Time Zone Converter

A worked conversion

Take Monday 19 October 2026 at 09:00 in New York. New York is still on daylight time until 1 November, so that is UTC minus 4, which makes it 13:00 UTC. Each row then applies its own offset for that date: London is on summer time until 25 October (UTC plus 1), Dubai is fixed at plus 4, India at plus 5:30, Tokyo at plus 9 and Sydney at plus 11 during its daylight-saving period. The rows the tool shows:

How the conversion works

No time zone library is downloaded. The tool uses the Intl date formatting built into every modern browser, which carries the IANA zone database and its daylight-saving rules. The wall-clock time you enter is first turned into a UTC instant by looking up the source zone's offset, and that single instant is then formatted in each target zone. Times are shown with a 12-hour clock and AM or PM, dates as weekday, month and day without the year, and seconds are not supported.

The result rows do not print the offset, so if you need the UTC difference itself, add UTC as a city and compare it with the source.

Cities you can pick and their offsets

If your device is set to a zone outside this list, it still appears at the top of the source menu as your time, but it cannot be added as a target row. Paris / Berlin covers the whole Central European zone, so it serves for Madrid, Rome, Amsterdam and Warsaw as well.

Daylight-saving edge cases

• The wall time is converted in two passes: the zone's offset is read on either side of the moment you typed, each offset gives a candidate instant, and each candidate is formatted back in the zone to see which one really shows your time. Entering 03:30 in New York on 8 March 2026, the first hour after the clocks jumped, gives 07:30 UTC, the same instant the city's clocks actually showed as 03:30.
• A time that never existed, such as 02:30 on that same morning, is moved forward to 03:30.
• A time that happens twice when clocks go back is taken as its first, daylight-time occurrence.
• Between mid-March and late March, and again from late October to early November, Europe and North America are not in step, so the usual five-hour gap between London and New York becomes four. The tool handles this; just be aware the difference you remember may be wrong for those weeks.

Planning a call across several zones

• Set the source to the organiser's zone and enter the proposed slot once; every row updates together.
• Watch the date column. A 4 PM slot in Los Angeles is already the next morning in Sydney and Auckland.
• For a recurring meeting, check a date in each half of the year, since zones with and without daylight time drift by an hour against each other.