How to convert time zones
- Your own time zone is filled in. Add cities with Add a city or time zone.
- Pick a date and time, or drag the slider. Every row updates together.
- Look for an hour that’s green in every row: that’s working time for everyone.
How it works
Offsets come from the time zone database built into your browser (the IANA database, also used by phones and operating systems), so the tool knows when each place switches to and from summer time, even for past and future dates. Nothing is hard-coded, so when a country changes its rules, an updated browser picks it up.
Your list of cities is saved in this browser so it’s there next time.
Worked examples
- 9:00 on 15 July 2026 in Seoul is 20:00 the previous day in New York (13 hours behind), 01:00 in London and 02:00 in Berlin.
- The same 9:00 in Seoul on 16 November 2026 is 19:00 in New York (14 hours behind), because New York left summer time on 1 November.
- In 2026 the US switches on 8 March and 1 November, the EU on 29 March and 25 October. Between those dates, the New York–London gap is 4 hours instead of 5 for a few weeks.
When to use it
Scheduling a call between Seoul, Berlin and New York. Checking when a product launch, live stream or sports match starts where you are. Planning a flight arrival in local time. Telling a remote team when a deadline really ends.
For a countdown to the event itself, use Date, Age & D-day Calculator. For a timer during the meeting, use Timer, Stopwatch & Pomodoro.
Limits
- City names come from the time zone database, so search for the main city of a zone (for example, “Los Angeles” for California).
- Countries can change their time rules at short notice; very recent changes need an up-to-date browser.
- Working hours are fixed at 9:00–18:00 as a guide; real office hours vary.
Frequently asked questions
Does it handle daylight saving time?
Yes. Each row shows whether summer time is in effect on the selected date, and the offsets change automatically on the switch dates.
How do I find a good meeting time?
Add every participant’s city and drag the slider. When the green bars line up in every row, that hour is within 9:00–18:00 everywhere.
What’s the difference between UTC and GMT?
For everyday use they show the same time. UTC is the precise scientific standard; GMT is also the name of the UK’s winter time zone.
Will my cities be remembered?
Yes, in this browser’s local storage. Clearing site data resets the list.