How to Fix a Broken Sleep Schedule and Reset Your Body Clock

Why schedules drift late

The human body clock runs slightly longer than 24 hours on average, so without daily cues it tends to drift later. Evening light from screens and indoor lighting pushes it later still, and sleeping in on weekends reinforces the delay. Teens and young adults are especially prone to late schedules.

Step 1: choose a wake time and keep it

Pick the wake time you need, then hold it every day, including weekends. Your wake time is the strongest anchor you control. It is fine to start with a wake time a little later than your goal and move it earlier by 15 to 30 minutes every few days.

Step 2: get light immediately

Within the first hour after waking, get outdoor light for 15 to 30 minutes or sit by a bright window. Morning light shifts your clock earlier. Avoid dark sunglasses during that time unless you need them for safety.

Step 3: dim your evenings

From 2 hours before your target bedtime, dim the lights, avoid bright overhead lighting and reduce screen brightness. Put devices away 30 to 60 minutes before bed. Darkness in the evening allows melatonin to rise earlier.

Step 4: go to bed when sleepy, not by force

In the first few days you may not feel sleepy at your target bedtime. Lying awake for hours makes things worse. Go to bed when sleepy, and let the fixed wake time and morning light pull your sleepiness earlier over the following days.

Step 5: support the shift

• No naps, or one short nap before 3pm.
• No caffeine after noon while you are resetting.
• Eat meals at regular times, with breakfast soon after waking.
• Exercise in the morning or early afternoon, ideally outdoors.

Some people use low-dose melatonin in the early evening to help shift the clock earlier. Timing is important, so ask a pharmacist or doctor before trying it.

How long it takes, and when to get help

Expect it to take 1 to 2 weeks or more, depending on how far you need to shift. If you have always found it nearly impossible to fall asleep before very late hours, even with good habits, you may have delayed sleep-wake phase disorder. A sleep specialist can help with carefully timed light therapy and melatonin.