Time Zone Converter
Convert a local date and time between countries, cities and regions, with daylight saving changes and UTC offsets included.
IANA tzdb 2026f. Calculations stay in this browser. Future rules may change after this saved release.
Compare appointment times across countries without treating every country as a single time zone. Choose a representative city or region for each location; the displayed IANA identifier identifies the rule set used. Countries with several regions require an explicit regional choice when you change the country.
How to use this tool
- Choose the source country and city or region, then choose the destination.
- Enter the date and wall-clock time at the source. The date matters because UTC offsets can change during the year.
- If the time repeats when clocks move back, select the earlier or later occurrence by its offset and UTC instant.
- Read the full destination date, time and UTC offset. Swap locations to reverse an already resolved conversion while preserving the instant.
Formula
UTC instant = source local time − source UTC offset; destination local time = UTC instant + destination UTC offset.
Offsets are looked up for the actual instant in saved IANA tzdb 2026f rules. A forward clock jump can leave a range of local times with no matching instant; the converter rejects those times instead of silently moving them. A backward jump can produce two matching instants.
Example
On 15 July 2026, 09:00 in New York is 13:00 UTC and 22:00 in Seoul. On 1 November 2026, 01:30 in New York occurs twice: 05:30 UTC at UTC−04:00, or 06:30 UTC at UTC−05:00.
Frequently asked questions
Why must I choose a city or region?
The United States, Australia and many other countries have multiple rule sets. The menu lists representative IANA locations, not every city. Select the region that actually governs your location; a familiar nearby city is not always sufficient.
Does this depend on my device’s time-zone rules?
Conversion uses the saved 2026f rules, so an older browser database cannot change the answer. Your device zone is used only to suggest the initial source location, and its clock supplies the current-time button.
How reliable are future and historical dates?
The tool covers 1970–2100. Future results project the rules in this release and can change after governments revise them. Historical coverage follows IANA records. Seconds are ordinary civil seconds; leap-second inputs are not supported.
Sources
Last updated: 2026-10-30