Timezone converter
Compare one UTC instant across IANA timezones with side-by-side clocks and date changes.
How it works & useful details
How it works & limits
Start with an explicit UTC instant and compare up to four distinct IANA timezones. Daylight saving is applied for that instant using your browser’s timezone database. A local time during a DST overlap may occur twice, so this tool deliberately starts from UTC.
UTC years 1900–2100 are supported. Historical and future timezone rules depend on the database shipped with your browser and can change. Clock faces show hours/minutes; digital clocks show seconds. The saved UTC instant preserves milliseconds. No timezone is detected or fetched remotely.
Your working space
Explore the live preview, then save a copyable text report. Inputs stay on this device and are cleared by refreshing. Dates use the Gregorian calendar, including before its historical introduction.
About this tool
Timezone converter takes one UTC instant and shows it across the IANA timezones you select, with side-by-side clocks and a clear note when the date changes. It is useful for scheduling calls across regions and confirming what "next Monday" means in each zone.
Time zones are resolved by your browser’s IANA database, so daylight saving transitions are reflected accurately for the chosen instant. No time-zone service is contacted.
How to use it
- Enter the instant in UTC or pick it from the current time.
- Select the time zones you want to compare.
- Review the local times and note any date shifts.
- Copy the comparison for an invitation or message.
Worked example
12:00 UTC on 2026-03-29 is 14:00 in Amsterdam (UTC+02:00), 08:00 in New York (UTC−04:00), and 17:30 in Kolkata (UTC+05:30). Europe switched to summer time that same morning. A day earlier, Amsterdam was still at UTC+01:00, so the gap to New York was briefly five hours instead of six.
Differences between cities are not constant. Europe and North America change their clocks on different dates, and many countries do not use daylight saving at all. Always convert a specific instant rather than relying on a fixed offset.
Why the tool starts from UTC
A local time can be ambiguous. When clocks go back, 02:30 happens twice. When they go forward, 02:30 does not exist at all. A UTC instant is never ambiguous, so the tool takes one exact moment and shows what the clocks read in each zone.
Zones use IANA names such as Europe/Amsterdam instead of abbreviations like CET or EST, because abbreviations are ambiguous (IST is used in India, Ireland, and Israel) and do not capture daylight saving rules. The rules come from your browser's time zone database, which updates with your browser.
Frequently asked questions
Does it handle daylight saving transitions?
Yes. Each zone is evaluated for the specific instant, so offsets reflect the rules in effect at that moment.
Can I convert from a local time instead of UTC?
The tool works from a single reference instant in UTC to keep the comparison unambiguous; convert your local time to UTC first if needed.
Are historical or future dates supported?
Within the limits of the browser’s time-zone data, yes. Unusually old or far-future zones may differ from printed records.
How do I schedule a meeting across time zones?
Pick a candidate time, convert it to UTC, and enter that instant here with up to four zones. Check that the date is the same for every participant. A late-afternoon slot in California is already the next day in Asia.