World clock with seconds
Seconds are the same everywhere — every civil time zone is offset by a whole number of minutes — so a ticking display is about confidence, not accuracy.
The short answer
Every time zone in current civil use is offset from UTC by a whole number of minutes — so the seconds are identical everywhere on earth.
When it is 14:07:23 UTC, it is 09:37:23 in Mumbai and 23:07:23 in Tokyo. Only the hours and minutes differ. UTC right now is —.
Why the seconds always match
Time zones are defined in whole minutes. Most are whole hours; a handful are half-hours (India, UTC+5:30) or quarter-hours (Nepal, UTC+5:45; Chatham, UTC+13:45).
None is offset by a fraction of a minute. So the seconds hand is a global constant, and a world clock showing seconds for six cities is showing the same number six times.
This was not always true. Before standardisation, local mean time was set by the sun and offsets between towns were arbitrary numbers of minutes and seconds — Dublin ran 25 minutes 21 seconds behind Greenwich until 1916. Standardisation rounded all of that away.
So when are seconds useful?
Three cases, and they are narrower than people expect.
Confirming a clock is live. A ticking second tells you the display is updating rather than frozen on a stale value. This is the most common honest reason to want them.
Coordinating a precise moment across places. A launch, a market open, a synchronised release. Here everyone needs the same second, and since seconds are global, any accurate clock works.
Checking your own device's accuracy. Comparing against a known-good source shows whether your machine's clock has drifted — which it does, without network time synchronisation.
Why most world clocks leave them out
Because a grid of cities with ticking seconds is visually noisy and adds no information. The question a world clock answers is "roughly what time is it there, and are they awake" — and that is an hours-and-minutes question.
Interfaces that do show seconds usually do it on a single primary clock rather than on every row, which is the reasonable compromise: one live element to prove the display is running, and calm rows underneath it.
If you need real accuracy
Your device's clock is only as good as its last synchronisation. Phones and computers sync automatically over the network and are typically within a fraction of a second. Devices with network time disabled can drift by seconds a day.
For anything where sub-second accuracy genuinely matters, the answer is a proper time synchronisation protocol against a reference server, not a clock display.
Related: World clock · What is UTC time?
Timezone: World Clock Widget
A world clock, converter and live day/night map for iPhone — 325 cities, offline, no account.
Figures on this page are computed from the IANA time zone database. Last generated 2026-08-18.