canicular days vs time period

canicular days and time period both are nouns.

Word	Noun	Adjective	Verb	Adverb
canicular days	Yes	No	No	No
time period	Yes	No	No	No

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

canicular days: the hot period between early July and early September; a period of inactivity
time period: an amount of time

Other hypernyms of canicular days include period, period of time.

canicular days (noun)	time period (noun)
the hot period between early July and early September; a period of inactivity	an amount of time