IST to GMT Converter

India Standard Time → Greenwich Mean Time · IST is 5.5 hours ahead of GMT

IST
—
GMT
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IST and GMT are the same time

IST to GMT Conversion Table

ISTGMT
12:00 AM12:00 AM
1:00 AM1:00 AM
2:00 AM2:00 AM
3:00 AM3:00 AM
4:00 AM4:00 AM
5:00 AM5:00 AM
6:00 AM6:00 AM
7:00 AM7:00 AM
8:00 AM8:00 AM
9:00 AM9:00 AM
10:00 AM10:00 AM
11:00 AM11:00 AM
12:00 PM12:00 PM
1:00 PM1:00 PM
2:00 PM2:00 PM
3:00 PM3:00 PM
4:00 PM4:00 PM
5:00 PM5:00 PM
6:00 PM6:00 PM
7:00 PM7:00 PM
8:00 PM8:00 PM
9:00 PM9:00 PM
10:00 PM10:00 PM
11:00 PM11:00 PM

Green rows = business hours overlap (9:00 AM – 6:00 PM IST)

Major IST Cities
  • Mumbai
  • Delhi
  • Bangalore
  • Hyderabad
  • Chennai
  • Kolkata
Major GMT Cities
  • London, UK
  • Birmingham, UK
  • Manchester, UK
  • Edinburgh, UK
  • Dublin, Ireland
  • Cardiff, UK
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IST vs GMT — What You Need to Know

India Standard Time (IST) is UTC+5:30. India does not observe DST, making IST one of the world's most consistent time zones.

Greenwich Mean Time (GMT) is UTC+0. The UK observes British Summer Time (BST, UTC+1) from late March to late October.

With only a 5.5-hour gap, India and the UK have reasonable scheduling options. The business hours overlap window is approximately 1:30–5:30 PM IST = 8:00 AM–12:00 PM GMT. This window shifts to 12:30–4:30 PM IST during BST (since BST is UTC+1).

Note on DST shift:

During UK BST (late March to late October), the gap narrows: 5.5h → 4.5h. India stays at UTC+5:30 year-round, but the UK moves to UTC+1.

Frequently Asked Questions

How many hours ahead is IST compared to GMT?

IST (UTC+5:30) is 5 hours 30 minutes (5.5h) ahead of GMT (UTC+0), and 4 hours 30 minutes (4.5h) ahead of BST (UTC+1) during UK summer time.

When it is 9:00 AM GMT, what time is it in India?

When it is 9:00 AM GMT, it is 2:30 PM IST. During BST (UK summer), 9:00 AM BST = 1:30 PM IST.

What is the best time for a call between India and the UK?

The best overlap is 1:30–5:30 PM IST = 8:00 AM–12:00 PM GMT. During BST, the window is 12:30–4:30 PM IST = 8:00 AM–12:00 PM BST. Both parties are in standard business hours during this window.

Why does India have a 30-minute offset from whole UTC hours?

India uses UTC+5:30 to reflect the geographic midpoint of the country. This is a compromise between UTC+5 (western India) and UTC+6 (eastern India), established at independence in 1947.