Set an alarm for 23:57

⏰ The alarm will ring at 11:57 PM — in 21 h 58 min
Alarm at 11:57 PM
⏰ 11:57 PM
21Hours
:
58Minutes
:
43Seconds
Saturday, October 24, 2026

Set an alarm for another time

Best bedtimes to wake up at 11:57 PM

Go to bed atSleep cyclesSleep
2:42 PM69 h
4:12 PM57 h 30 min
5:42 PM46 h
7:12 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 11:57 PM alarm

Snooze length1st2nd3rd
5 minutes12:02 AM12:07 AM12:12 AM
9 minutes12:06 AM12:15 AM12:24 AM
10 minutes12:07 AM12:17 AM12:27 AM

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

About 11:57 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 11:57 PM

12-hour clock11:57 PM
24-hour clock23:57
Military time2357
In wordsThree minutes to midnight
Part of the dayNight

Questions about a 23:57 alarm

How do I set an alarm for 23:57?

Open this page, press “Start Alarm” and leave the tab open. The alarm rings at 11:57 PM, which is 21 hours, 58 minutes from now.

What time should I go to bed to wake up at 11:57 PM?

For five full sleep cycles, go to bed around 4:12 PM; for six cycles, around 2:42 PM.