Free · full screen · seconds display
Digital clock
Big enough to read from across a classroom or workshop. Toggle seconds, switch 12/24-hour, press F for full screen. The Smart scene changes with the time of day.
How do I get a full screen digital clock?
Press F, or use the full screen control. The digits scale to fill the space, which is the point when the clock is on a second monitor across a room or projected in a hall. The zoom controls beside it adjust digit size independently of full screen, and the setting is remembered, so a display that is right for your room stays right.
Why does my computer clock drift?
Most do not any more, because they check in with a time server periodically and correct themselves. Where drift still shows up is on machines that have been offline for a long stretch, or where the hardware clock battery is failing on an older desktop. This page reads your system time, so if the machine is wrong the page is wrong with it; the fix is at the operating system level rather than here.
What this page does avoid is a different problem: a clock that falls behind because the browser throttled its timer. The display is recalculated from the system clock on every tick rather than incremented, so it cannot accumulate error no matter how long the tab has been open.
Can I switch to 24-hour time or hide the seconds?
Both, along with showing or hiding the date. Preferences are stored in your browser, so the clock looks the way you left it next time. If you specifically want 24-hour with the conventions explained, the military time page covers that in more detail.
Frequently asked questions
- How do I make the clock full screen?
- Click the Fullscreen button or press F. Press Escape (or F again) to exit. In full screen the clock keeps your display awake.
- Is the clock accurate?
- It reads your device's system clock, which modern systems sync over NTP — typically within a fraction of a second of official time. If your device clock is right, this is right.
- Can it show seconds and a date?
- Yes — both toggle in the control bar and your choices persist for the next visit.
- What is the Smart scene?
- The default backdrop resolves to the time of day: dawn photography at dawn, bright sky at midday, stars at night. Pick any fixed scene instead from the theme row.