What time should I go to bed if I wake up at 2:00 pm?

Waking at 2:00 pm is a shift-worker's morning. Five cycles start at 6:15 am, six at 4:45 am — both in daylight, which makes blackout curtains the real bedtime tool.

Why three times and not one

The middle option, 6:15 am, is five cycles and 7 h 30 min of actual sleep; 4:45 am is six cycles and 9 h. Both sit inside the adult range. The 7:45 am option is 6 h: enough to get through the day, not enough to do it twice.

Sleep moves from light sleep into deep sleep and then REM, and one pass takes about 90 minutes — anywhere from 70 to 120 depending on the person and the point in the night. That spread is why these are windows, not appointments.

Walk through the night from a 6:15 am lights-out: asleep by about 6:30 am, into the first stretch of deep sleep around 6:50 am, first REM period near 7:45 am, the halfway point of the night at 10:15 am, and the longest REM period of the night starting around 1:25 pm — which is what a 2:00 pm alarm at the end of cycle 5 lets you finish.

All bedtimes for a 2:00 pm alarm

Formula: bedtime = wake time − (cycles × 90 min) − 15 min · adult range from the NSF 2015 panel and the AASM/SRS 2015 consensus · methodology

If you can't fall asleep by 6:15 am

If 6:15 am comes and your mind is still running, aim for the next cycle boundary at 7:45 am instead of counting the minutes. Ten to twenty minutes to fall asleep is normal; much longer, repeatedly, is worth a conversation with a clinician rather than a calculator.

Try a different time