festival vs time period

festival and time period both are nouns.

Word	Noun	Adjective	Verb	Adverb
festival	Yes	No	No	No
time period	Yes	No	No	No

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

Other hypernyms of festival include period, period of time.

festival (noun)	time period (noun)
an organized series of acts and performances (usually in one place)	an amount of time
a day or period of time set aside for feasting and celebration