Display options
Switch between 12 and 24-hour format, show or hide seconds, and add milliseconds when you need to see the clock actually moving. Pick any timezone and the date updates with it. Your choices are remembered in your browser for next time.
Full screen
The full-screen button strips everything except the time, which is what you want for a projector, a spare monitor, a shop display or a lecture theatre. Press Escape to come back.
How accurate is it?
The clock reads your device system time, which on any modern machine is kept within a fraction of a second of true time by network synchronisation against a pool of reference clocks. If this page disagrees noticeably with another clock you trust, the device is the thing to check: on most systems automatic time synchronisation can be switched on in the date and time settings, and it will correct itself within a few seconds.