Free Online World Clock

Each city card shows the current local time, the date (which may differ from yours by a day near the international date line), the offset from UTC and whether daylight saving time is currently in effect. Your own city is listed first, so a glance across the cards tells you which colleagues are still asleep, which are at lunch and which have already gone home. Cities update every second from your device's clock, so the page is only as accurate as that clock; on a computer that syncs with an internet time server it is typically within a fraction of a second.

The most common scheduling error is not the arithmetic; it is daylight saving. Europe changes its clocks on the last Sunday of March and October, most of the United States and Canada on the second Sunday of March and the first Sunday of November, and many countries, including Japan, China, India and most of Africa and South-East Asia, do not change at all. For two or three weeks each spring and autumn the gap between London and New York is four hours instead of five, and a recurring 9:00 call silently moves by an hour for one side. The world clock shows the live offset for each city, which sidesteps the whole problem: look at the actual times, not the remembered difference.

For a one-off meeting, find an hour that falls inside 9:00–17:00 for everyone. London, New York and San Francisco overlap only between 16:00 and 17:00 London time; add Sydney and there is no overlap at all, which is why global teams rotate the inconvenient slot. The time zone converter lets you enter a proposed time and see it in several zones at once, and our time zones guide explains UTC, offsets and the odd half-hour zones.

Use Add City to search by city name. Each city is tied to its IANA time zone (for example Europe/Istanbul), so daylight saving rules are always the official ones for that place rather than a fixed offset. Your selection is saved in the browser, so the same set of cities reappears next time you open the page on this device. If you only need a single time, the current time page shows your own local time, date and time zone in a larger format.

• There are 38 different UTC offsets in use, from UTC−12 to UTC+14, so at some moments three calendar dates exist simultaneously on Earth.
• India (UTC+5:30), Iran (UTC+3:30), Afghanistan (UTC+4:30) and parts of Australia (UTC+9:30) use half-hour offsets; Nepal is on UTC+5:45.
• China spans five geographical zones but keeps a single national time, UTC+8.
• Türkiye moved permanently to UTC+3 in 2016 and no longer observes daylight saving.
• Aviation, shipping and computer systems use UTC so that timestamps mean the same thing everywhere; the Unix timestamp converter shows how that looks in practice.