During the night; at night. Now chiefly North American colloquial, except in to work nights: to work at night, frequently in addition to a daily…

on night = by night at phrases 2a(b). Cf. a-night, adv. Obsolete.

in (also †of, †on, †upon) the night: by night, during the night.

by night: during the night, in the night-time. by night and (by) day: always, at all times. by night or day: at any time. See by, prep. 19b.

on (also in) nights: by night, esp. usually or habitually. Cf. a-nights, adv. Obsolete.

During the night, at night.

During the night, at night. Cf. nights, adv.

at night: at nightfall, in the evening or night; during the hours of darkness. Frequently designating a specified time.

after nightfall.

At night; during the night. Cf. a nighttimes, adv.

At night; during the night. Cf. a-night, adv.

at nights: in the evenings; by night (esp. usually or habitually). Cf. phrases 2a(c).

At or by night; during the night. Obsolete.

By night, ere night.

By night, during the night.

At night; during the night.

nightly.