The Uposatha (Sanskrit: Upavasatha) is a Buddhist day of observance that dates back to the Buddha’s time (600 BCE) and is still observed by Buddhist practitioners today. According to the Buddha, the Uposatha day is for “the purification of the contaminated mind,” which results in inner peace and joy.
On this day, both lay and consecrated sangha members develop their practise, broaden their understanding, and express communal devotion through millennia-old acts of lay-monastic reciprocity.
On these days, lay followers make a conscious effort to follow the Five Precepts or (as tradition does) the Ten Precepts. It is a day for meditating and practising the Buddha’s teachings.
Uposatha days have been observed from two to six days each lunar month, depending on culture and time period.
In general, Uposatha is observed once a week in Theravada countries in accordance with the four lunar phases: the new moon, the full moon, and the two quarter moons in between.
In certain countries, such as Sri Lanka, only the new and full moons are observed as uposatha days.
The uposatha is an occasion for lay practitioners who live near a Buddhist temple to visit there, give contributions, listen to monk preaching, and engage in meditation sessions.
For lay practitioners who are unable to attend a local monastery’s events, the uposatha is a time to deepen one’s own meditation and Dhamma practice, such as meditating an extra session or for a longer period of time reading or chanting special Buddhist texts, recollecting or giving in some special way.
The eight precepts are designed to give ordinary people an idea of what it is like to live as a monk, and they “may function as the thin end of a wedge in attracting some to monastic life.” The eight precepts differ from the five in that they are less moral in character and are more focused on building meditative concentration and avoiding distractions.
The third precept of the eight is about maintaining purity. As a result, Buddhist tradition expects ordinary people to be pure on observance days, which is similar to the historical Indian habit of being pure on parvan days. The sixth rule states that no food should be consumed after midday, in imitation of a nearly identical rule for monks.
The seventh guideline is frequently interpreted as not wearing colourful clothes, which has led to a practise of wearing simple white when observing the eight precepts. This does not always imply that a Buddhist devotee clothed in white is always adhering to the eight precepts.
The eighth precept, avoiding sitting or sleeping on luxurious seats or beds, usually equates to sleeping on a floor mat.
Khmer monks practise Theravada Buddhism. They respect the rule (Vinaya) as handed down by the Buddha, which defines a monk’s status as a mendicant and serves as a source of contemplation on what things are truly necessary.
However, during colonial administration, Sunday has replaced Uposatha as the legal day of rest.