15 Hour Timer

Free online 15 Hour Timer: starts on load, keeps counting while you switch tabs and sounds an alarm when the time is up.

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Input Data

Hours

Minutes

Seconds

When Timer Ends

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Timer

30 seconds

00:00:00

Set the timer for the specified time
1 Minute Timer	40 Minutes Timer	60 Seconds Timer
3 Minutes Timer	45 Minutes Timer	90 Seconds Timer
5 Minutes Timer	60 Minutes Timer	1 Hour Timer
10 Minutes Timer	10 Seconds Timer	2 Hours Timer
15 Minutes Timer	20 Seconds Timer	4 Hours Timer
20 Minutes Timer	30 Seconds Timer	8 Hours Timer
30 Minutes Timer	45 Seconds Timer	10 Hours Timer

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15 Hour Timer

Last updated: July 21, 2026

Illustration for 15 Hour Timer

This is a ready-made 15 Hour Timer — it starts the moment the page opens, so there is nothing to set. It keeps running in a background tab and plays your chosen sound when the time is up. Pick another duration below, or set your own on the full timer.

Ready-Made Presets

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