There’s a bedtime story that I think you’ll really like, one that justifies my going to bed early and waking up early, one that I intend to make required reading for my late-night wife so we can spend more hours together.

New research reveals the ideal time to go to bed, or rather, to fall asleep.

Fall asleep between 10:00 p.m. and 11:00 p.m. appears to be ideal, according to a study of 88,000 UK adults published in the European Heart Journal: Digital Health. People who fell asleep before or after that time were markedly more likely to develop heart disease during the multi-year study:

  • Before 10 p.m.: 24% more likely
  • 11 p.m. to midnight: 12% more likely
  • After midnight: 25% more likely

The findings relate to the simple fact that evolution has programmed us to be active during the day and sleep when it’s dark, a pattern that modern lighting and indoor work allow us to break at our peril.

“The body has an internal 24-hour clock, called the circadian rhythm, which helps regulate physical and mental functioning,” explains study author David Plans, Ph.D., a psychology researcher at the University of Exeter in the United Kingdom.

“The results suggest that sleeping early or late is more likely to disrupt the biological clock, with adverse consequences for cardiovascular health.”

Let there be daylight

The prospect of an ideal bedtime doesn’t surprise me. Our deep-seated circadian rhythm is set by darkness, which triggers the brain to produce melatonin, a sleep-inducing chemical, and daylight, which suppresses melatonin production.

Screens and other artificial lights at night disrupt this biological clock, as does a lack of bright outdoor light during the day.

“Our study indicates that the ideal time to sleep is at a specific point in the body’s 24-hour cycle, and deviations can be detrimental to health,” says Plans. “The time of greatest risk was after midnight, possibly because it can reduce the probability of seeing morning light, which resets the biological clock.”

Bedtime prep starts in the morning

Most adults need at least seven hours of sleep to promote good health, although the amount of sleep you need and how your internal clock naturally adjusts can vary considerably.

Other lifestyle habits during the day will greatly affect your ability to fall asleep and get a good night’s sleep. Among the most important tips for sleeping:

Get plenty of physical activity every day.

Eat healthy foods, avoid alcohol, and avoid late-night snacking.

Avoid stressful things like work email, scary movies, or room scrolling at night.

Dim the lights in the house and avoid screens an hour or two before bed.

Have a consistent bedtime.

Sleeping at the perfect time won’t make you instantly superhuman. But by consistently sleeping on a routine schedule, ideally during your newly determined ideal time, you may find that you sleep better and have more energy, and you’re hedging your bets on living a long and healthy life.