London to Kolkata (Calcutta): time difference
Kolkata (Calcutta) is 4 h 30 min ahead of London. Live clocks for both, the working hours they share, and how each one sits against your own time.
🇮🇳 Kolkata (Calcutta), India
40
- India Standard Time
- UTC+5:30
- Twilight
☀️ 05:32 · 🌙 17:17 · 11 h 46 min
+4 h 30 min
Your time
One day, 2 clocks
Drag along the band to read any hour in every place at once.
London 13:12 1:12 PM Kolkata (Calcutta) 17:42 5:42 PM You –:–
13:12 1:12 PM
British Summer Time · UTC+1
☀️ 07:16 · 🌙 18:20
17:42 5:42 PM
India Standard Time · UTC+5:30
☀️ 05:32 · 🌙 17:17
·
+4 h 30 min
Kolkata (Calcutta) is 4 h 30 min ahead of London.
When you, London and Kolkata (Calcutta) are all at the desk
Pick the working hours below – the window every location shares appears once your time zone is known.
Working hours
🇬🇧 London
0 12 AM 1 1 AM 2 2 AM 3 3 AM 4 4 AM 5 5 AM 6 6 AM 7 7 AM 8 8 AM 9 9 AM 10 10 AM 11 11 AM 12 12 PM 13 1 PM 14 2 PM 15 3 PM 16 4 PM 17 5 PM 18 6 PM 19 7 PM 20 8 PM 21 9 PM 22 10 PM 23 11 PM
🇮🇳 Kolkata (Calcutta)
4:30 4:30 AM 5:30 5:30 AM 6:30 6:30 AM 7:30 7:30 AM 8:30 8:30 AM 9:30 9:30 AM 10:30 10:30 AM 11:30 11:30 AM 12:30 12:30 PM 13:30 1:30 PM 14:30 2:30 PM 15:30 3:30 PM 16:30 4:30 PM 17:30 5:30 PM 18:30 6:30 PM 19:30 7:30 PM 20:30 8:30 PM 21:30 9:30 PM 22:30 10:30 PM 23:30 11:30 PM 0:30 12:30 AM 1:30 1:30 AM 2:30 2:30 AM 3:30 3:30 AM
📍 Your time
- Asleep
- Early
- Working hours
- Evening
- Both working
- Right now
Time zones side by side
| Detail | 🇬🇧 London | 🇮🇳 Kolkata (Calcutta) |
|---|---|---|
| Local time | 13:12 | 17:42 |
| Local date | Saturday, October 10, 2026 | Saturday, October 10, 2026 |
| Time zone | British Summer Time | India Standard Time |
| UTC offset | UTC+1 | UTC+5:30 |
| Offset from London | — | +4 h 30 min |
| IANA zone | Europe/London | Asia/Kolkata |
| Daylight saving | On summer time → UTC+0, Oct 25, 01:00 | Not observed |
| Sunrise | 07:16 | 05:32 |
| Sunset | 18:20 | 17:17 |
| Daylight | 11 h 4 min | 11 h 46 min |
| People on this clock | 8,908,083 | 4,486,679 |
Compare London with another city
More comparisons with London: the time zones next to it and the far side of the clock.
Big time differences
London and Kolkata (Calcutta): common questions
What is the time difference between London and Kolkata (Calcutta)?
Kolkata is 4 hours and 30 minutes ahead: it uses UTC+5:30, while London is on UTC+1.
If it is 9:00 AM in London, what time is it in Kolkata (Calcutta)?
At 9:00 AM in London, clocks in Kolkata show 1:30 PM.
What time is it in Kolkata (Calcutta) when it is 6:00 PM in London?
When it is 6:00 PM in London, it is 10:30 PM in Kolkata.
When is a good time to call Kolkata (Calcutta) from London?
Between 9:00 AM and 1:30 PM in London – that is 1:30 PM to 6:00 PM in Kolkata – both places are within working hours (9:00 AM–6:00 PM).
From what time in London is it tomorrow in Kolkata (Calcutta)?
Once it is 7:30 PM in London, the date in Kolkata has already changed. Until 4:30 AM in Kolkata, it is still the previous day in London.
Is the time difference between London and Kolkata (Calcutta) the same all year?
No. Only London switches to summer time, so the gap changes twice a year. From October 25, 2026, Kolkata will be 5 hours and 30 minutes ahead of London.
