The time difference between Kolkata and London is 4 hours and 30 minutes. When it is 12:00 noon in Kolkata, it is 07:30 in London. Kolkata uses the Asia/Kolkata time zone (UTC+5:30), while London uses Europe/London (UTC+1).
There are 3 overlapping business hours between Kolkata and London (assuming 9:00–17:00 in each city). The ideal window for calls and meetings is:
Use this table to quickly convert any hour from Kolkata time to London time. Rows highlighted in green indicate overlapping business hours in both cities.
| Kolkata | London | |
|---|---|---|
| 00:00 | 19:30 (-1 day) | Night |
| 01:00 | 20:30 (-1 day) | Night |
| 02:00 | 21:30 (-1 day) | Night |
| 03:00 | 22:30 (-1 day) | Night |
| 04:00 | 23:30 (-1 day) | Night |
| 05:00 | 00:30 | Night |
| 06:00 | 01:30 | |
| 07:00 | 02:30 | |
| 08:00 | 03:30 | |
| 09:00 | 04:30 | |
| 10:00 | 05:30 | |
| 11:00 | 06:30 | |
| 12:00 | 07:30 | |
| 13:00 | 08:30 | |
| 14:00 | 09:30 | Overlap |
| 15:00 | 10:30 | Overlap |
| 16:00 | 11:30 | Overlap |
| 17:00 | 12:30 | |
| 18:00 | 13:30 | |
| 19:00 | 14:30 | |
| 20:00 | 15:30 | |
| 21:00 | 16:30 | |
| 22:00 | 17:30 | Night |
| 23:00 | 18:30 | Night |
London is currently observing daylight saving time, while Kolkata is on standard time. When London switches back to standard time, the difference between these two cities will shift by 1 hour.
The time difference is 4 hours and 30 minutes. London is 4 hours and 30 minutes behind Kolkata.
Yes. One of these cities observes DST while the other does not, so the difference shifts by 1 hour when DST begins or ends.
The best window is between 13:30 and 17:00 Kolkata time, which corresponds to 09:00–12:30 in London. Both sides fall within normal business hours.
Subtract 4 hours and 30 minutes from Kolkata time to get London time. Use the hour-by-hour table above for a quick reference.
For sunrise and sunset data, visit TheSunsetTimes.com. For detailed DST schedules, see DaylightSavingTime.info.