Japan has a moon-viewing night for the moon that isn't full yet, and attending only one of the two was considered rude.

Jūgoya is the famous fifteenth-night harvest moon; jūsanya, the thirteenth night of the following lunar month, honours the slightly imperfect one. Going to one and skipping the other was katami-tsuki, a one-sided moon, and thought to invite bad luck. An entire festival built on refusing to be satisfied by the obvious answer.