Platonic year vs time period

Platonic year and time period both are nouns.

Word	Noun	Adjective	Verb	Adverb
Platonic year	Yes	No	No	No
time period	Yes	No	No	No

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

Platonic year: time required for one complete cycle of the precession of the equinoxes, about 25,800 years
time period: an amount of time

Other hypernyms of Platonic year include period, period of time.

Platonic year (noun)	time period (noun)
time required for one complete cycle of the precession of the equinoxes, about 25,800 years	an amount of time