A two hour timer

This page starts counting 2 hours the moment it opens, and makes a sound when it finishes. Nothing to set, and nothing to press first.

What people set 2 hours for

An exam, a long bake, a film with an interval, or a parking meter you must not forget.

Worth knowing

Two hours is where a single browser tab stops being enough on its own: set this, and set something that will still reach you if the tab is closed.

Questions

Do the timers keep running if I switch tabs?

Yes. The countdown is measured against a monotonic clock rather than counted in ticks, so a backgrounded tab, a throttled timer or a laptop lid closing does not lose time — when you come back it shows what it should, not what it managed to count.

Does a timer survive a daylight-saving change?

Yes, and the distinction matters. A countdown measures elapsed real time, so a timer set for six hours across a spring-forward still runs six real hours even though the wall clock advances seven. An alarm set for a wall-clock time does the opposite: it fires when the clock says so, which is what you want from an alarm.