12 hour timer
12 hours
The countdown is running. Your browser will not let a page play sound until you interact with it — tap anywhere to arm the alarm.
- In seconds
- 43,200
- As a fraction of an hour
- 1200%
- Fit in a day
- 2
- ISO 8601
- PT12H
Other timers
About this timer
It keeps time against your device’s clock rather than by counting ticks, so it stays accurate in a background tab, where browsers throttle timers to once a minute or less. Switch away and come back and it will be right.