Most sleep advice starts with a number. Get seven to nine hours. But researchers increasingly are studying another dimension of healthy sleep—not simply how long people snooze, but how predictably they do it. A 2026 perspective published in the journal Sleep describes research on sleep regularity as a rapidly growing field, although important questions remain.
Sleep regularity describes the day-to-day consistency of a person’s sleep and wake patterns. Someone who generally goes to sleep and wakes within similar windows has more regular sleep than someone whose schedule moves by several hours from one day to the next.
That distinction matters, because irregular patterns of light exposure, activity, meals, and sleep can disrupt the body’s circadian rhythms, according to researchers writing in Sleep.
The other sleep score
Researchers can measure consistency with the Sleep Regularity Index, which compares a person’s sleep and wake patterns from one day to the next. A score of 100 represents perfectly regular patterns, while zero represents completely random ones. The calculation also considers naps, nighttime awakenings, and changing sleep and wake times, according to research published in Sleep.
A large study used more than 10 million hours of movement data from 60,977 UK Biobank participants. Compared with the least-regular sleepers, those with more consistent patterns had a 20%–48% lower risk of death from any cause during the study period. In this group, sleep regularity was a stronger predictor of mortality risk than sleep duration.
That doesn’t mean anyone should trade eight hours of sleep for five perfectly punctual ones. Sleep duration and quality still matter, and researchers are continuing to study how much variation is unhealthy and how regularity affects different people.
The one-hour idea
After analyzing the patterns, the study’s authors suggested aiming to fall asleep and wake up within one-hour windows each day as a practical way to improve regularity. They noted that waking during the night, fragmented sleep, and naps also influence a person’s score.
The U.S. National Heart, Lung, and Blood Institute similarly recommends maintaining the same general schedule every day and limiting the difference between weeknights and weekends to about an hour.
For many people, that doesn’t require a bedtime enforced with stopwatch precision, but it may mean establishing a few reliable anchors:
Put your sleep on repeat
- Keep the morning steady. Try to wake at approximately the same time, including on days off.
- Don’t let the weekend become another time zone. A modest sleep-in creates less disruption than shifting the entire schedule by several hours.
- Give bedtime a familiar lead-in. Use the final hour before bed for quieter activities and less bright artificial light.
- Start the day with some daylight. Time outside and regular daytime activity can help reinforce daily rhythms.
- Protect your sleep environment. A quiet, cool, dark bedroom supports both consistent timing and good-quality sleep.
These recommendations are included in the National Heart, Lung, and Blood Institute’s guidance on healthy sleep habits.
Of course, shift workers, new parents, caregivers, and others can’t always control their schedules. The goal here isn’t perfect punctuality, nor is this just another reason to worry about sleep. It’s simply to make sleep timing more predictable where and when life allows.
