Best overlap: 8:00 AM to 2:00 PM in Kolkata is 12:00 PM to 6:00 PM in Adelaide.
8:00 AM to 2:00 PM in Kolkata is when Adelaide is also working, at 12:00 PM to 6:00 PM their time. Adelaide is 4 hours ahead of Kolkata, and with 6 hours of overlap you can even run back-to-back calls without stepping outside business hours. Watch the DST gap — when Adelaide changes its clocks and Kolkata stays the same, this window slides by an hour.
| Local time | 12am | 1am | 2am | 3am | 4am | 5am | 6am | 7am | 8am | 9am | 10am | 11am | 12pm | 1pm | 2pm | 3pm | 4pm | 5pm | 6pm | 7pm | 8pm | 9pm | 10pm | 11pm |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Kolkata Asia/Kolkata | ||||||||||||||||||||||||
Adelaide Australia/Adelaide |
A complete guide to time zones in 2025, from UTC and GMT differences to Daylight Saving Time changes, IANA database rules, abbreviation pitfalls, and developer best practices for handling global time. -