Pāli equivalent of the Sanskrit term poṣadha.indicating the day preceding the four stages of the moon's waxing, that is the 1st, 8th, 15th, and 23rd nights of the lunar month. Long before the advent of Buddhism these were considered sacred days in India. In particular, these days were utilized by the pre-Buddhist reforming communities for the expounding of their views, a practice that early Buddhists adopted. Buddhists also utilize one or other of these uposatha days for the recitation of the Prātimokṣa.the set of monastic rules which are contained in the Sūtra Vibhaṇga of the Vinaya Piṭaka. On uposatha days laymen take upon themselves the Eight Precepts (aṣṭāṇga-śīla), known on that occasion as uposatha vows.