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

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

IST to GMT Time Converter

India Standard Time → Greenwich Mean Time

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

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

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

ClockinSync

BASE

09:00

Work Clients Team +

00:0006:0012:0018:0024:00

GMT (London)

United Kingdom · -4.5h🔔 Public Holiday in 1d — World Cup Bank Holiday

04:30

New York

USA · -9.5h

23:30-1 day

Tokyo

Japan · +3.5h

12:30

Dubai

United Arab Emirates · -1.5h

07:30

Sydney

Australia · +4.5h

13:30

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

IST (Mumbai) is 4 hours 30 minutes ahead of GMT (London). Midday in IST (Mumbai) lines up with 07:00 in GMT (London).

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

Daily overlap window

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

00:0006:0012:0018:0024:00

IST (Mumbai)

GMT (London)

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.

14:00 Mumbai / 09:00 London✓ Both working

15:00 Mumbai / 10:00 London✓ Both working

16:00 Mumbai / 11:00 London✓ Both working

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

Upcoming public holidays

IST (Mumbai)

No upcoming public holidays this year.

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

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

The 4.5-hour gap between IST (Mumbai) (India) and GMT (London) (United Kingdom) 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 IST (Mumbai), aim for 14:00–15:00, which corresponds to 09:00–10:00 in GMT (London) — both teams are within working hours.

✅

If you are in IST (Mumbai), aim for 15:00–16:00, which corresponds to 10:00–11:00 in GMT (London) — both teams are within working hours.

✅

If you are in IST (Mumbai), aim for 16:00–17:00, which corresponds to 11:00–12:00 in GMT (London) — 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 IST (Mumbai)".

IST (Mumbai) ↔ GMT (London)

3h of business hours overlap daily (09:00–17:00)

IST (Mumbai)

GMT (London)