Discover Your Chronotype
& Ideal Sleep Schedule
Chronotype is not a preference — it’s a biological trait determined primarily by genetics (CLOCK gene variants) with age being the strongest non-genetic modifier. Eight questions will identify yours.
Your Social Jet Lag
Social jet lag is the mismatch between your biological clock and your required social schedule. Enter your required weekday wake time to see how many hours of misalignment you carry — and what it means for your health.
How Chronotype Changes With Age
6–12 yrs
age 19–21
gradually
for most
earliness
The teenage evening shift is biological, not behavioural. Melatonin onset in adolescents shifts up to 2 hours later than in adults — driven by pubertal hormonal changes. This is why early school start times impose severe social jet lag on teenagers at the developmental stage when their brains are most sensitive to sleep deprivation. The shift gradually reverses through adulthood, with most people returning to morning-leaning schedules by their 60s.
Frequently Asked Questions
Can I change my chronotype?
Chronotype is primarily genetically determined and cannot be fundamentally changed. However, it can be modestly shifted — approximately 1–2 hours — through consistent bright light exposure immediately on waking (suppresses residual melatonin), avoiding blue light in the 2 hours before bed, and strategic melatonin use (0.5mg, 5 hours before desired sleep onset for evening types trying to shift earlier). Attempting to shift more than 2 hours beyond your genetic chronotype is generally ineffective and often counterproductive.
Is being an evening type unhealthy?
Evening chronotype itself is not unhealthy — it is a normal biological variation found in approximately 25% of the population. The health risks associated with eveningness are largely caused by social jet lag: being forced to wake at 6–7am when your biology wants 8–9am. Studies of evening types living on schedules aligned with their biology show health outcomes comparable to morning types. Roenneberg et al. (2012) found the obesity association was mediated by social jet lag, not chronotype per se.