nighttime vs night

nighttime and night both are nouns.

Word	Noun	Adjective	Verb	Adverb
nighttime	Yes	No	No	No
night	Yes	No	No	No

As nouns, nighttime and night are synonyms defined as:

nighttime and night: the time after sunset and before sunrise while it is dark outside

Other synonyms of nighttime include dark.

nighttime (noun)	night (noun)
the time after sunset and before sunrise while it is dark outside	darkness
	the time after sunset and before sunrise while it is dark outside
	a period of ignorance or backwardness or gloom
	the dark part of the diurnal cycle considered a time unit
	the time between sunset and midnight
	the period spent sleeping
	a shortening of nightfall