Where “now” comes from
Every clock on this page is your device clock converted to each zone. Nothing is synchronised with an external time server, so if your computer is two minutes slow, all clocks are two minutes slow. On most devices the operating system keeps the clock accurate automatically.
Browsers slow down timers in background tabs. The clocks pause while the tab is hidden and re-read the device clock as soon as you come back, so they never show a stale time as current.
Next clock change
Each named zone shows the next offset change in the rules your browser has today. Governments sometimes change these rules at short notice; a change announced after your browser’s data was updated will not appear.