Sleep as Android watches your sleep pattern trends and can tell you your chronotype, social jet lag and much more.
Chronotype is a term used to characterise your sleep patterns. It is a spectrum ranging from 100% night owl to 100% morning lark. Your currently detected chronotype is always shown in the left menu if you have at least 6 months of sleep data.
Night owl tends to stay up active until late night, usually past midnight, and wake up later. See wikipedia article.
Morning lark is named after a bird who rises very early in the morning. A human lark is a person who usually gets up early and feels most energetic towards the start of the day. They tend to get tired towards the evening. See wikipedia article.
You can also see your actual chronotype and chronotype trend in the Charts.
Social jet lag
Social jet lag is a term pioneered by Dr. Till Roenneberg in his book Internal Time. It describes a notion that when people have a completely free day, they will turn to their natural chronotype. But when they work a fixed schedule, they have to fight this natural tendency on workdays. This constant shifting of sleep pattern between workdays and weekdays creates a certain tension that can be best compared to a periodic shifting of timezones – and a jet lag results.
Sleep as Android does not actually use the normal definition of workdays and weekdays, but compute „work-like days“ and „weekend-like days“ from your historical data.
You can also see your actual social jet lag in the Charts.
Generally it is advised to sleep regularly – go to sleep at the same time every day and sleep for a fixed period of time.
Sleep as Android tracks your sleep regularity and shows you in Charts how irregular your sleep is.
The irregularity shown is the variance of your mid sleep hour.