How many hours is IST ahead of WEST?
As abbreviations, WEST is always 4.5 hours behind of IST: IST is UTC+5:30 and WEST is UTC+1. To convert, subtract 4.5 hours.
When the IST to WEST time difference changes
For most of the year WEST is 4.5 hours behind of IST. From 25 October to 31 December 2026, WEST is 5.5 hours behind of IST instead, because the two places change their clocks on different dates. Meetings booked by the usual gap land an hour off in those weeks.
| Dates | WEST vs IST | Length |
|---|---|---|
| 29 March 2026 to 24 October 2026 | 4.5 hours behind | 210 days |
| 25 October 2026 to 31 December 2026 | 5.5 hours behind | 68 days |
| 1 January 2027 to 27 March 2027 | 5.5 hours behind | 86 days |
| 28 March 2027 to 30 October 2027 | 4.5 hours behind | 217 days |
| 31 October 2027 to 31 December 2027 | 5.5 hours behind | 62 days |
Best time for a meeting between IST and WEST
- When WEST is 4.5 hours behind of IST: 3 shared office hours, 14:00 to 17:00 in IST (09:30 to 12:30 in WEST).
- When WEST is 5.5 hours behind of IST: 2 shared office hours, 15:00 to 17:00 in IST (09:30 to 11:30 in WEST).