Social jet lag: Sleep-corrected formula.

Social jet lag is a term describing misalignment between social and biological times. In this article, it is argued that the currently used formula for social jet lag captures not only this misalignment, but also sleep debt resulting from sleep deprivation during workdays. It is proposed to adopt the sleep-corrected formula for social jet lag, which takes the form of the difference between the sleep onset on free days and workdays in the case of subjects with longer sleep and later (or equal) sleep onset on free days compared to workdays; it takes the form of the difference between the sleep offset on free days and workdays for subjects with longer sleep and earlier (or equal) sleep offset on workdays compared to free days.