Of or belonging to or active during the day.

Roget 138: periodic, periodical; serial, recurrent, cyclical, rhythmical; recurring etc. v.; intermittent, remittent; alternate, every other.    hourly; diurnal, daily; quotidian, tertian, weekly; hebdomadal^†, hebdomadary^†; biweekly, fortnightly; bimonthly; catamenial^†; monthly, menstrual; yearly, annual; biennial, triennial, &c.; centennial, secular; paschal, lenten, etc. regular, steady, punctual, regular as clockwork.    ... show more

Having a daily cycle or occurring every day.