How do you reset your circadian rhythm?

Short answer: Keep the same wake time every day, get daylight soon after you wake up, and dim the lights in the evening. Regular meals, daytime activity and no caffeine late in the day help too. The body clock moves on average about one to one and a half hours a day, so a large shift takes several days.

How do you know if your circadian rhythm is off?

Common signs are trouble getting to sleep, waking up still tired, and feeling sleepy or unable to concentrate during the day. When circadian rhythms fall out of sync for a short time, drowsiness, poor coordination and difficulty with learning and focus can follow.

Your week can also give a clue. If you sleep much later on free days than on work days, read what social jet lag is.

Why is my body clock messed up?

Light is the strongest signal for resetting the body clock, so light at the wrong times is a common cause of trouble. Typical causes include:

• Bright light late in the evening, from a TV screen, a phone or other bright lights.
• Too little natural daylight during the day.
• Late nights, and bedtimes and wake times that change from day to day.
• Flying across time zones, covered in how long jet lag lasts, and night work, covered in how shift work affects your body clock.

How do you fix your sleep schedule?

Start with a fixed wake time. Get up at the same time every day, and do not sleep in after a bad night. Then use light on purpose and get outdoor daylight soon after waking, because morning light moves the clock earlier and evening light moves it later.

In the evening, dim the lights for a while before bed and cut down on screens. Eat meals at regular times, stay active in the daytime but not close to bedtime, and avoid daytime naps, especially in the afternoon. Stop caffeine early, since the NHS advises no tea or coffee for at least 6 hours before bed.

Melatonin is sometimes used to help shift the clock, but the rules differ by country. In the United States it is sold as a dietary supplement, while in several other countries it is a medicine you can only get through a doctor. Ask a doctor or pharmacist before using it.

Can your circadian rhythm be fixed, and how long does it take?

It can be shifted. Light helps keep the body clock in step with the outside world every day, so a steady daily routine can move it back into line. For circadian rhythm disorders, the most common approaches are lifestyle changes, timed bright light boxes and melatonin.

It takes time, though. After travel across time zones, the body clock adapts on average by about 1.5 hours a day after flying west and about 1 hour a day after flying east, so a flight three time zones east needs roughly three days. Moving earlier is harder for most people, because the internal day is slightly longer than 24 hours.

When should you see a doctor?

See a doctor if changing your habits has not helped, if you have had trouble sleeping for months, or if it makes daily life hard to cope with. A doctor can look for the cause, check for a circadian rhythm sleep disorder and refer you to a sleep clinic if another sleep disorder is suspected. Do not drive when you feel sleepy.

How Actogram looks at this

Actogram reads the daily rhythm of rest and activity from ordinary minute-level step counts from a phone or watch. It is designed for live data that keeps coming in, not only for finished recordings, and it aims to work for irregular days, such as shift work, jet lag and fragmented days. Today its tools are for research and wellness use and do not diagnose, treat or prevent any condition.

Sources

• Circadian Rhythm Disorders, National Heart, Lung, and Blood Institute, 2022
• Circadian Rhythm Disorders: Causes and Risk Factors, National Heart, Lung, and Blood Institute, 2022
• Jet Lag Disorder, CDC Yellow Book 2026, Centers for Disease Control and Prevention, 2025
• Circadian Rhythms, National Institute of General Medical Sciences, 2023
• Insomnia, NHS, 2024
• Melatonin: What You Need To Know, National Center for Complementary and Integrative Health, 2024

General information, not medical advice. If sleep or tiredness problems affect your daily life, talk to a doctor. Reviewed 6 November 2026 by the Actogram team.