Time Zone Converter
Convert a time across zones with daylight saving handled, and a warning near the changeover dates.
About this tool
Converts a moment in time into every major zone at once, using the real time zone database rather than fixed offsets.
**That distinction matters more than it sounds.** An offset is only correct on the day you looked it up: "UTC+1" is London in summer and Berlin in winter. A recurring meeting scheduled by offset drifts by an hour twice a year for half the people in it, and the people it drifts for are never the ones who scheduled it.
The tool also flags a conversion falling within a week of a daylight saving change in either zone. That is when the usual gap between two cities is briefly wrong — the northern and southern hemispheres change on different dates, so for a few weeks each year the difference is an hour off what everybody has memorised.
Enter a time and a zone, and get every other zone alongside it.
Common questions
Why use a zone name rather than an offset?
Because an offset describes one moment and a zone describes a rule. Europe/London is UTC+0 in January and UTC+1 in July; storing "+00:00" makes every summer date wrong by an hour.
Why does the gap between two cities change?
They change clocks on different dates, and the southern hemisphere changes in the opposite direction. London and New York are five hours apart most of the year and four for two weeks in spring.
What should I store in a database?
UTC, always, plus the zone name separately if the local wall-clock time matters. Storing local time without a zone is unrecoverable — you cannot tell later which hour it meant on a day the clocks went back.
Which places do not use daylight saving?
Most of Asia and Africa, all of India and China, and increasingly parts of Europe and the Americas. The table shows whether each zone is currently observing it, which is the only reliable way to know.