Enter a date and time in one city and read it in every other city you follow. Free, and it uses the browser's own IANA time-zone data, so it works offline.
You give the tool one moment: a date, a time, and the city whose clock that time is on. Every card then shows the same moment, written in its own city's clock.
Add a city with the search box. It covers the identifier, a city name, its region and the names it is also known by, so Bombay finds Mumbai and Vizag finds Visakhapatnam. Up to 12 cards are kept, for as long as the page is open.
The offset is worked out for the moment you chose, not looked up in a table. The tool writes that moment out in the zone, reads it back, and compares the two. The difference is the offset, taken from the browser's own IANA time-zone data. This matters because an offset is not a property of a city. It is a property of a city on a date.
On 14 January 2026, 09:30 in New York is 14:30 in London, 20:00 in Kolkata, and 01:30 on 15 January in Sydney. The Sydney card reads Next day.
On 14 July 2026 the same 09:30 in New York is 14:30 in London, 19:00 in Kolkata, and 23:30 in Sydney, on the same day. London moved with New York, so that gap held. Kolkata and Sydney did not, so both changed.
The two are usually five hours apart, and for three weeks each March they are four. On 1 March 2026, 12:00 in London is 07:00 in New York. On 10 March it is 08:00. On 1 April it is 07:00 again.
New York moves its clocks forward on the second Sunday in March, and London on the last Sunday. In between, New York has moved and London has not.
Yes. The date and time field opens on the current moment, so the cards read the time in each city as you arrive. Change the field to read any other moment instead.
The one named in the second field. It starts on the zone your device is set to, as the browser reports it. Change it when the time you are converting belongs to somewhere else.
Because that city moves its clocks. London is UTC in January and UTC+01:00 in July. The offset shown is the one that applied on the date you chose, which is why converting a date in July and a date in January can give two different answers for the same clock time.
Because it is summer in the southern half of the world. Sydney reads UTC+11:00 and Daylight saving time in January, and UTC+10:00 and Standard time in July.
Press Copy times. Every card goes to the clipboard as one line, with the name, the date, the time and the offset. Some browsers do not let a page write to the clipboard at all.
Yes. The zone rules are already in the browser, so no request is made. The cities stay while the browser tab is open, and go when it closes. There is no account, and nothing is sent to a server.
An hour is skipped every spring and repeated every autumn. When New York moves its clocks forward at 02:00 on 8 March 2026, the times from 02:00 to 02:59 do not happen there. A tool asked to convert one of them has to choose an answer, because the moment does not exist.
To convert a length of time rather than a point in it, use the Time Unit Converter. Hours into days is a different question from 09:30 in New York into Kolkata.
The IANA time-zone database holds one zone for each region whose clocks have agreed since 1970. A zone is named Area/Location, and the location is usually a large city rather than a country, because a country can split, be renamed or change its offset, while a city stays put.