World Clock

Your own local time sits at the top, followed by Karachi, Dubai, Mumbai, London, Berlin, New York, Chicago, Los Angeles, Toronto, Sao Paulo, Singapore, Tokyo and Sydney. Every row shows the time with seconds, the day and date, the UTC offset and how far ahead or behind you that city is, updating each second.

How to use this world clock

1. Start with the first row. It is your own device time, and every gap on the page is measured against it.
2. Scan the default list of 14 rows for the city you need. The time, day and date, UTC offset and gap from you sit on the same line.
3. Add more cities from the add list when yours is missing. Twelve more are on it, taking the page to 26 rows.
4. Read the gap before you book anything. “Five hours behind you” is the difference between a fair meeting slot and a 3 a.m. call.
5. Download a text snapshot when you need the times frozen, for a plan, a message or an itinerary.

The clock ticks once a second and needs no refresh. Leave it open on a second screen and it behaves like the wall of clocks in a newsroom, minus the wall.

Half hours, the date line and daylight saving on a world clock

Not every offset is a round hour. Mumbai sits at UTC+5:30 all year, half an hour off the neat grid, because India keeps one zone for the whole country and set it between the hours. Karachi, at UTC+5, is exactly half an hour behind Mumbai, a gap that catches people who assume neighbours share round numbers.

Daylight saving bends the gaps twice a year. London and New York are usually five hours apart, but for a few weeks each spring and autumn the gap runs at four or six hours, because the two places change their clocks on different weekends. Every row here recalculates from the current rules, so the gap shown is the gap today, not the gap from a fixed table.

The date line bends the day itself. Sydney can sit a full calendar day ahead of Los Angeles while being only about a day ahead in hours minus a handful, which is why each row carries its own day and date rather than borrowing yours. A call that is Tuesday morning for one side can be Wednesday for the other, and the row says so before you dial.

Details and limits of this world clock

One honest fact sits under the whole page: every time here comes from your own device clock. The browser pairs that clock with its built in timezone database to work out each city’s time, daylight saving rules included. There is no ToolPeko time server checking anything. A device that syncs its clock, as phones and most laptops do, keeps every row honest. A device set wrong by hand shifts all 26 rows by the same wrong amount.

The timezone rules come from the database inside your browser, which is updated as the browser updates. When a government changes a rule, a new start date for daylight saving or a zone dropped entirely, an old browser can show an old answer until it updates. Browsers handle this well in practice, and it is the same source every phone clock uses.

The list covers 26 major cities and the zones they stand for, not every town on earth. Plenty of places share a zone with a listed city, and that row serves them all. If your city keeps the same offset and rules as one on the page, its time is already there under another name.