Exact time now — check your clock
Your device shows its own clock — the very clock you came to verify. This page compares it against an NTP-synchronized server and states the difference with an honest error margin.
Below, the same page answers the world-clock question: current time in major cities, side by side, computed live in your browser.
UTC now
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Coordinated Universal Time — the reference for every time zone
Your local time, corrected
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Checking against the server…
Check your clock
Measuring: a few requests to the server…
How the result is computed
The page asks the server for its time several times and keeps the sample with the lowest network delay. The offset is the server time plus half the round trip minus your clock's reading. That half round trip is also the error margin: a single HTTP request cannot do better, so with an 80 ms round trip we do not promise hundredths of a second. The server is NTP-synchronized; this is an everyday-accuracy check, not an atomic clock.
How to synchronize your clock
- Windows: Settings → Time & language → Date & time → “Sync now” (or turn on “Set time automatically”).
- macOS: System Settings → General → Date & Time → turn on “Set time and date automatically”.
- Android: Settings → System → Date & time → turn on automatic time (network-provided time).
World Clock
Time zone converter and meeting planner
Compare cities on one shared timeline, move a single cursor through the day, and keep the same view in your browser, account, and URL.
Reference time
00:58
Prague, Czechia / Oct 7
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Prague
Home00:58
Wed, Oct 7
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New York
18:58
Tue, Oct 6
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Shared timeline
Drag the bar to move all cities together
00:58
Prague
HomeUTC+2Czechia / GMT+2
00:58
Wed, Oct 7
Now: 00:58
Previous day
New York
UTC-4United States / EDT
18:58
Tue, Oct 6
Now: 18:58
Previous day
Time zones around the world
Every civil time is an offset from Coordinated Universal Time. Places that observe daylight saving time change their offset twice a year, which is why the table gives January and July separately — in the southern hemisphere the summer offset falls in January.
| City | January 2026 | July 2026 |
|---|---|---|
| Honolulu | UTC−10 | UTC−10 |
| Los Angeles | UTC−8 | UTC−7 |
| Denver | UTC−7 | UTC−6 |
| Chicago | UTC−6 | UTC−5 |
| New York | UTC−5 | UTC−4 |
| São Paulo | UTC−3 | UTC−3 |
| London | UTC+0 | UTC+1 |
| Berlin | UTC+1 | UTC+2 |
| Moscow | UTC+3 | UTC+3 |
| Dubai | UTC+4 | UTC+4 |
| Delhi | UTC+5:30 | UTC+5:30 |
| Beijing | UTC+8 | UTC+8 |
| Tokyo | UTC+9 | UTC+9 |
| Sydney | UTC+11 | UTC+10 |
| Auckland | UTC+13 | UTC+12 |
Where exact time comes from
The reference is Coordinated Universal Time, UTC. It is assembled from hundreds of atomic clocks in laboratories around the world, and national institutes each keep their own realisation of it — in the United States, NIST in Boulder, Colorado, maintains UTC(NIST).
Computers and phones receive the time over the Network Time Protocol: the device asks a server that is itself synchronised to better sources, and allows for the delay of the network. Over the internet that is good to tens of milliseconds. Phones can also take the time from the mobile network.
Why clocks run fast or slow
Computer and phone clocks count time with a quartz oscillator. A typical crystal is accurate to about twenty parts per million — up to 1.7 seconds a day, or up to a minute a month when the clock never checks the network. Temperature and ageing change the frequency, so the drift is not even steady.
When automatic synchronisation is switched off or the device has been offline for a long time, the error builds up unnoticed. The check above shows how far your clock is from the server right now, together with an honest measurement error.