What time should I go to bed if I wake up at 9:00 pm?

For a 9:00 pm alarm the day is your night. Five cycles start at 1:15 pm; the minimum four start at 2:45 pm.

Why three times and not one

The middle option, 1:15 pm, is five cycles and 7 h 30 min of actual sleep; 11:45 am is six cycles and 9 h. Both sit inside the adult range. The 2:45 pm option is 6 h: enough to get through the day, not enough to do it twice.

A cycle is one trip through light sleep, deep sleep and REM. The 90-minute figure is an average from NIH material; your own cycles could run 70 to 120 minutes, so treat each time as the middle of a 15-minute window.

In clock terms: lights out 1:15 pm, asleep around 1:30 pm, deepest sleep of the night between roughly 1:50 pm and 3:00 pm, the night's midpoint at 5:15 pm, and REM building toward 8:25 pm. The 9:00 pm alarm lands as cycle 5 closes, so you are likely in light sleep rather than deep.

All bedtimes for a 9:00 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

9:00 pm: two hours before an 11 pm start, or one night you have to get through

Two kinds of people set a 9:00 pm alarm. The first works nights and sleeps as late as possible: bed at 1:15 pm for five cycles or 11:45 am for six, up at 9:00 pm, at work by 11. The second is not a shift worker at all but has a single night ahead, such as a red-eye flight, a drive that starts at midnight or an on-call night, and wants real sleep banked first instead of a nap.

For the regular, the question is whether two hours is enough runway. Grogginess after a long sleep fades within about half an hour, so it is, provided the commute is short; if you drive forty minutes to an 11 pm start, then the alarm, a meal and the door are a tight fit and the 8:00 pm alarm is the safer one. For the one-off, the difficulty is falling asleep at 1:15 pm when your body expects to be awake. The afternoon dip helps a little. Getting up two or three hours early that morning helps more, and so does skipping coffee after 7:15 am, the six-hour line for this bedtime. If sleep has not come by 2:00 pm, the four-cycle option at 2:45 pm is still six hours, and a 90-minute nap ending near 9:00 pm will carry part of the night. Either way you will have been awake only 10 hours at 7 am.

Every alarm in the 9 pm hour

Lights-out times for each alarm · last coffee = six hours before the five-cycle bedtime (Drake 2013) · full grid on the open data page

If you can't fall asleep by 1:15 pm

Fifteen minutes is the average time a healthy sleeper takes to drop off; ten to twenty is normal. If you are still awake twenty minutes after 1:15 pm, sleep-medicine guidance is to get up, do something dull in dim light, and return when sleepy — lying there teaches the brain that bed is for being awake. Miss the window and the next one, 2:45 pm, is only a cycle away.

Try a different time