chronotype
noun
chro·no·type
| \ ˈkrō-nə-ˌtīp
\
\
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