Social jet lag is what happens when your schedule pulls sleep timing sideways.
daygauge treats social jet lag as timing context: a gap between workday and free-day sleep midpoint, not a medical label.
What is social jet lag?
Social jet lag is commonly estimated by comparing the midpoint of sleep on workdays with the midpoint of sleep on free days.
The simple definition
Social jet lag describes a mismatch between the sleep timing your body tends toward and the timing your social or work schedule forces.
The common calculation uses the difference between sleep midpoint on workdays and free days.
A useful app evidence
daygauge should not tell a user they have a disorder. It can say: your weekend sleep midpoint was 92 minutes later than your weekday midpoint.
That evidence is easier to act on than a vague message about being tired or inconsistent.
What to experiment with
A reasonable experiment might be a smaller weekend wake-time shift, earlier outdoor light, or a gentler Sunday evening routine.
daygauge would watch whether the gap narrows and whether sleep timing, movement, and next-day notes improve against baseline.
The useful question is not “do I have social jet lag?”
A more useful question is: when your free-day midpoint moves later, what else moves with it? daygauge can compare next-day movement spread, morning light exposure, energy notes and evening screen timing against your own baseline.
Weekend midpoint moved 96 minutes later. Monday movement started 74 minutes later and bedtime drift continued for two nights. Try a smaller Sunday wake-time shift and check whether timing stabilises next week.
That kind of pattern is more useful than generic advice because it gives the user a lever to test, not a judgement about their lifestyle.
Sources daygauge can cite without overclaiming.
These sources inform product wording and evidence labels. They should not be turned into personal diagnosis, treatment or disease-risk prediction.
- Social jetlag: misalignment of biological and social time
- Social Jetlag and Related Risks for Human Health: A Timely Review
- Chronotype and social jetlag critical review
Research context only. daygauge does not diagnose, treat, prevent or predict disease risk. Personal medical concerns belong with a qualified clinician.
Related daygauge guides.
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