About this online clock
The large time at the top is your local time, read from your device's clock and laid out for your time zone using the official IANA time zone rules built into your browser. It is as accurate as your device: if your computer or phone sets its clock automatically, this clock follows it. It doesn't contact a time server, so we don't claim atomic or verified accuracy.
What each mode does
- Clock: digital or analog, 12- or 24-hour, with or without seconds and the date, in four display styles (Minimal, Desk, Presentation, Classroom), full screen, high contrast and an optional eye-break reminder.
- World Time: as many cities or time zones as you like, side by side, for now or any date and time you choose; a time-zone converter; and a meeting planner that finds times inside everyone's working hours.
- Timer: several countdown timers at once, each with its own name, sound and repeat.
- Stopwatch: laps and splits to the hundredth of a second, with a CSV download.
- Alarm: one-time or weekly alarms in any time zone, while this page stays open.
- Focus: work and break sessions (often called the Pomodoro technique) with optional background noise.
- Countdown: days, hours, minutes and seconds to an event, with a share link.
Clock changes, done properly
When clocks spring forward, some times don't exist (in New York, 2:30 a.m. on 8 March 2026). When they fall back, an hour happens twice (1:30 a.m. on 1 November 2026 comes round twice, an hour apart). This clock never guesses: it tells you and lets you choose. A daily alarm follows the calendar date, so it still rings at 7:00 on the day the clocks change, even though that day is 23 or 25 hours long.
Worked example: Toronto to London
A call at 9:00 in Toronto on 15 January 2026 is at 14:00 in London: Toronto is 5 hours behind Coordinated Universal Time (UTC) in winter and London is on UTC. On 15 July it is still 14:00, because both cities move their clocks forward by an hour in summer (Toronto to 4 hours behind UTC, London to 1 hour ahead). Between mid-March and late March, and again for about a week around the end of October, the gap is only 4 hours, because North America and Europe change their clocks on different dates.
Questions
Is this clock accurate?
It shows your device's time, so it is exactly as accurate as your device. Most phones and computers set their clocks automatically from the internet and are usually within a fraction of a second. If your device clock is wrong, this clock is wrong by the same amount.
Will my alarm ring if I close the tab or my laptop sleeps?
No. A web page can only ring while it is open and the browser is running. Phones and laptops also pause background tabs to save battery, which can delay a ring. When you come back, the page tells you about anything it missed. For important alarms, use your device's built-in alarm.
Do my timers keep running if I switch modes or reload?
Yes. Timers count down to a fixed finishing time, so switching modes, hiding the tab or reloading the page doesn't change when they finish. If a timer finished while the page was closed, you'll see when it actually finished.
Why does the stopwatch say "approximate" after a reload?
While the page is open, the stopwatch uses a precise clock that never jumps. That clock restarts when the page reloads, so the stopwatch carries on from your device's ordinary clock instead, which can be off if the device slept or its clock was changed in the meantime.
What's the difference between a time zone and a UTC offset?
An offset such as UTC−5 is a fixed number of hours. A time zone such as America/Toronto is a set of rules, including when clocks change. That's why this clock always asks for a zone and works the offset out for the exact date.
Where are my settings saved?
Only in this browser, on this device. Nothing is sent to us. The Clear saved data button lists what it will erase before erasing it.
Last reviewed 6 November 2026 by TalosWorks Inc.