"Night" [ nahyt ]
noun
1. the period of darkness between sunset and sunrise.
Also, an evening used or set aside for a particular event, celebration, or other special purpose (sometimes initial capital letter); e.g., a night on the town; poker night; New Year's Night.
Word origin:
First recorded before 900; Middle English.
Old English niht (West Saxon neaht, Anglian naeht, neht) "the dark part of a day; the night as a unit of time; darkness," also "absence of spiritual illumination, moral darkness, ignorance".
From Proto-Germanic nahts (source also of 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" (source also of Greek nyx (stem nykt-) "a night," Latin nox (stem noct-), Old Irish nochd, Sanskrit naktam "at night," Lithuanian naktis "night," Old Church Slavonic nosti, Russian noch', Welsh henoid "tonight").
Ancient Egyptians imagined the sky to be the star-spangled body of the goddess Nut, arching over the land. The name of Nut, became Greek nyx, Latin nox and Noct.
from: https://digitalthought.info/awo2.html
The fact that the Aryans have a common name for night, but not for day, is due to the fact that they reckoned by nights.
Thus, in Old English combinations, night was "the night before (a certain day or feast day)". 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, and saeterniht was "Friday night." The Greeks, by contrast, counted their days by mornings.
from: https://www.etymonline.com
