12 am | 6:30 pmprevious day |
| 3 am | 9:30 pmprevious day |
| 6 am | 12:30 am |
| 8 am | 2:30 am |
| 9 am | 3:30 am |
| 10 am | 4:30 am |
| 11 am | 5:30 am |
| 12 pm | 6:30 am |
| 1 pm | 7:30 am |
| 2 pm | 8:30 am |
| 3 pm | 9:30 am |
| 4 pm | 10:30 am |
| 5 pm | 11:30 am |
| 6 pm | 12:30 pm |
| 8 pm | 2:30 pm |
| 10 pm | 4:30 pm |
IST to GMT during daylight saving
Between the dates listed above, the difference is 4 hours 30 minutes instead of 5 hours 30 minutes.
| IST | GMT/BST |
|---|---|
| 12 am | 7:30 pmprevious day |
| 3 am | 10:30 pmprevious day |
| 6 am | 1:30 am |
| 8 am | 3:30 am |
| 9 am | 4:30 am |
| 10 am | 5:30 am |
| 11 am | 6:30 am |
| 12 pm | 7:30 am |
| 1 pm | 8:30 am |
| 2 pm | 9:30 am |
| 3 pm | 10:30 am |
| 4 pm | 11:30 am |
| 5 pm | 12:30 pm |
| 6 pm | 1:30 pm |
| 8 pm | 3:30 pm |
| 10 pm | 5:30 pm |
Frequently asked questions
What is the time difference between IST and GMT?
GMT is 5 hours 30 minutes behind IST on standard time. During daylight saving the gap changes to 4 hours 30 minutes. That comes from the UTC offsets: IST is UTC+5:30 and GMT is UTC+0. For example, 9 am IST = 3:30 am GMT, and in summer 9 am IST = 4:30 am GMT.
Is GMT ahead of or behind IST?
GMT is 5 hours 30 minutes behind IST, so when it is noon in IST it is 6:30 am in GMT. Ahead means the clock there already shows a later time; a call at 5 pm IST lands at 11:30 am GMT.
Does IST or GMT observe daylight saving time in 2026?
IST keeps UTC+5:30 all year. GMT switches to BST (UTC+1) on March 29 and back on October 25. Between those dates the difference in the table above shifts by an hour, which is the usual cause of missed calls in spring and autumn.
What is the best time for a meeting between IST and GMT?
Standard office hours (9 am to 5 pm) overlap from 2.5 pm to 5 pm IST, which is 9 am to 11.5 am GMT. Pick a slot inside that window and both sides stay within a normal working day. Check the daylight saving dates above, because the window moves by an hour when only one side has changed clocks.
Which cities use IST and GMT?
IST (India Standard Time) is used in Mumbai, Delhi, Bengaluru, Kolkata. GMT (Greenwich Mean Time) is used in London, Edinburgh, Dublin (IST). Some cities inside a zone skip daylight saving, noted in parentheses, so their offset matches only part of the year.