Time Zone Converter

Planning a meeting step by step

1. In From, choose the zone in which you know the time. The list starts on your own zone as detected by the browser.
2. Enter the date and time in the picker. Now fills in the current moment for the chosen zone.
3. Pick other places in Add city/zone and press Add. Each one becomes a row showing the local weekday, date and time at that moment.
4. Look at the colours. A time shown in green falls between 9:00 and 17:59 on the local clock, so it is easy to see who would be dialling in during office hours.
5. Remove a row with the × button. The source zone is always shown first and cannot be removed.

What the zone names mean

The dropdowns list IANA time zone identifiers such as Asia/Seoul or America/New_York, taken from the list your browser knows about, with UTC added if it is missing. Zones are named after a representative city rather than an abbreviation like EST or CST, because abbreviations are ambiguous: "CST" can mean US Central, China or Cuba. If your city is not listed, choose another city in the same region that shares its rules.

How the conversion is done

A date and time typed without a zone is only a wall-clock reading. To convert it, the page first treats the digits as if they were UTC, asks the browser what offset the chosen zone had at around that moment, and subtracts it. It repeats the step once more with the corrected instant, because the offset on the date you chose can differ from the one on the guessed date when a daylight saving change is close by. The resulting instant is then formatted separately for every zone in the list.

Example in January: 09:00 on a Monday in New York (UTC−5) is 14:00 UTC. London, on UTC+0 in winter, shows 14:00, and Tokyo, at UTC+9, shows 23:00. London is green, Tokyo is not. Nothing in the list is green for everyone, so a call between those three always asks someone to work early or late.

Day changes appear too. 10:00 on Tuesday in Tokyo is 20:00 on Monday in New York in January. That is why the weekday is printed next to each time.

Daylight saving traps

Countries start and end daylight saving on different dates, so the gap between two cities is not fixed through the year. In 2026 the United States changes clocks on 8 March while most of Europe changes on 29 March. For three weeks New York and London are four hours apart instead of the usual five. Always pick the real date of your meeting, not today's date, and let the converter apply the rules for that day.

Zones with half-hour offsets such as Asia/Kolkata (UTC+5:30) show minutes in the result, and some zones do not observe daylight saving at all. When you type a time that does not exist because clocks skipped forward, or that happens twice when clocks go back, the page settles on one valid moment rather than showing an error. For those hours of the year, double-check the result with the participants.

Common uses

• Remote team meetings: add every teammate's city and look for the hour that is green in most rows.
• Webinars and live streams: convert the start time into the zones of your main audiences before publishing the schedule.
• Travel: check the local time at your destination on the day you land, including whether it is already tomorrow there.
• Calling family abroad: find a time that is neither dawn nor midnight for either side.

Tips and limits

• The green highlight only looks at the hour. It uses a fixed 9:00 to 18:00 window and does not know about lunch breaks, weekends or public holidays, so check the weekday shown next to each time.
• Your added cities are saved in this browser's local storage. If you clear site data or use a private window, the list returns to its default of New York, London and Tokyo.
• The list in your browser follows its bundled time zone database. Very old browsers may show a shorter list, and recent rule changes in a country may take a browser update to appear.
• The page converts one moment at a time. For a recurring meeting that crosses a daylight saving date, check each side of the change separately.

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