Platonic month

noun

(astronomy, astrology) One twelfth of a Great Year, corresponding to one of the zodiacal ages (roughly 2000 years).

The Platonic month is a period of time used in astronomy.

意味（1）

(astronomy, astrology) One twelfth of a Great Year, corresponding to one of the zodiacal ages (roughly 2000 years).

Sumerian civilization lasted for an entire Platonic month from 4000 to 2000 B.C.