Time Zone Converter
Convert a date and time from one time zone to another, with the offsets and daylight saving actually in force that day.
Give a date, a time and the zone you meant it in, and get the same instant as it reads on a clock somewhere else. Offsets are taken from the rules in force on that date, not from today.
How it works
The date and time you enter are read as a wall-clock reading in the source zone, which fixes a single instant. That instant is then expressed in the destination zone. Both offsets are looked up for that particular date, because a zone can be five hours from another in January and six in July.
Time zone data comes from the IANA time zone database bundled with the server. When a country moves its clocks or abolishes daylight saving, that database is what changes; nothing about the rules is written into this tool.
On the day the clocks go forward, an hour is skipped and the times inside it never happen. Asked for one, the tool still shows the instant your input resolves to, and says plainly that the time you typed did not exist.
Examples
| Case | Input | Result |
|---|---|---|
| The night the clocks go forward in Europe | 2026-03-29 02:30 UTC to Europe/Paris | 04:30, summer time already in force |
Frequently asked questions
Why is the difference between two zones not always the same?
Because daylight saving starts and ends on different dates in different places, and some zones do not observe it at all. Paris is six hours ahead of New York for most of the year and five for the few weeks in spring and autumn when only one of them has changed its clocks. This is why the difference is computed for the date you gave.
What does it mean that my time did not exist?
On the spring-forward morning the clocks jump, in central Europe from 02:00 straight to 03:00. Nothing between the two ever showed on a clock in that zone. Rather than move your time by an hour without saying so, the tool tells you.
And the hour that happens twice in autumn?
It is ambiguous rather than impossible: 02:30 comes round once before the change and once after. The earlier of the two is used, which is the usual convention.
Why identifiers like Europe/Paris rather than CET?
Abbreviations are ambiguous - CST is claimed by at least three zones - and they do not carry the daylight saving rules. A region identifier does, which is why it is what the database is keyed on.
Good to know
- Offsets and daylight saving rules come from the IANA time zone database on the server, applied for the date you enter.
- Historical dates use the rules recorded for that period, which for the more distant past are themselves approximations made by the database maintainers.