UtilTools

Time Zone Converter

What time is it there, and when should we meet?

Time Zone Converter converts a time between any IANA time zones using your browser's built-in zone database, so daylight saving transitions are handled correctly rather than by a fixed offset. Compare several cities on one row and find the hours that are reasonable for everyone. Nothing leaves your device.

Loading Time Zone Converter…

Runs entirely on your device. No file or text you enter here is uploaded. How to verify it.

How to use Time Zone Converter

  1. Set a date, a time and a source zone.
  2. Add the cities you want to compare.
  3. Read the converted times, or scan the overlap band for a meeting slot.

Questions about Time Zone Converter

Where does the time zone data come from?
Your browser's own copy of the IANA time zone database, through the Intl API. It is updated with the browser, so DST rule changes arrive without this page needing to know about them.
Why not just use UTC offsets?
Because offsets change. "New York is UTC−5" is true in winter and wrong in summer, and the switch dates differ between countries and have been changed by legislatures at short notice. Converting by zone name is the only reliable way.
Does it handle historical dates?
Within the limits of the browser database, yes — pick a date in the past and the rules that applied then are used, including the years when DST started on different dates.
Do the cities I add stay there next time?
Yes, up to twelve of them. The list is kept in your browser's local storage on this device only, so it survives a reload but does not follow you to another computer and is never sent anywhere. Clearing site data resets it.
What happens on the day the clocks change?
The conversion follows the real rules for that date, so an hour can appear twice or not at all. Booking a call in the missing hour on a spring-forward morning is exactly the mistake a fixed-offset calculator lets you make and this one does not.
Is Time Zone Converter really free, with no limits?
Yes. There is no account, no daily cap, no file-size tier and no watermark, because there is no server cost to recover. The site is funded by clearly disclosed partner recommendations on the Partners page, never by metering the tools.
Are my files or text uploaded when I use Time Zone Converter?
No. Everything is processed by JavaScript running in your browser, on your device. You can verify it: open your browser's developer tools, switch to the Network tab, and use the tool. You will see no request carrying your data — because there is nowhere for it to go.