⏳ 12 Hour Timer

Half a day on the clock, counted down to the second.

12:00:00

Tip: click anywhere on the page at least once so the alarm sound can play when time is up.

What is a 12 hour timer good for?

Twelve hours is a full 12-hour work shift, a common intermittent-fasting window, or half a day of travel. Set it once and the alarm marks the exact moment it's over.

Frequently Asked Questions

Is this accurate for something as long as 12 hours?

Yes — it's based on your device's real-time clock, so the alarm fires at the exact end time regardless of how long the countdown runs.

Can two people track the same 12-hour window on different devices?

Yes — each device runs its own countdown, so start it at the same moment on each and they'll ring together.

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