Timezone conversion
IST to GMT/BST
Convert India Standard Time (IST) to Greenwich Mean Time (GMT/BST). Daylight-saving adjustments are applied automatically.
Conversion table
Common times in IST and their equivalents in GMT/BST:
| IST | GMT/BST |
|---|---|
| 12:00 AM | 6:30 PMWed |
| 3:00 AM | 9:30 PMWed |
| 6:00 AM | 12:30 AM |
| 9:00 AM | 3:30 AM |
| 12:00 PM | 6:30 AM |
| 3:00 PM | 9:30 AM |
| 6:00 PM | 12:30 PM |
| 9:00 PM | 3:30 PM |
Table computed using a fixed reference date to keep output stable. Use the full converter for any date and time.
Common meeting times
Quick translations for typical business hours in India Standard Time:
- 9:00 AM IST3:30 AM GMT/BST
- 12:00 PM IST6:30 AM GMT/BST
- 3:00 PM IST9:30 AM GMT/BST
- 5:00 PM IST11:30 AM GMT/BST
Best time to schedule a call
The ideal window where both IST and GMT/BST are inside business hours (08:00–18:00) is 1:30 PM–6:00 PM IST, which is 8:00 AM–12:30 PM GMT/BST.
Upcoming offset transitions
At least one of these zones observes DST. The hours-apart number changes on the following dates over the next 12 months:
- Mar 30, 2026 — gap becomes -4.5h
- Oct 26, 2026 — gap becomes -5.5h
Sample calendar invite
Copy-paste this into your calendar event so attendees see both zones spelled out.
Subject: Sync meeting Time: 10:00 AM IST (India Standard Time) = 4:30 AM GMT/BST (Greenwich Mean Time) Date: Thursday, 15 January 2026 Notes: India Standard Time ↔ Greenwich Mean Time conversion handled with DST applied automatically.
About India Standard Time and Greenwich Mean Time
India Standard Time
Zone: Asia/Kolkata
Abbreviation: IST
Greenwich Mean Time
Zone: Europe/London
Abbreviation: GMT/BST
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Frequently asked questions
- What time is it in Greenwich Mean Time when it's noon in India Standard Time?
- When it's 12:00 PM IST, it's 6:30 AM GMT/BST.
- What's the best time to schedule a call between IST and GMT/BST?
- Business-hour overlap (08:00–18:00 in both zones) lands at 1:30 PM–6:00 PM IST, which is 8:00 AM–12:30 PM GMT/BST. Schedule inside that window for both sides to be in their working day.
- Does the time difference between IST and GMT/BST change during the year?
- Yes — at least one zone observes daylight saving time, so the gap shifts during the year. Upcoming transitions: Mar 30, 2026, Oct 26, 2026.
- Does this converter handle daylight saving time?
- Yes. All calculations use the IANA time zone database (via Luxon), so DST transitions for both India Standard Time and Greenwich Mean Time are applied automatically.
Need something else? Convert any time between any two zones →