calendar week vs time period

calendar week and time period both are nouns.

Word	Noun	Adjective	Verb	Adverb
calendar week	Yes	No	No	No
time period	Yes	No	No	No

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

calendar week: a period of seven consecutive days (usually reckoned to be from Sunday to Saturday, or from Monday to Sunday)
time period: an amount of time

Other hypernyms of calendar week include period, period of time.

calendar week (noun)	time period (noun)
a period of seven consecutive days (usually reckoned to be from Sunday to Saturday, or from Monday to Sunday)	an amount of time