Set an alarm for 23:21

⏰ The alarm will ring at 11:21 PM — in 21 h 09 min
Alarm at 11:21 PM
⏰ 11:21 PM
21Hours
:
9Minutes
:
34Seconds
Saturday, October 24, 2026

Set an alarm for another time

Best bedtimes to wake up at 11:21 PM

Go to bed atSleep cyclesSleep
2:06 PM69 h
3:36 PM57 h 30 min
5:06 PM46 h
6:36 PM34 h 30 min

Assumes about 15 minutes to fall asleep and sleep cycles of roughly 90 minutes. Cycle length varies from person to person, so treat these as estimates.

Snooze times after a 11:21 PM alarm

Snooze length1st2nd3rd
5 minutes11:26 PM11:31 PM11:36 PM
9 minutes11:30 PM11:39 PM11:48 PM
10 minutes11:31 PM11:41 PM11:51 PM

Nine minutes is the traditional snooze length on many alarm clocks.

About 11:21 PM

11 PM is the last hour of the calendar day; anything due 'by end of day' must be done before midnight.

Press “Start Alarm” and keep this tab open; press “Test Alarm” first to check the volume.

About 11:21 PM

12-hour clock11:21 PM
24-hour clock23:21
Military time2321
In wordsTwenty-one minutes past eleven
Part of the dayNight

Questions about a 23:21 alarm

How do I set an alarm for 23:21?

Open this page, press “Start Alarm” and leave the tab open. The alarm rings at 11:21 PM, which is 21 hours, 9 minutes from now.

What time should I go to bed to wake up at 11:21 PM?

For five full sleep cycles, go to bed around 3:36 PM; for six cycles, around 2:06 PM.