Kolkata zone
GMT+5:30 (GMT+5:30)
Istanbul zone
GMT+3 (GMT+3)
Difference
2h 30m behind Kolkata
Business overlap
5h (9-5 windows)
Working hours overlap
Each cell is one hour in Kolkata. Filled cells mark when 9 AM – 5 PM in Kolkata and Istanbul both apply.
5 hours per day
- Kolkata
- GMT+5:30
- Istanbul
- GMT+3
- Difference
- -2h 30m
- Business overlap
- 5h
Hour-by-hour conversion
Each row shows the matching local time in Istanbul for an hour in Kolkata.
| Kolkata | Istanbul | Day | Window |
|---|---|---|---|
| 12:00 AM | 9:30 PM | previous day | — |
| 1:00 AM | 10:30 PM | previous day | — |
| 2:00 AM | 11:30 PM | previous day | — |
| 3:00 AM | 12:30 AM | same day | — |
| 4:00 AM | 1:30 AM | same day | — |
| 5:00 AM | 2:30 AM | same day | — |
| 6:00 AM | 3:30 AM | same day | — |
| 7:00 AM | 4:30 AM | same day | — |
| 8:00 AM | 5:30 AM | same day | — |
| 9:00 AM | 6:30 AM | same day | — |
| 10:00 AM | 7:30 AM | same day | — |
| 11:00 AM | 8:30 AM | same day | — |
| 12:00 PM | 9:30 AM | same day | Both 9-5 |
| 1:00 PM | 10:30 AM | same day | Both 9-5 |
| 2:00 PM | 11:30 AM | same day | Both 9-5 |
| 3:00 PM | 12:30 PM | same day | Both 9-5 |
| 4:00 PM | 1:30 PM | same day | Both 9-5 |
| 5:00 PM | 2:30 PM | same day | — |
| 6:00 PM | 3:30 PM | same day | — |
| 7:00 PM | 4:30 PM | same day | — |
| 8:00 PM | 5:30 PM | same day | — |
| 9:00 PM | 6:30 PM | same day | — |
| 10:00 PM | 7:30 PM | same day | — |
| 11:00 PM | 8:30 PM | same day | — |
Best meeting windows
If both teams keep standard 9 AM – 5 PM hours, the overlap window is roughly 12:00 PM – 5:00 PM in Kolkata time. That gives you 5 hours per workday for live meetings.
Tighter overlap is achievable by having the side with later working hours start earlier, or by treating the first and last hours of each side as flexible. The bar above marks every hour where both cities sit inside a 9 AM – 5 PM window.
About converting Kolkata time to Istanbul time
Kolkata follows the Asia/Kolkata time zone (currently GMT+5:30, GMT+5:30), while Istanbul follows Europe/Istanbul (currently GMT+3, GMT+3). Istanbul is 2h 30m behind Kolkata right now.
Neither city observes daylight saving time, so the offset between them is the same all year.
Reverse this conversion
Istanbul to Kolkata
Open the converter
Plan a meeting between Kolkata and Istanbul
More conversions from Kolkata
Frequently asked questions
- How many hours is Kolkata from Istanbul?
- Istanbul is 2h 30m behind Kolkata right now.
- What time is 9:00 AM Kolkata in Istanbul?
- 9:00 AM in Kolkata is 6:30 AM in Istanbul.
- What time is 5:00 PM Kolkata in Istanbul?
- 5:00 PM in Kolkata is 2:30 PM in Istanbul.
- When do Kolkata and Istanbul business hours overlap?
- Standard 9 AM - 5 PM working hours overlap for about 5 hours, roughly from 12:00 PM to 5:00 PM in Kolkata time.
- Does daylight saving time change the difference between Kolkata and Istanbul?
- Neither Kolkata nor Istanbul observes daylight saving time, so the offset between them is constant year-round.
Local time page
Time in Kolkata
Local time page
Time in Istanbul