The Collaborative International Dictionary
day-and-night
day-and-night \day-and-night\ adj. same as around-the-clock.
Syn: around-the-clock, nonstop, round-the-clock.
WordNet
day-and-night
adj. at all times; "around-the-clock nursing care" [syn: around-the-clock, nonstop, round-the-clock]
Usage examples of "day-and-night".
It wouldn't be long now, and once Mum and Dad weren't involved in this day-and-night frenzy of activity, she could explain everything and they would see to it that the medics gave her the right shot or whatever it was that she needed.
Smell has its advantages: sight is (in a state of nature) dependent on the sun and is to a great extent useless at night, but smell is on day-and-night duty.