World clock FAQ: how Time Now Live keeps time accurate

Below are the questions we are asked most often by the people who use Time Now Live every day — traders watching a market open in Tokyo, families calling home, and support teams juggling handover windows across three continents.

Where does the time on this site come from?

Every clock you see is drawn from a single reference timestamp served by our own infrastructure, not from the clock inside your laptop or phone. When the page loads we compare your device clock against that reference and keep the difference in memory, then render each city using the IANA time zone database through the browser's own internationalisation engine. That means a phone running four minutes fast still shows the correct time here, and we tell you on the home page exactly how far off your device is.

Why does my computer show a slightly different time?

Consumer devices drift. A laptop that has been asleep for a weekend, a desktop with a failing CMOS battery, or a phone that lost its network sync can all wander by seconds or minutes. Operating systems correct this quietly in the background, sometimes hours later. We surface the drift instead of hiding it, so you can decide whether to trust the clock in your menu bar for a scheduled call.

Do you handle daylight saving time automatically?

Yes. Offsets are never hard-coded. We resolve each city through its IANA zone identifier — Europe/London, America/Sao_Paulo, Asia/Kolkata — which carries the full historical and current rule set for that region. On the morning a country springs forward, our city pages follow the change to the second, and the page tells you plainly whether daylight saving is in force right now.

How accurate are the sunrise and sunset times?

Sunrise and sunset are computed from the city's latitude and longitude using standard solar position formulas, referenced to the visible upper edge of the sun at the horizon. Expect agreement within about a minute of an official almanac for most locations. Very high latitudes are a special case: during polar day or polar night the sun never crosses the horizon, and we label the day length accordingly rather than inventing a number. Local terrain — a mountain ridge to the east, for instance — can also shift the moment you personally see the sun.

Which cities are included?

More than a million populated places, administrative regions and districts, from megacities down to small towns and named localities. Each one has its own page, its own live clock and its own time zone facts. If you cannot find somewhere, try the search box with the first three or four letters; suggestions appear as you type, and many places are listed under a local spelling.

Can I see the same page in my own language?

Time Now Live is published in ten languages, including Arabic with full right-to-left layout. Use the globe button in the header to switch; the page you are reading stays the same, only the language of the interface and the descriptive text changes.

Is there an API?

Yes — a lightweight time and city lookup endpoint is available for developers who need reference time or time zone data inside their own products. Write to us from the contact page and tell us roughly what volume you expect, and we will send access details.

How often is the city data refreshed?

Place data is rebuilt from open geographic datasets on a regular cycle, and time zone rules are updated whenever the IANA database publishes a new release — usually several times a year, often because a government has changed its daylight saving policy at short notice.