How to convert a time between zones
- Choose From time zone. It starts on your device's zone; pick another if the time you have is from somewhere else.
- Set Date and time, or press Use current time.
- Read each row under Show in. It gives the local date and time, the zone abbreviation and UTC offset, and whether that day is the same, the next or the previous one.
- Press + Add another zone for up to five rows, use the cross to drop one, or tap a preset for a common pair. The 12-hour and 24-hour buttons change how times are written.
How the conversion works
Your browser ships the IANA time zone database and exposes it through Intl.DateTimeFormat. The tool takes the clock time you typed, finds the UTC offset that the From zone uses on that date, and turns the clock time into one exact moment. It then writes that moment as a local time in every row. Because each zone's own rules are applied, an offset can change by an hour twice a year without any special handling.
Worked example
The default rows are London and Tokyo. Set From time zone to New York (US Eastern) and Date and time to October 5, 2026, 9:00 AM. New York is on daylight time (UTC-4), London is on British Summer Time (UTC+1) and Tokyo is on UTC+9, so the tool shows:
London: Mon, Oct 5, 2026, 2:00 PM
Tokyo: Mon, Oct 5, 2026, 10:00 PM
That is 5 hours ahead for London and 13 hours ahead for Tokyo. A few weeks later the answer shifts: at 9:00 AM on October 26, 2026 London is back on UTC+0 while New York is still on UTC-4, so London reads 1:00 PM, only 4 hours ahead.
Limits and edge cases
- Skipped and repeated times. When clocks spring forward, a time such as 2:30 AM on March 8, 2026 does not exist in New York. The tool moves it forward by the skipped hour and says so. When clocks fall back, a time like 1:30 AM on November 1, 2026 happens twice; the tool uses the first one and notes it.
- Date range. Dates from 1900 to 2100 are accepted. For years after about 2037 your browser assumes today's rules, and governments sometimes change them.
- Your clock. Use current time and the world clock rely on your device's clock being correct.
- Zone lists. The Popular group covers major cities; the All time zones group lists every zone your browser knows.
If you only need the current time somewhere, the world clock is quicker. For Unix times use the timestamp converter, and to count days between two dates try the date difference calculator.
Frequently asked questions
What is the time difference between New York and London?
London is usually 5 hours ahead of New York. The gap drops to 4 hours for a few weeks when the US and the UK change their clocks on different dates, which in 2026 is March 8 to March 28 and October 25 to October 31.
Does this converter handle daylight saving time?
Yes. It converts with the IANA time zone rules built into your browser, so each zone uses the offset that applies on the date you enter, including the days around a clock change.
What is the difference between EST and EDT?
EST is Eastern Standard Time (UTC-5, used in winter) and EDT is Eastern Daylight Time (UTC-4, used in summer). Choosing New York as the zone applies the right one for the date automatically.
What does IST mean when I convert a time?
IST can mean India Standard Time (UTC+5:30), Irish Summer Time or Israel Standard Time. To avoid a mix-up the converter uses place names such as India (Kolkata) instead of abbreviations.
Sources: IANA Time Zone Database; NIST, daylight saving time; timeanddate.com, 2026 daylight saving dates.