Uposatha

The Uposatha (Sanskrit: Upavasatha) is Buddhist day of observance, in existence from the Buddha's time (500 BCE), and still being kept today in Buddhist countries. The Buddha taught that the Uposatha day is for "the cleansing of the defiled mind," resulting in inner calm and joy. On this day, both lay and ordained members of the sangha intensify their practice, deepen their knowledge and express communal commitment through millennia-old acts of lay-monastic reciprocity. On these days, the lay followers make a conscious effort to keep the Five Precepts or (as the tradition suggests) the Eight Precepts. It is a day for practicing the Buddha's teachings and meditation.

Observance days

Depending on the culture and time period, uposatha days have been observed from two to six days each lunar month.

Theravada countries

In general, Uposatha is observed about once a week in Theravadin countries in accordance with the four lunar phases: the new moon, the full moon, and the two quarter moons in between. In some communities, such as in Sri Lanka, only the new moon and full moon are observed as uposatha days.