Greenwich Mean Time (gmt) is used in United Kingdom. The IANA timezone identifier is Europe/London.

India Standard Time (ist) is used in India. The IANA timezone identifier is Asia/Kolkata.

GMT to IST Time Converter

Greenwich Mean Time → India Standard Time

GMT = UTC+1IST = UTC+5:30

⚠️ IST is ambiguous — on this page it means India Standard Time. It also refers to:

GMT → Ireland Standard Time (Dublin) ↗GMT → Israel Standard Time (Jerusalem) ↗

ClockinSync

BASE

09:00

Work Clients Team +

00:0006:0012:0018:0024:00

IST (Mumbai)

India · +4.5h

13:30

New York

USA · -5h

04:00

Tokyo

Japan · +8h

17:00

Dubai

United Arab Emirates · +3h

12:00

Sydney

Australia · +9h

18:00

How far apart are GMT (London) and IST (Mumbai)?

GMT (London) is 5 hours 30 minutes behind IST (Mumbai). Midday in GMT (London) lines up with 16:00 in IST (Mumbai).

GMT (London) runs on Europe/London; IST (Mumbai) runs on Asia/Kolkata. Together they are 4.5 hours 30 minutes apart.

Daily overlap window

There is a 3.5-hour window each day where both GMT (London) and IST (Mumbai) are within standard business hours (09:00–17:00).

00:0006:0012:0018:0024:00

GMT (London)

IST (Mumbai)

Overlap (3.5h)

Best times to schedule a meeting

There is a 3.5-hour daily window where both locations are in business hours. The 3 best slots are listed below.

09:00 London / 13:00 Mumbai✓ Both working

10:00 London / 14:00 Mumbai✓ Both working

11:00 London / 15:00 Mumbai✓ Both working

Working hours defined as 09:00–17:00 local time for each location.

Upcoming public holidays

GMT (London)7 holidays

Jun 15World Cup Bank HolidaySOON

Jul 13Battle of the Boyne

Aug 3Summer Bank Holiday

Aug 31Summer Bank Holiday

Nov 30Saint Andrew's Day

IST (Mumbai)

No upcoming public holidays this year.

How to work with GMT (London) and IST (Mumbai) time zones

The 4.5-hour gap between GMT (London) (United Kingdom) and IST (Mumbai) (India) requires some planning — but a 3.5-hour daily overlap means both teams can connect in real time without unusual scheduling.

💡 How to schedule across these time zones

✅

If you are in GMT (London), aim for 09:00–10:00, which corresponds to 13:00–14:00 in IST (Mumbai) — both teams are within working hours.

✅

If you are in GMT (London), aim for 10:00–11:00, which corresponds to 14:00–15:00 in IST (Mumbai) — both teams are within working hours.

✅

If you are in GMT (London), aim for 11:00–12:00, which corresponds to 15:00–16:00 in IST (Mumbai) — both teams are within working hours.

Avoid scheduling mistakes — especially around daylight saving changes. Use the ClockinSync Chrome Extension to instantly verify and compare both time zones directly in your browser, without manual calculations.

Add to your browser — Free →

Need a specific time? Use the slider or type directly into the input bar — it understands "3pm", "15:30", and location-specific formats like "9am GMT (London)".

GMT (London) ↔ IST (Mumbai)

4h of business hours overlap daily (09:00–17:00)

GMT (London)

IST (Mumbai)

00:00

04:30

01:00

05:30

02:00

06:30

03:00

07:30

04:00

08:30

05:00

09:30Working

06:00

10:30Working

07:00

11:30Working

08:00

12:30Working

09:00Working

13:30Working

10:00Working

14:30Working

11:00Working

15:30Working

12:00Working

16:30Working

13:00Working

17:30off

14:00Working

18:30off

15:00Working

19:30off

16:00Working

20:30off

17:00

21:30

18:00

22:30

19:00

23:30

20:00

00:30+1d

21:00

01:30+1d

22:00

02:30+1d

23:00

03:30+1d

Working hours: 09:00–17:00 local. Green = both working. Purple = one side only.

Frequently Asked Questions

What is the difference between gmt and ist?

Greenwich Mean Time (gmt) is UTC+1 and India Standard Time (ist) is UTC+5:30. The difference between them is 4.5 hours.

Where is gmt used?

Greenwich Mean Time (gmt) is used in United Kingdom and surrounding regions. The IANA timezone identifier is Europe/London.

Where is ist used?

India Standard Time (ist) is used in India and surrounding regions. The IANA timezone identifier is Asia/Kolkata. Note: ist is ambiguous and may refer to other timezones.

How do I convert gmt to ist?

Use the interactive converter above. Drag the time slider to any gmt time and the ist equivalent updates instantly. You can also type a time like "3pm" or "15:00" in the input bar.

Popular GMT conversions

GMT → New York GMT → Tokyo GMT → Dubai GMT → Sydney GMT → Paris GMT → Berlin GMT → Singapore GMT → Los Angeles GMT → Toronto GMT → Mumbai

Popular IST conversions

London → IST New York → IST Tokyo → IST Dubai → IST Sydney → IST Paris → IST Berlin → IST Singapore → IST Los Angeles → IST Toronto → IST