diurnal

constantly day-to-day everyday often periodic regular regularly routine

common commonplace ordinary

circadian cyclic day after day day by day from day to day once a day once daily per diem quotidian

abnormal different irregular uncommon unusual variable

extraordinary infrequent rare

nightly nocturnal

durable enduring long-lasting perpetual stable

everlasting invariable perennial set

abiding changeless continual fixed for keeps forever forever and a day immutable imperishable in for the long haul indestructible perdurable perduring persistent set in concrete set in stone steadfast unchanging unfading

temporary

changing

ephemeral