Does Kolkata observe daylight saving time?

No. Kolkata stays on IST (UTC+5:30) all year, so its clocks don't change.

Does London observe daylight saving time?

Yes. London is on BST (UTC+1) now, and its clocks go back 1 hour on Sun, Oct 25, to GMT (UTC+0).

What time is it in London when it's 9 AM in Kolkata?

4:30 AM in London, on the same day.

Kolkata to London Meeting Planner

London is 4 hours 30 minutes behind Kolkata right now. Their working days overlap for 3 hours 30 minutes today.

Kolkata · India

6:10 PM

Sat, Oct 17 · IST

London · United Kingdom

1:40 PM

Sat, Oct 17 · BST · summer time

Best Meeting Times Between Kolkata and London

1:30 PM to 5:00 PM in Kolkata (9:00 AM to 12:30 PM in London). That's when both cities are inside working hours, 9 AM to 5 PM, giving 3 hours 30 minutes of overlap today.

Who's meeting

2 of 4 places

KolkataOrganizerIndia ·6:10PMnow
LondonUnited Kingdom ·· summer time1:40PMnow

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Date in Kolkata

Working hours, everywhere

Best times to meet

Saturday, October 17, 2026, in Kolkata time.

1:30PMBest · OptimalWorking hours in Kolkata (13:30) and London (09:00).
2:00PMOption 2 · OptimalWorking hours in Kolkata (14:00) and London (09:30).
2:30PMOption 3 · OptimalWorking hours in Kolkata (14:30) and London (10:00).

The whole day

Pick any slot in the Fit row, or use the arrow keys there, to make it the meeting time.

Each column is a half hour of the first place's day. The Fit row grades how well the slot suits everyone; each row shows the local time and whether it's working hours there.
Fit
KolkataIST
LondonBST
UTC	19	20	21	22	23	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18

Working hours (09–17)Just outside (07–09, 17–20)Late evening (20–23)NightFit: optimal, good, possible, poor

Your meeting

Kolkata1:30 PM ISTSat, Oct 17
London9:00 AM BSTSat, Oct 17
UTC2026-10-17 08:00 UTC

What will it cost? Try the meeting cost calculator.

Time difference between Kolkata and London

London is 4 hours 30 minutes behind Kolkata right now: London is on BST (UTC+1) and Kolkata on IST (UTC+5:30). That changes on Sun, Oct 25, when clocks go back in London: then London is 5 hours 30 minutes behind Kolkata.

Time difference between Kolkata and London over the next 12 months
From	Difference	Why
Now	London 4 hours 30 minutes behind	—
Sun, Oct 25	London 5 hours 30 minutes behind	Clocks go back in London
Sun, Mar 28, 2027	London 4 hours 30 minutes behind	Clocks go forward in London

Kolkata is on India Standard Time. London is on Greenwich Mean Time.

Frequently Asked Questions: Kolkata & London Scheduling

What is the time difference between Kolkata and London?: London is 4 hours 30 minutes behind Kolkata right now: London is on BST (UTC+1) and Kolkata on IST (UTC+5:30). That changes on Sun, Oct 25, when clocks go back in London: then London is 5 hours 30 minutes behind Kolkata.
What is the best time to schedule a meeting between Kolkata and London?: 1:30 PM to 5:00 PM in Kolkata (9:00 AM to 12:30 PM in London). That's when both cities are inside working hours, 9 AM to 5 PM, giving 3 hours 30 minutes of overlap today.
Does Kolkata observe daylight saving time?: No. Kolkata stays on IST (UTC+5:30) all year, so its clocks don't change.
Does London observe daylight saving time?: Yes. London is on BST (UTC+1) now, and its clocks go back 1 hour on Sun, Oct 25, to GMT (UTC+0).
What time is it in London when it's 9 AM in Kolkata?: 4:30 AM in London, on the same day.

Or see every city pair, or plan with more places in the meeting planner.