chronotype

noun
chro·​no·​type | \ ˈkrō-nə-ˌtīp How to pronounce chronotype (audio) \

Medical Definition of chronotype

: the internal circadian rhythm or body clock of an individual that influences the cycle of sleep and activity in a 24-hour period It is also true that we are increasingly sleeping outside of the times normally dictated by our internal circadian clocks (our "chronotype").Science, 1 June 2012