How to convert time between time zones
- Type the date and time as YYYY-MM-DD HH:mm using a 24-hour clock. Leave it empty to use the current moment.
- Enter the city or zone it is from, such as New York or Asia/Kolkata.
- List the cities to convert to, one per line or separated by commas.
- Read each city’s local time, weekday, date and UTC offset. Cities on a different day are marked next day or previous day.
How it works
There is no network lookup. Your browser already knows the rules of every time zone through the standard Intl API, including the dates when each place changes its clocks. The tool turns the wall-clock time you typed into an exact moment, then asks the browser what the wall clock says elsewhere at that moment.
Daylight saving is why a fixed “New York is 5 hours behind London” fails. The gap is 5 hours most of the year but 4 hours for a few weeks in March, when the US has already moved clocks and the UK has not.
Worked example
A call is set for Monday 9 March 2026 at 12:00 in New York.
- New York is on daylight time (UTC-4), because US clocks moved forward on 8 March.
- London is still on UTC+0, so it is 16:00 the same day.
- Kolkata is UTC+5:30, so it is 21:30.
- Tokyo is UTC+9, so it is 01:00 on Tuesday, shown as next day.
One week earlier, on 2 March, the same noon in New York would be 17:00 in London, one hour later than today. That surprise is the reason to calculate with a date.
Skipped and repeated hours
On 8 March 2026 New York clocks jump from 02:00 to 03:00, so 02:30 never happens. The tool moves it to 03:30 and shows a note. On 1 November 2026 the hour from 01:00 to 02:00 happens twice, and the first one is used.
Related tools
To count days between meetings, use the date difference calculator. To add a number of days to a date, try add days to date. For duration math, see hours to minutes. The conversion runs in your browser and nothing is uploaded.