Time Zone Converter

How to use the Time Zone Converter

1. Pick the date and time, and the zone that time is in.
2. Choose the zone you want it converted to.
3. Press Convert. The table at the bottom shows the same moment in nine major cities.

Why the date matters as much as the time

Time zone offsets are not constant. Most of Europe and North America shift by an hour twice a year, and the changeover dates differ — the US switches in mid-March and early November, the EU on the last Sundays of March and October. For a fortnight each spring, the gap between London and New York is four hours rather than the usual five.

Because of this, converting "3pm next Tuesday" is a different calculation from converting "3pm today". This tool uses your browser's IANA time zone database and applies the rules in force on the specific date you pick, so scheduling across the changeover works correctly.

Zone names, not offsets

Zones are identified as Region/City — Europe/London, Asia/Kolkata — rather than as offsets like UTC+1. This matters because an offset is only true for part of the year, while a zone name carries the full history of that region's rules.

Abbreviations are worse than offsets. "CST" means US Central Standard Time, China Standard Time and Cuba Standard Time, spanning fourteen hours of difference. If you are writing a meeting invitation, name the city.

Not every zone is a whole number of hours from UTC either: India is UTC+5:30, Nepal UTC+5:45, and parts of Australia UTC+9:30. Any system that stores offsets as whole hours will eventually get these wrong.

Frequently asked questions