World Clock
Live current time in cities around the world.
Overview
The World Clock displays the current time in a configurable list of cities, ticking once per second so each clock stays live without you needing to reload. Add zones for the cities you care about — London, New York, Tokyo, Sydney, your distributed teammates' home cities — and pin the tab as a permanent reference.
Useful for support engineers triaging a global on-call rota, remote-first founders running staff across continents, news desks tracking embargo timings, broadcasters scheduling international live segments, travellers staying in touch with home, and finance traders keeping an eye on multiple market opens.
How it works
Each clock is computed by converting the current browser time to the target IANA time zone using the standard Intl.DateTimeFormat API, which reads the same tz database (Olson database) used by every major operating system. DST transitions are handled automatically — when London springs forward in late March or New York falls back in early November, those individual clocks shift while others (Tokyo, Reykjavík) stay put.
Because the API ships with browser-bundled tz data, the clocks reflect the rules in effect at the time the browser was last updated. Outdated browsers may miss recent rule changes (Lebanon's 2023 short-notice shift was a notable example) — keeping the browser up to date keeps the clocks accurate.
Examples
London 2026-05-18 14:23:07 BST (+01:00)
New York 2026-05-18 09:23:07 EDT (−04:00)
Tokyo 2026-05-18 22:23:07 JST (+09:00)
Sydney 2026-05-18 23:23:07 AEST (+10:00)
Mumbai 2026-05-18 18:53:07 IST (+05:30)
FAQ
Why does Mumbai show :53 when others show :23?
India Standard Time is +05:30 — one of several half-hour offsets used around the world. The minutes value differs from zones on whole-hour offsets by 30, and from Nepal (+05:45) by 15.
Will my clocks survive a daylight-saving transition?
Yes. On the morning of a DST transition each affected clock jumps automatically while non-DST zones stay put. The offset shown beside each clock updates accordingly.
Can I add a custom city not in the dropdown?
The IANA tz database covers every official zone. Cities within the same zone share the same time; pick the canonical zone name (for example America/New_York covers Boston, Philadelphia, and Atlanta too).
Does it sync across devices?
The list of zones is stored in the browser's local storage and the URL hash, so you can bookmark a multi-city view and share the link with a teammate.
Why does one of my clocks look slightly off?
Compare your computer's clock against a known accurate source like time.gov. The world clock derives every zone from your local clock, so a local NTP drift propagates to every city in the list.