- unceasingly; continually: She worked night and day until the job was done.
- a complete difference; completely different: The improvement in her grades after tutoring was like night and day.
Origin of night
British Dictionary definitions for day and night
Word Origin for night
Word Origin and History for day and night
Old English niht (West Saxon neaht, Anglian næht, neht) "night, darkness;" the vowel indicating that the modern word derives from oblique cases (genitive nihte, dative niht), from Proto-Germanic *nakht- (cf. Old Saxon and Old High German naht, Old Frisian and Dutch nacht, German Nacht, Old Norse natt, Gothic nahts).
The Germanic words are from PIE *nekwt- "night" (cf. Greek nuks "a night," Latin nox, Old Irish nochd, Sanskrit naktam "at night," Lithuanian naktis "night," Old Church Slavonic nosti, Russian noch', Welsh henoid "tonight"), according to Watkins, probably from a verbal root *neg- "to be dark, be night." For spelling with -gh- see fight.
The fact that the Aryans have a common name for night, but not for day (q.v.), is due to the fact that they reckoned by nights. [Weekley]
Cf. German Weihnachten "Christmas." In early times, the day was held to begin at sunset, so Old English monanniht "Monday night" was the night before Monday, or what we would call Sunday night.
To work nights preserves the Old English genitive of time. Night shift is attested from 1710 in the sense of "garment worn by a woman at night" (see shift (n.1)); meaning "gang of workers employed after dark" is from 1839. Night soil "excrement" (1770) is so called because it was removed (from cesspools, etc.) after dark. Night train attested from 1838. Night life "habitual nocturnal carousing" attested from 1852.
Idioms and Phrases with day and night (1 of 2)
day and night
see under night and day.
Idioms and Phrases with day and night (2 of 2)
In addition to the idioms beginning with night
- night and day
- night owl
- black as night
- call it a day (night)
- dead of (night)
- different as night and day
- good night
- make a day (night) of it
- ships that pass in the night