Time Zone Converter
Convert a date and time from one time zone to another, using the zone database already built into your browser. Daylight saving is handled for you: the tool works out the offset that actually applied on the date you picked, not a fixed number, so a summer meeting and a winter one convert differently. You get the converted time, both UTC offsets and the difference between them.
Offsets come from your own device. The conversion uses the IANA time zone rules built into your browser, including the daylight saving rules in force on the date you picked — nothing is hardcoded here. Those rules update with your browser or operating system, so a device that has not been updated in a long time may be out of date for a country that recently changed its clocks. Everything runs locally; nothing you enter is sent anywhere.
How to convert a time between zones
- Pick the date and time you want to convert, or press Now for the current moment.
- Choose the zone that time is in, then the zone you want it in — “Use my time zone” fills in your own.
- Read the converted time, both UTC offsets and the difference between them.
When you'd use this
- Scheduling a call across countries — Check what 09:00 in one city lands on in another before you send the invite.
- Reading a deadline in another zone — Turn a submission cut-off quoted in one zone into your own local clock time.
- Planning around a daylight saving switch — Compare the same meeting on a date before and after a clock change to see whether it moves.
- Checking a timestamp from a log or email — Convert a time recorded in UTC into the local time of the place it matters.
Good to know
- Daylight saving is worked out per date — The offset is read from your browser's time zone rules for the exact date you entered, so New York converts differently in January and July. Nothing about the offsets is fixed in the code.
- The zone rules come from your device — They are part of your browser or operating system and are refreshed when those update. A device that has not been updated for a long time can be wrong for a country that recently changed its clock rules.
- Some local times do not exist — On the night clocks jump forward an hour is skipped. If you enter a time inside that gap the tool says so and converts the moment that time becomes after the jump, which is what a real clock does.
- Some local times happen twice — When clocks go back, an hour repeats. The tool uses the first, earlier occurrence and tells you it did, so you can add an hour if you meant the second one.
Frequently asked questions
Does this handle daylight saving time?
Yes. It asks your browser for the offset that applied in that zone at that exact date and time, so the same clock time converts differently in summer and winter. No offsets are hardcoded.
Why does the UTC offset change depending on the date?
Because many zones move their clocks twice a year. New York is UTC-05:00 in January and UTC-04:00 in July, so the same wall-clock time gives two different answers. The offsets shown are the ones in force on the date you chose.
What happens if the time I enter does not exist?
On the night clocks jump forward, an hour is skipped entirely. The tool tells you the time was skipped and converts the moment that clock reading becomes after the jump, then shows the local time it actually corresponds to.
Can I use a zone that is not in the list?
Only your own. "Use my time zone" reads the zone your device is set to and adds it to both lists if it is not already there. Other zones cannot be typed in, so the list is about three dozen widely used ones.
Is anything I enter sent to a server?
No. The conversion runs entirely in your browser using the time zone data it already ships with. There is no upload, no account and no logging of what you type.