How do I convert a time between two time zones?

Choose the city you are starting from, pick the date and time in that city, then choose the destination city. The converter works out the real UTC instant for your chosen local time and re-reads it in the destination zone, so daylight saving is handled automatically on both sides.

Does this converter handle daylight saving?

Yes. It uses the IANA time zone database built into your browser, which carries the full historical and future rule set for every zone. Converting a date in January and a date in July between the same two cities can give different offsets, and that is correct.

Why are some time zones not a whole number of hours?

Several zones are offset by thirty or forty-five minutes. India is UTC+5:30, Nepal is UTC+5:45, parts of Australia are UTC+9:30 and the Chatham Islands are UTC+12:45. The converter handles these correctly, which mental arithmetic usually does not.

Time zone converter

Pick two cities and a moment in time. Daylight saving, half-hour offsets and date rollovers are all handled for you.

From

Date in Cardiff

Time in Cardiff

Popular conversions

How time zone conversion works

Every clock on earth is describing the same instant, they simply label it differently. A time zone is an offset from Coordinated Universal Time, and converting between two cities means finding the UTC instant your local time refers to, then reading that instant off the other city’s clock.

The complication is that offsets are not constant. Most of Europe and North America shift by an hour twice a year, and they do not do it on the same dates. For roughly one week each autumn and three weeks each spring, the gap between the UK and the United States is an hour different from what people expect. That single fact accounts for a large share of missed international meetings.

This converter avoids the problem entirely by never assuming a fixed offset. It asks the browser’s own copy of the IANA time zone database what the offset was, is, or will be on the exact date you selected.

Converting time zones, questions

How do I convert a time between two time zones?: Choose the city you are starting from, pick the date and time in that city, then choose the destination city. The converter works out the real UTC instant for your chosen local time and re-reads it in the destination zone, so daylight saving is handled automatically on both sides.
Does this converter handle daylight saving?: Yes. It uses the IANA time zone database built into your browser, which carries the full historical and future rule set for every zone. Converting a date in January and a date in July between the same two cities can give different offsets, and that is correct.
Why are some time zones not a whole number of hours?: Several zones are offset by thirty or forty-five minutes. India is UTC+5:30, Nepal is UTC+5:45, parts of Australia are UTC+9:30 and the Chatham Islands are UTC+12:45. The converter handles these correctly, which mental arithmetic usually does not.