Timezone converter

What is a Timezone Converter?

Scheduling a call, reading a server log or planning a release across countries all require converting times between time zones. Daylight saving time makes it harder: offsets change on different dates in different regions. This converter uses the IANA time zone database, the same one used by operating systems and programming languages, so DST rules are applied correctly for the specific date.

How to use it

  1. Enter the date and time.
  2. Choose the source time zone.
  3. Choose the target time zone and read the converted date and time.

Example

A meeting at 09:00 on 10 November 2026 in New York (America/New_York, EST, UTC-5) is at 19:30 in Kolkata (Asia/Kolkata, IST, UTC+5:30) and 14:00 in London (Europe/London, GMT, UTC+0). In July, the same 09:00 New York meeting is at 18:30 in Kolkata, because New York is on daylight time (UTC-4) while India does not use DST.

Why use IANA names

Abbreviations like IST or CST are ambiguous: IST means India, Irish or Israel Standard Time, and CST can be US Central or China Standard Time. IANA names such as Europe/Dublin or Asia/Shanghai are unambiguous and carry the full history of offset changes.

Tips

  • Store timestamps in UTC and convert only for display.
  • Watch the DST transition weeks in March, April, October and November, when the gap between regions temporarily changes because the US and Europe switch on different dates.
  • Times that do not exist (skipped when clocks spring forward) or occur twice (when clocks fall back) need special handling in software.

Frequently Asked Questions

Does the converter handle daylight saving time?

Yes. It uses the IANA time zone database, which applies the correct DST rules for the selected date.

Why should I use IANA names instead of abbreviations?

Abbreviations like IST and CST are ambiguous. IANA names like Asia/Kolkata identify a region exactly.

What is the time difference between India and the US East Coast?

India is 10 hours 30 minutes ahead of New York when New York is on standard time (winter), and 9 hours 30 minutes ahead during US daylight saving time (summer).

Should I store times in local time or UTC?

Store them in UTC and convert to the user's time zone only when displaying them.

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