Time difference
Kolkata to London Time Difference
London is 4 hours and 30 minutes behind Kolkata — when it's 12:00 PM in Kolkata, it's 7:30 AM in London. (Kolkata (Asia/Kolkata, IST); London (Europe/London, BST).) Below: live local times, the best hours for a call, a full conversion table, and exact daylight-saving dates.
London is 4 hours and 30 minutes behind Kolkata. The best window for a call is 1:30 PM–5 PM in Kolkata, which is 9 AM–12:30 PM in London — an overlap of 3 hours and 30 minutes inside 9 AM–5 PM on both sides. Clocks change on October 25, 2026, which briefly shifts the gap between Kolkata and London — the converter on this page always reflects the correct offset for the date you pick.
- When it's 9:00 AM in Kolkata, it's 4:30 AM in London.
- When it's 9:00 AM in London, it's 1:30 PM in Kolkata.
London is currently 4 hours and 30 minutes behind Kolkata.
Interactive converter
12:00PM
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Best times to meet
The 9 AM – 5 PM business windows in Kolkata and London overlap for 3 hours and 30 minutes. 1:30 PM–5 PM in Kolkata is 9 AM–12:30 PM in London. Aim somewhere in the middle of that window so neither side starts cold or finishes drained.
Quick conversion table
| Kolkata | London |
|---|---|
| 12 AM | 7:30 PM (prev day) |
| 1 AM | 8:30 PM (prev day) |
| 2 AM | 9:30 PM (prev day) |
| 3 AM | 10:30 PM (prev day) |
| 4 AM | 11:30 PM (prev day) |
| 5 AM | 12:30 AM |
| 6 AM | 1:30 AM |
| 7 AM | 2:30 AM |
| 8 AM | 3:30 AM |
| 9 AM | 4:30 AM |
| 10 AM | 5:30 AM |
| 11 AM | 6:30 AM |
| 12 PM | 7:30 AM |
| 1 PM | 8:30 AM |
| 2 PM | 9:30 AM |
| 3 PM | 10:30 AM |
| 4 PM | 11:30 AM |
| 5 PM | 12:30 PM |
| 6 PM | 1:30 PM |
| 7 PM | 2:30 PM |
| 8 PM | 3:30 PM |
| 9 PM | 4:30 PM |
| 10 PM | 5:30 PM |
| 11 PM | 6:30 PM |
Daylight saving
On October 25, 2026, London shifts for daylight saving. After that, London will be 5 hours and 30 minutes behind Kolkata (currently 4 hours and 30 minutes behind Kolkata). The converter and the tables above always reflect the correct offset for the date you pick.
- Kolkata does not observe daylight saving time.
- London is currently observing daylight saving time.
Frequently asked questions
- Is London ahead of or behind Kolkata?
- London is 4 hours and 30 minutes behind Kolkata.
- How many hours behind Kolkata is London?
- London is 4 hours and 30 minutes behind Kolkata.
- What time is 9 AM in Kolkata in London?
- 9:00 AM in Kolkata is 4:30 AM in London.
- What time is noon in Kolkata in London?
- 12:00 PM in Kolkata is 7:30 AM in London.
- What time is 5 PM in Kolkata in London?
- 5:00 PM in Kolkata is 12:30 PM in London. Useful for end-of-day handoffs between the two offices.
- What time is 3 PM in Kolkata in London?
- 3:00 PM in Kolkata is 10:30 AM in London.
- Is Kolkata currently observing daylight saving time?
- Kolkata does not observe daylight saving time — its UTC offset stays the same all year.
- Is London currently observing daylight saving time?
- London is currently observing daylight saving time (summer time).
- Do Kolkata and London observe daylight saving?
- On October 25, 2026, London shifts for daylight saving. After that, London will be 5 hours and 30 minutes behind Kolkata (currently 4 hours and 30 minutes behind Kolkata). The converter and the tables above always reflect the correct offset for the date you pick.
- When is the best time to call London from Kolkata?
- Aim for 1:30 PM–5 PM in Kolkata, which is 9 AM–12:30 PM in London.
- When is the best time to call Kolkata from London?
- Aim for 9 AM–12:30 PM in London, which is 1:30 PM–5 PM in Kolkata.
- Kolkata (IST) to London (BST) — how do I convert quickly?
- Subtract 4 hours and 30 minutes from Kolkata local time to get London local time. Or use the converter at the top of this page — it stays accurate through daylight-saving changes automatically.
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