Sleep Pattern Analyzer
Enter your sleep schedule and discover your chronotype, visualize your sleep stages, calculate your social jet lag and find your peak performance windows.
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The Three Human Chronotypes Explained
Chronotype, your biological preference for the timing of sleep and wakefulness, is primarily determined by your genetics. Professor Till Roenneberg at Ludwig Maximilian University in Munich, who coined the term social jet lag, has measured chronotypes in over 200,000 people across Europe. His data shows that human sleep timing follows a normal distribution, with most people falling in the intermediate range and smaller populations at either extreme.
Social Jet Lag, The Hidden Sleep Thief
Social jet lag is the difference between your biological sleep midpoint (when you naturally sleep without social constraints) and your social sleep midpoint (when you actually sleep).
The health consequences are significant and dose dependent. People with 2 or more hours of social jet lag show cognitive profiles similar to people sleeping 2 hours less than they actually do, a paradox that has confused researchers until chronobiology provided the explanation.
The mechanism is circadian misalignment: when you sleep at times that conflict with your internal biological clock, the synchronisation between your master clock in the suprachiasmatic nucleus and the peripheral clocks in your organs, immune system and metabolism breaks down. This desynchronisation impairs virtually every metabolic process that relies on circadian timing, which is most of them.
Frequently asked questions
Can I change my chronotype?
Chronotype has a strong genetic component but can be shifted modestly through behavioural interventions. Morning bright light therapy (10,000 lux for 30 minutes immediately on waking) can advance an evening chronotype by 1 to 2 hours over 3 to 4 weeks. Strict wake time consistency matters more than bedtime for shifting phase. Age also shifts chronotype, it naturally advances (becomes earlier) from around age 20 onwards, accelerating after 50. You cannot completely change your chronotype but you can shift it by 1 to 2 hours with sustained effort.
Is being a night owl unhealthy?
A night owl chronotype is not inherently unhealthy, it is a natural biological variation. The health problems associated with evening chronotypes arise from the mismatch between biological timing and social obligations (work and school starting early), not from the chronotype itself. Research suggests that if society shifted to schedules aligned with natural chronotype diversity, health outcomes for evening types would improve substantially. The problem is social jet lag, not the chronotype.
What is the most accurate chronotype test?
The most clinically validated chronotype assessment is the Munich Chronotype Questionnaire (MCTQ) developed by Till Roenneberg, which asks specifically about sleep timing on free days without alarms. The Morningness Eveningness Questionnaire (MEQ) by Horne and Östberg (1976) is also widely used. Both measure the same underlying construct. Our analyzer uses a simplified version of the MCTQ approach, comparing free day sleep midpoint to social obligation sleep midpoint to calculate both chronotype and social jet lag simultaneously.
How many hours of sleep does an adult really need?
The American Academy of Sleep Medicine and Sleep Research Society recommend at least 7 hours a night for adults. The National Sleep Foundation suggests 7 to 9 hours for most adults and 7 to 8 hours for people 65 and older. Some people need more, and you can judge your own need by how you feel on days you are not sleep deprived.
How do I adjust to daylight saving time?
Move your schedule by 15 to 20 minutes over several days before the change and get morning light afterwards. Expect a few days of adjustment.
Will waking at the end of a cycle remove morning grogginess?
It can help some people, because waking from light sleep is usually easier than waking from deep sleep. The effect is not guaranteed. Grogginess, known as sleep inertia, usually fades within 15 to 30 minutes and also depends on how much sleep you had and when you wake in your body clock.
Is 8 hours too much sleep?
Eight hours sits inside the normal range. If you regularly need 10 or more hours and still feel unrefreshed, mention it to a doctor, because it can be linked with health conditions, medicines or poor quality sleep.
How do I move my bedtime earlier?
Shift it by 15 to 30 minutes every two or three days while keeping the wake time fixed, get bright light after waking and dim lights for an hour before bed.