The diurnal dark period
evening, from dusk to dawn, nightfall, twilight, eventide, nighttime, bedtime, midnight, before dawn, the dark hours, obscurity, witching hour, dead of night.
blackness, duskiness, gloom; see darkness 1.
enjoy, have fun, party; see celebrate 3.
"night." YourDictionary, n.d. Web. 16 May 2018. <http://thesaurus.yourdictionary.com/NIGHT>.
night. (n.d.). Retrieved May 16th, 2018, from http://thesaurus.yourdictionary.com/NIGHT
The period of time between sunset and sunrise:
Of or occurring during the night: