Research

Adherence

Social Jet Lag (SJL) measures weekly differences in sleep timing (workdays vs. free days) and is insensitive to day-to-day variability.

Use Social Jet Lag (SJL) only if you want to measure the difference between your workday and weekend sleep schedules. Do not use SJL to assess day-to-day consistency, as it will not detect daily fluctuations in sleep timing or duration.

GoodSupportsHIGH confidence
SJL is a measure of weekly but not daily sleep regularity.
Dorothee Fischer et al. · SLEEP · 2021

Why this rating

Demonstrated through simulation scenarios where daily variation was introduced while SJL remained constant.

Source

Measuring sleep regularity: theoretical properties and practical usage of existing metrics

Dorothee Fischer et al. · SLEEP · 2021

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