Bedtimes
You are going to bed at 1:00am. When should the alarm be?
One in the morning is a late bedtime by any reading, and whether it is a problem comes down to a single question: what time does the alarm go off? Everything else about this hour is downstream of that answer.
In short
If you go to bed at 1:00am, set your alarm for 8:45am. 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. 10:15am gives you 9h and 7:15am still leaves you 6h.
- Alarm for a full night
- 8:45amAlarm 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 | 10:15am | 9h | Nine hours. Worth it if you are paying back debt, and more than most adults need every night. |
| 5 | 8:45amAim here | 7h 30m | The target most adults should hold on a normal week. |
| 4 | 7:15am | 6h | Six hours. Short, but a whole number of cycles, so you surface from a lighter patch. |
| 3 | 5:45am | 4h 30m | An emergency night. Fine occasionally, damaging as a pattern. |
The hour where the arithmetic gets unforgiving
From 1am, a full seven and a half hours of sleep finishes at 9:45am. There is no arrangement of cycles that makes a 7am alarm anything other than a short night: it is about five and three quarter hours of sleep, which is closer to four cycles than five and well under the adult consensus figure.
That is worth stating flatly because 1am bedtimes are usually defended on the grounds that the person functions fine. Functioning is a poor instrument. People are reliably bad at judging their own impairment from short sleep, which is exactly why the recommendation is expressed as hours rather than as how you feel.
- From 1am, five cycles lands at 9:45am and four at 8:15am
- A 7am alarm on a 1am bedtime is under six hours of sleep
- Self-assessed alertness is not a reliable guide to how short sleep is affecting you
Measure the night before you judge it
The thing most people get wrong about a 1am bedtime is not the hour, it is the assumption that lights out equals asleep and that the night ran unbroken. Neither is usually true, and both are invisible from the inside: nobody remembers the wake-ups that lasted under a couple of minutes, and almost everybody underestimates how long they took to drop off.
A phone on the nightstand can settle both without any hardware. It is estimating rather than measuring, which is a real limitation and one worth knowing, and it is still the difference between a number and a guess.
What that estimate is and is not is set out at /blog/what-estimated-sleep-stages-really-mean.
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 8:45am 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,8:45am 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 1am?
Five sleep cycles puts the alarm at 9:45am, which is seven and a half hours of sleep. Four cycles is 8:15am at six hours, and three is 6:45am at four and a half. All include fifteen minutes to fall asleep.
Is 1am to 7am enough sleep?
It is under six hours of actual sleep, which is below the seven or more hours the American Academy of Sleep Medicine gives for adults. It is fine as an occasional night. Repeated across a working week it is a deficit, and one that a weekend lie-in does not fully clear.
Why do I feel fine on six hours of sleep?
Because the sense of feeling fine is one of the things short sleep affects. Performance declines measurably while self-rated alertness flattens out, so you stop noticing the deficit before you stop having it. A genuinely small number of people are short sleepers, and it is far smaller than the number who believe they are.
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 12:00amWhere to put the alarm after a 12:00am lights-out.
- Going to bed at 12:30amWhere to put the alarm after a 12:30am 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.
- 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.
- FeaturesStreaksTock counts a night toward your streak at 90% of your sleep goal, and it bridges one missed night per week automatically. Milestones sit at 3, 7, 14, 30, 60, 100, 180 and 365 nights, drawn as a moon rather than a flame.
- Sleep soundsRainfallSteady rainfall spreads its energy fairly evenly across the audible range, close enough to pink noise that it masks about as well while sounding a great deal less like a machine. The bigger variable is the surface: rain on canvas, on glass and on a car roof are three genuinely different sounds, and only one of them will suit your room.
- Tock for youNight owlsYou are wide awake at 1am and useless at 7am, and every piece of advice you have ever read starts with going to bed earlier, which you have done, repeatedly, while staring at the ceiling.
- AlternativesTock vs PzizzKeep Pzizz if you nap, or if your mind needs words to hold onto while you fall asleep. Tock generates its sound too, but it has no voiceover and nothing for naps. What Tock adds is the alarm, the tracking and the morning report Pzizz does not attempt.
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 8:45am for a lighter moment and rings then, and your set time is always the fallback.