(1) Observance day which occurs on a dark or full moon day, (2) Observance — either the recitation of the Patimokkha, the declaration of purity, or determination of the day — that the bhikkhus and bhikkhunis perform on this day.
Observance day, the day of the new and of the full moon; traditionally, in India, a time of special spiritual practices. The Buddha adopted this as the day for reciting the Patimokkha.
uposatha]: Observance day, corresponding to the phases of the moon, on which Buddhist lay people gather to listen to the Dhamma and to observe special precepts. On the new-moon and full-moon uposatha days monks assemble to recite the Patimokkha rules. [ MORE