12 hour timer
Plenty of time, clearly counted. Your 12-hour countdown is ready.
Ready
Hours : Minutes : Seconds
Keep this tab open for the alarm.
Related timers
How to use this 12 hour timer
Get started in four simple steps.
Choose your sound
Pick Bell, Chime or Off and use Test sound to check the volume.
Start
Press Start timer when you are ready. Opening this page never starts the countdown by itself.
Pause when needed
Pause and resume at any time. Reset restores the full 12 hours.
Time’s up
At zero the page shows Time’s up and tries to play your alarm for up to 10 seconds.
12 hour timer at a glance
- Total seconds
- 43,200
- Starts at
- 12:00:00
- Half-way mark
- 06:00:00
12 hours is 720 minutes or 43,200 seconds. For timers of several hours, keep the device plugged in and the page open. A browser may pause pages on a sleeping device, so a separate alarm clock is more dependable for very long waits.
Frequently asked questions
Still have a question? Get in touch
How many minutes are in 12 hours?
12 hours is 720 minutes or 43,200 seconds. The timer shows it as 12:00:00 when it is ready to start.
When will a 12 hour timer end?
Exactly 12 hours after you press Start timer. For example, if you start at 3:00 PM it ends at 3:00 AM the next day. While it runs, the finish time is shown under the countdown, and pausing moves it later.
Can I pause the 12 hour timer?
Yes. Pause holds the remaining time and Resume continues from there. Reset returns to the full 12 hours, and asks first while the timer is running.
Will the alarm work if I leave this tab?
Keep the tab open. Switching to another tab is usually fine, but browsers can slow down pages in the background and may block sound that was never enabled. For the best chance of hearing the alarm, keep this page open and visible and press Test sound first. Closing the tab stops the alarm.