Set Alarm for 5:40 AM

The form is pre-filled for 5:40 AM — hit Set Alarm to start the live countdown. Pick a sound, add a label, and the alarm will ring at 5:40 AM local time.

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No alarm set

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Set an alarm to start

How long until 5:40 AM?

5:40 AM is 05:40 in 24-hour time (0540 in military notation) — the morning. The alarm counts down to the next 5:40 AM in your local time zone, rolling over to tomorrow if it has already passed today.

When to go to bed for a 5:40 AM alarm

Sleep runs in cycles of roughly 90 minutes, and waking at the end of a cycle usually feels easier than being pulled out of deep sleep halfway through one. Allowing about 15 minutes to fall asleep, these bedtimes line up with a 5:40 AM wake-up:

8:25 PM 6 cycles · 9 h of sleep

9:55 PM 5 cycles · 7 h 30 min of sleep

11:25 PM 4 cycles · 6 h of sleep

12:55 AM 3 cycles · 4 h 30 min of sleep

Adults generally need 7–9 hours, so five or six cycles (highlighted) suit most people. Treat these as a starting point — cycle length varies from person to person and through the night.

Hours of sleep by bedtime

In bed at	Sleep before 5:40 AM	Sleep cycles
7:40 PM	9 h 45 min	6.5
8:10 PM	9 h 15 min	6.2
8:40 PM	8 h 45 min	5.8
9:10 PM	8 h 15 min	5.5
9:40 PM	7 h 45 min	5.2
10:10 PM	7 h 15 min	4.8
10:40 PM	6 h 45 min	4.5
11:10 PM	6 h 15 min	4.2
11:40 PM	5 h 45 min	3.8
12:10 AM	5 h 15 min	3.5
12:40 AM	4 h 45 min	3.2

Highlighted rows give the 7–9 hours recommended for adults; ✓ marks a whole number of 90-minute cycles.

Nearby alarm times

5:10 AM Set alarm → 5:20 AM Set alarm → 5:30 AM Set alarm → 5:50 AM Set alarm → 6:00 AM Set alarm → 6:10 AM Set alarm →

Keep this tab open and your device awake for the alarm to ring — how browser alarms work. Need a duration instead of a clock time? Use the timer, or a 20-minute power-nap timer.