daylight vs period of time

daylight and period of time both are nouns.

Word	Noun	Adjective	Verb	Adverb
daylight	Yes	No	No	No
period of time	Yes	No	No	No

As nouns, period of time is a hypernym of daylight; that is, period of time is a word with a broader meaning than daylight:

daylight: the time after sunrise and before sunset while it is light outside
period of time: an amount of time

Other hypernyms of daylight include period, time period.

daylight (noun)	period of time (noun)
light during the daytime	an amount of time
the time after sunrise and before sunset while it is light outside