Are you a night owl dragging yourself out of bed, or an early bird who can't see what the fuss is about? You've probably been told which of you is doing it right. The early bird, naturally. It has had the proverbs on its side for centuries.
You'll also read that there is one ideal window for sleep, usually 10pm to 6am, and that your circadian rhythm, the internal clock that runs your day, demands it. It's a tidy idea. So let's see if it survives contact with the evidence. Is there a perfect time to sleep, or did someone just like the sound of it?
The proverb gets tested
In 1998, two British researchers did something wonderful. They took Benjamin Franklin's maxim literally. "Early to bed and early to rise makes a man healthy, wealthy, and wise" is a claim about three measurable things, so they measured them.
They used a survey of 1,229 Britons aged 65 and over, followed for 23 years. They called 356 of them larks, in bed before 11 and up before 8, which is hardly heroic. They called 318 of them owls, in bed at 11 or later and up at 8 or later.
The larks weren't richer. The owls had the largest average income and were more likely to have a car. Presumably to get to work late. The larks did no better on a test of mental ability, and they weren't in better health. Both groups had a slightly lower risk of death than the rest, and that was explained by the shorter time they spent in bed.
That was the other finding. The lowest risk of death went with about eight hours in bed. Those who spent 12 hours or more had 70% higher risk than those who spent nine, even after allowing for illness, though long hours in bed may still be a sign of something wrong and not its cause.
One survey of older people doesn't settle anything, but the saying had its chance and didn't take it.
Franklin may not have been entirely serious either. In 1784 he wrote a satirical letter suggesting that Parisians could save a fortune in candles if they would only get up earlier. His plan had some teeth. He proposed a tax on every window with shutters, guards in the candle shops, and a limit of one pound of candles per family per week. Church bells would ring at sunrise, and if that wasn't enough, cannon would be fired in every street "to wake the sluggards effectually". The snooze button seems mild by comparison.
And Win the Morning, Win the Day: Simple Rituals That Separate High Achievers from the Rest has the famous morning routine that he couldn't keep. You can read the plan in his own words in .
Is there a best hour?
The nearest thing to an answer comes from 103,712 people in the UK who wore motion sensors for seven days, so the times didn't rest on anyone's memory. They were followed for nearly six years.
Those who fell asleep between 10 and 11pm had the least heart disease. Falling asleep before 10 went with a 24% higher risk, between 11 and midnight with 12%, and at midnight or later with 25%. Those figures already allow for how long people slept, how irregular their sleep was, and the usual risk factors. The link was stronger in women, and in men only the before-10 group stood out.
Look at what that doesn't say. It doesn't say earlier is better, because the earliest group did about as badly as the latest. It also doesn't say that getting into bed in that hour protects your heart, because it's only a link, and those who sleep at different hours may differ in ways the study couldn't measure. Don't lie awake watching the clock over it. That won't help your heart either.
Is being an owl bad for you?
Here's the awkward part, after all that fun at the proverb's expense. Among 433,268 UK adults followed for about six and a half years, definite evening types had a 10% higher risk of death than definite morning types. They also had more illness of nearly every kind, with 30% higher odds of diabetes and nearly double the odds of psychological disorders.
So the two studies disagree, and they measured different things in different people. But the authors of the larger one offer a likely reason, which is that owls may be paying for the mismatch, living on a clock that their work and social lives won't respect. The hour itself may not be the problem so much as the fight with it. Why You're Still Exhausted Despite Doing Everything Right has that fight on a small scale, the weekend lie-in and what it does to you.
There's a neat natural test of that mismatch. At the edge of a US time zone, neighbours on either side keep the same work and school hours by the clock, but the sun sets an hour later on one side. An extra hour of evening light cost people an average of 19 minutes of sleep, and it went with worse health and lower income per person. They hadn't changed anything. The sun had just arrived later.
One German factory tried fixing the mismatch directly. It stopped giving morning shifts to its latest risers and night shifts to its earliest. Those workers reported longer, better sleep and greater wellbeing on working days, and the gap between body clock and work clock fell by an hour. Stress levels didn't change.
How much of this is up to you?
Less than the proverb suggests. How to Fix Your Sleep and Wake Up Rested, linked below, has the 351 regions of the genome tied to being a morning person. Age moves it too, and Reset Your Body Clock, linked below, has the teenagers whose grades rose when Seattle let their school start later. They weren't lazy. They were on a different clock. Till Roenneberg's is the book on why your clock runs when it does.
Your clock also moves through life. Young children tend to run early, teenagers late, and many older people early again. So if you're waking earlier than you used to, that may be your age and not a fault.
Before the electric light
You may have read that we were built to go to bed with the sun. It's a lovely thought, so researchers went and looked. They put motion sensors on people in three societies living without electric light, the Hadza in Tanzania, the San in Namibia and the Tsimane in Bolivia.
None of them went to sleep near sunset. Sunset was when the evening started. On average they fell asleep 3.3 hours after it, and they usually woke before sunrise. They slept for 5.7 to 7.1 hours a night, which is what was measured and not a target, since those lives are nothing like yours.
