Digital Clock
A big, easy-to-read digital clock showing your device's local time with the date and time zone. Toggle 12/24-hour display and seconds, or go full screen for a desk clock.
Reviewed by the CalcCafe editorial team · Last updated 18 July 2026 · How we test our tools
Example
Turn a spare monitor or an old tablet into a desk clock: open this page, tick 24-hour if you prefer 14:05 over 2:05 PM, and press F11 (or use your browser's full-screen mode) so only the clock fills the screen. The seconds toggle is handy either way — on when you are coordinating something to the second, like joining a call or timing an announcement, and off for a calmer display. The stats row confirms the time zone your device is using (for example Asia/Kolkata, UTC+05:30), which is a quick sanity check when your laptop has travelled with you across zones.
How it works
The clock reads your device's system time several times a second and formats it into hours, minutes and seconds, honouring your 12/24-hour and seconds preferences. The date line and time zone come from the same system settings, with the zone name reported by your browser's internationalisation API. Nothing is fetched from a time server by this page — it simply displays what your operating system believes the time is, which is normally kept accurate automatically (see below).
Good to know
How accurate is this? As accurate as your device's clock. Modern operating systems sync themselves against internet time servers using NTP (Network Time Protocol), which typically keeps a connected computer or phone within a few tens of milliseconds of official time as maintained by national laboratories such as NIST. If a device has been offline for weeks its clock can drift by seconds, and the fix is simply to let it sync again in the system date-and-time settings.
12-hour versus 24-hour is largely geography and context. The 12-hour AM/PM convention dominates everyday life in the United States, and is common in India, the Philippines, Australia and Canada, while most of Europe, Latin America and East Asia write times as 00:00–23:59. Even in 12-hour countries, aviation, medicine, the military and railway timetables use the 24-hour clock because it removes AM/PM ambiguity - there is no confusing 12:00 AM with 12:00 PM when midnight is simply 00:00.
This page shows your device's local time: UTC (Coordinated Universal Time, the global reference) plus your time zone's offset, including any daylight-saving shift the zone applies. The stats row shows both the IANA zone name your device reports and its current UTC offset, so you can tell at a glance whether a travelling laptop is still on home time. If you need several cities at once, a world clock is the better tool.
Two practical tips for using this as an always-on desk clock. Full screen (F11 on most desktop browsers) removes the browser chrome and makes the digits readable across a room. And if you leave it running for hours on an OLED screen - many phones, tablets and some monitors - remember that static bright pixels can cause temporary image retention or, over long periods, permanent burn-in; lower the brightness, or let the screen sleep when you do not need it.
Frequently asked questions
Where does this clock get its time from?
From your device's system clock - the same time shown in your taskbar or status bar. Your operating system normally keeps that clock synced to internet time servers via NTP, so it is usually within a fraction of a second of official time.
Can I switch between 12-hour and 24-hour format?
Yes - tick the 24-hour checkbox to switch from 2:05 PM style to 14:05 style, and untick it to go back. You can also hide the seconds for a calmer display. The settings apply instantly.
Is my data uploaded anywhere?
No - this clock runs entirely in your browser and keeps working offline once the page has loaded. It only reads your device's clock and time-zone setting; nothing is sent to a server.
Why does the clock show a different time than my phone?
The clock mirrors the device it is running on. If two devices disagree, one of them has drifted or is set to a different time zone - check that both have automatic date-and-time and automatic time-zone enabled in their system settings.
People also ask
What is the difference between UTC and local time?
UTC is the global reference time kept by atomic clocks; your local time is UTC plus your time zone's offset, including any daylight-saving adjustment. This page shows local time and displays the zone and offset your device is using.
How do I make the clock full screen?
Press F11 on most desktop browsers (or choose Full Screen from the browser menu; on a Mac, use the green window button). Press F11 or Esc to exit. Full screen turns the page into a clean desk or wall clock.
Will an always-on clock damage my screen?
On LCD screens, no. On OLED displays, static bright digits shown for many hours can cause image retention and eventually burn-in, so lower the brightness or allow the screen to sleep if you run the clock continuously.
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Sources & references
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