Bedtimes
You are going to bed at 12:00am. When should the alarm be?
Midnight is the bedtime that sounds late and is only actually late relative to your alarm. Held against a nine o clock start it is unremarkable. Held against a seven o clock one it is a six hour night dressed up as a normal schedule.
In short
If you go to bed at 12:00am, set your alarm for 7:45am. That is 7h 30m of sleep across 5 full cycles, plus the fifteen minutes it takes most people to actually fall asleep, so you wake at the end of a cycle rather than inside one. 9:15am gives you 9h and 6:15am still leaves you 6h.
- Alarm for a full night
- 7:45amAlarm for a full night5 cycles, 7h 30m asleep
- Length of an average sleep cycle
- 90 minLength of an average sleep cycleReal ones run 70 to 120
- Added before the first cycle
- 0h 15mAdded before the first cycleMost calculators forget this
| Cycles | Set the alarm | Time asleep | What it is good for |
|---|---|---|---|
| 6 | 9:15am | 9h | Nine hours. Worth it if you are paying back debt, and more than most adults need every night. |
| 5 | 7:45amAim here | 7h 30m | The target most adults should hold on a normal week. |
| 4 | 6:15am | 6h | Six hours. Short, but a whole number of cycles, so you surface from a lighter patch. |
| 3 | 4:45am | 4h 30m | An emergency night. Fine occasionally, damaging as a pattern. |
Late is a relationship, not an hour
There is nothing intrinsically worse about sleeping from midnight to eight than from ten to six. Total sleep and regularity are what matter, and both of those are indifferent to where the block sits, provided the room is dark and the schedule holds. Plenty of people with genuinely late body clocks do better on this than they ever did trying to be morning people.
What makes midnight expensive is the collision with a morning that was set by somebody else. School and work start times were not designed around chronotype, and for a genuine evening type they function as a permanent early alarm. That mismatch has a name and it is measurable.
- From midnight, five cycles lands at 8:45am and four at 7:15am
- Midnight to 8am is a complete night; midnight to 6:30am is not
- If you have always been like this rather than recently, it is more likely a chronotype than a habit
The persona page for night owls at /for/night-owls covers working with a late clock rather than against it.
Do not fix a late clock by shortening the night
The commonest response to a midnight bedtime and a seven o clock alarm is to keep both and absorb the difference, which turns a chronotype mismatch into chronic short sleep. The two problems are not the same and the second one is worse.
If the morning cannot move, the evening has to, and the only reliable lever on that is light: bright and early after waking, dim and late in the evening. If neither end can move, the honest answer is that the schedule is short and the thing to protect is consistency and the quality of the hours you do get.
The gap between the clock you have and the week you are given is set out at /glossary/social-jetlag.
The table is an average, and your night is not
Ninety minutes is the number everybody quotes because it is roughly the mean. A real night does not run to it. Your first cycle tends to be short, the middle ones stretch, and by the last couple of hours you are cycling faster with more of each one spent in light sleep and REM. So the arithmetic above gets you to approximately the right alarm, and then the last half hour is a coin toss.
That coin toss is the entire argument for a smart alarm, and it is why this page ends with one rather than with a schedule. Tock spends the thirty minutes before 7:45am watching for the moment you are already stirring, on two channels: movement from the accelerometer and sound from the microphone. When it finds one it rings a little early. When it does not,7:45am rings exactly as you set it, so the fallback is never worse than a normal alarm. You can read the mechanism at how smart wake works, or start with sleep cycles explained if the arithmetic itself is the part you want to understand properly.
Questions people ask
What time should I wake up if I go to bed at midnight?
Five full sleep cycles puts the alarm at 8:45am, which is seven and a half hours of sleep. Four cycles is 7:15am at six hours. Both add fifteen minutes for falling asleep after the light goes off.
Is going to bed at midnight bad for you?
Not by itself. What matters is how much sleep follows it and how steady the schedule is. Midnight to 8am, held consistently in a dark room, is a complete night. Midnight to 6am, five nights a week, is a six hour habit and that is the part worth worrying about.
Is midnight to 6am enough sleep?
It is roughly five and three quarter hours of actual sleep, which is under the seven hour figure the American Academy of Sleep Medicine gives for adults. It is fine occasionally. As a weekday pattern it accumulates, and the debt does not clear on one long weekend lie-in.
Other bedtimes
The same arithmetic, run from a different lights-out.
- Going to bed at 8:00pmWhere to put the alarm after a 8:00pm lights-out.
- Going to bed at 8:30pmWhere to put the alarm after a 8:30pm lights-out.
- Going to bed at 9:00pmWhere to put the alarm after a 9:00pm lights-out.
- Going to bed at 9:30pmWhere to put the alarm after a 9:30pm lights-out.
- Going to bed at 10:00pmWhere to put the alarm after a 10:00pm lights-out.
- Going to bed at 10:30pmWhere to put the alarm after a 10:30pm lights-out.
- Going to bed at 11:00pmWhere to put the alarm after a 11:00pm lights-out.
- Going to bed at 11:30pmWhere to put the alarm after a 11:30pm lights-out.
- Going to bed at 12:30amWhere to put the alarm after a 12:30am lights-out.
- Going to bed at 1:00amWhere to put the alarm after a 1:00am lights-out.
- Going to bed at 1:30amWhere to put the alarm after a 1:30am lights-out.
- Going to bed at 2:00amWhere to put the alarm after a 2:00am lights-out.
- Going to bed at 3:00amWhere to put the alarm after a 3:00am lights-out.
Elsewhere on the site
A different corner of the same problem.
- RoundupsThe best alarm apps for shift workersFor shift workers the most reliable alarm is still the iPhone Clock app, because it makes no assumptions about your schedule and lets you keep a saved alarm for every shift pattern. Tock is the better pick if you also sleep in the daytime and need something that will not let you turn it off half asleep at 4pm.
- Wake timesWaking up at 8:30amBedtimes by sleep cycle for a 8:30am alarm.
- Sleep by ageHow much sleep adults needThe American Academy of Sleep Medicine recommends that adults sleep 7 or more hours per night on a regular basis to promote optimal health. It is expressed as a minimum rather than a range because the evidence supports a lower bound far more firmly than it supports an ideal figure.
- NapsThe coffee napA coffee nap means drinking caffeine and then immediately napping for about 20 minutes. Caffeine takes roughly 20 to 30 minutes to have a noticeable effect, so it does not stop you falling asleep quickly, and you wake as it takes hold. The two effects add rather than cancel.
- Wake tonesSunrise alarmA sunrise alarm clock is a bedside lamp that brightens over roughly 20 to 30 minutes before your set time, and the light is the part you are paying for. Tock is an iPhone app with no light hardware at all, so it takes the timing half instead: a soft wake tone rung at a lighter moment inside the last 30 minutes rather than at a fixed time.
- Head to headAutoSleep vs Sleep CycleIf you already wear an Apple Watch to bed, AutoSleep reads a night that Sleep Cycle can only estimate from the room. If you don't own a Watch and don't want one, Sleep Cycle is the only one of the two that works, and it's your alarm as well.
Tomorrow, you wake up just before your alarm
Setting the alarm on a cycle boundary is arithmetic and your night is not. Tock watches the half hour before 7:45am for a lighter moment and rings then, and your set time is always the fallback.