They slept nearly an hour longer in winter than in summer, so your sleep needn't look the same all year. In interviews, the San didn't seem to suffer from insomnia, though their lives are hardly a controlled test. Their sleep ran through the part of the night when the air was cooling, and it ended close to the coldest point.
Then there is the best finding of the lot. When the Hadza were tracked for 20 days, all of them were asleep at the same moment for just 18 minutes in total. On a typical night, a median of eight were awake at any time. Some turned in early, others stayed up, and the pattern followed age. The researchers suggest this may have been useful, because a camp of mixed ages, with some early and some late, always had somebody listening for trouble.
So your owl may have had a job once.
What does matter
Regular hours beat perfect ones. How to Fix Your Sleep and Wake Up Rested has the study of 60,977 adults, in which those with the steadiest hours had a 20 to 48% lower risk of dying during follow-up than those with the most erratic ones, and that's a link as well. It says nothing about what time you pick.
Time since waking may count for more than the clock. When athletes were tested through the day, the best predictor of their peak was how long they'd been awake, and not the time of day. Their performance swung by as much as 26% in a single day, and larks and owls peaked at different times. So if you have something hard to do, count from when you got up.
One hour is enough to show the point. 7 Ways to Make Every Day Work Better — Starting With What Your Body Is Doing has what the spring clock change did to heart attacks in Michigan hospitals.
Finding your own window
Run the free test. On a stretch of days with no alarm, go to bed when you feel sleepy and get up when you wake. The first few nights will be catching up, so look at the last ones. That's your clock talking. Your body usually does tell you, and pushing past that first wave of sleepiness tends to make the night harder.
Keep a record. Note when you went to bed, when you got up and how you felt. Chronic Insomnia: Why Trying Harder Keeps You Awake has what to do with it if sleep has become a real problem.
Fix the wake-up time first. Then keep it, weekends included. How to Fix Your Sleep and Wake Up Rested has why you count backwards from there.
After a late night, get up anyway. Keep the usual wake-up time and go to bed when you're sleepy that evening. A long lie-in pushes your clock later and makes the next night harder.
Move it slowly if you must. If your life needs you up earlier than your clock likes, shift your bedtime by about 15 minutes every few nights. Reset Your Body Clock has what speeds it up, starting with morning light and earlier meals.
If you work nights, you have less choice. The same ideas apply, flipped to suit your own day: the same hours as far as you can keep them, a dark room, and light when your day starts. The cancer agency of the World Health Organization classes shift work that disrupts the body clock as probably carcinogenic, so take it seriously.
Stop the caffeine. The usual advice is to avoid it close to bedtime, and that's far too generous. Boost Your Energy Naturally: Alternatives to Caffeine has the test in which a strong coffee, drunk six hours before going to bed, still cost people more than an hour of sleep. Water, as ever, is the better drink.
Skip the nightcap. A drink may knock you out sooner, but the second half of your night pays for it. The Stress-Sleep Vicious Cycle: How to Break It has that bill in full.
Don't fear the evening workout. The old warning doesn't hold up well. How to Fix Your Sleep and Wake Up Rested has the 23 tests behind that, and the one exception, which is hard exercise finishing within an hour of bed.
Keep the room cool, dark and quiet. Those pre-industrial nights were cooling all the way through, and modern bedrooms aren't. Why You Haven't Slept Your Best Night Yet (And How to Change That Tonight) has the free part first. For the dark part, are the simple fix.
If you share a bed with the other kind. Agree the terms. The owl comes to bed in the dark and leaves the phone outside. The lark gets up without the big light and without the conversation.
Put the phone somewhere else. Blue light takes most of the blame, and Eye-Opening Benefits of Unplugging: How Taking Breaks from Screens Can Transform Your Life has why that's shakier than it sounds. The phone still gets you, because it's so hard to stop.
Keep the routine dull. A book or a few slow breaths will do. It only needs to be the same thing, in the same order, so that your body knows what comes next. Your body is not hard to bore.
Know when it isn't about timing. If loud snoring, pauses in your breathing or falling asleep in the daytime are part of the picture, no bedtime will fix that, and it's worth getting checked. Ways to Stop Snoring Naturally—Which One Will Work for You? is the place to start.
The best time
Sleep is not a luxury, and it isn't a competition either. There's no good evidence for a single perfect hour, and a late bedtime is no moral failing. What the evidence does favour is a time that suits your clock and that you can keep.
Tonight, write down the moment you first feel sleepy. Tomorrow, write down when you woke. That's the start of your own answer, and Franklin never got that far.
Want the whole routine, from alarm to lights out? How to Fix Your Sleep and Wake Up Rested: Complete Guide to Better Sleep — the grogginess, how much you need, the alarm, morning and evening, and the bedroom.
Clock running later than your life allows? Reset Your Body Clock: Sleep Hacks, Tested — morning light, warm feet, eating early, amber glasses and melatonin.
Know an early riser who won't stop mentioning it? Send them this, and mention the income figures.
Disclaimer: This article is general information. For advice about your own health, talk to a qualified health professional.
Affiliate Disclosure: This article contains affiliate links. As an Amazon Associate, All For Life earns from qualifying purchases, at no extra cost to you. We only link to products we would recommend without the commission.
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