About this tool
Time zones and UTC offset
The big clock uses the time zone your browser reports, for example Asia/Seoul. The UTC offset shows how far that zone is from Coordinated Universal Time: Seoul is UTC+09:00, so when it is 15:00 in Seoul it is 06:00 UTC.
Zone names follow the IANA time zone database, the same list your phone and computer use.
Daylight saving time
Many places move their clocks one hour forward in summer. New York is UTC−05:00 in winter and UTC−04:00 in summer. The world clock calculates each city’s offset for the current date, so it switches automatically on the right day.
Why your device clock may be off
This page reads the clock of the device you are using; it does not ask a time server. Most phones and computers keep themselves in sync automatically, but if automatic time is turned off the clock can drift by seconds or minutes.
If the time looks wrong, turn on automatic date and time in your system settings and reload the page.
Adding cities to the world clock
- Start typing a zone such as Europe/Berlin or America/Chicago and pick it from the list, then press Add.
- Up to 12 cities are shown, each with its time, offset and a Yesterday/Tomorrow label when the date differs from yours.
- Your list is saved only in this browser. Remove a city with its Remove button.