good time to view the moon; full moon season
Archaic expression referring to the time when the moon is full and best for viewing. Not used in modern everyday speech.
In the old days, people held banquets when the moon was full.
Compound of 月 (tsuki, 'moon') + の (no, possessive particle) + 頃 (koro, 'time, about'). The exact historical derivation is uncertain; it is an archaic set phrase.