[1][2] The Buddha taught that the Uposatha day is for "the cleansing of the defiled mind," resulting in inner calm and joy.
[3] 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.
In precolonial Burma, Uposatha was a legal holiday that was observed primarily in urban areas, where secular activities like business transactions came to a halt.
During Uposatha days, Buddhist monks at each monastery assemble and recite the Patimokkha, a concise compilation of the Vinaya.
[16][17] For lay practitioners who live near a Buddhist temple, the uposatha is an opportunity for them to visit it, make offerings, listen to sermons by monks and participate in meditation sessions.
For lay practitioners unable to participate in the events of a local monastery, the uposatha is a time to intensify one's own meditation and Dhamma practice,[18] for instance, meditating an extra session or for a longer time,[19] reading or chanting special Buddhist texts,[20] recollecting[21] or giving in some special way.
"[26] The objective of the eight precepts is different from the five in that they are less moral in nature, but more focused on developing meditative concentration, and preventing distractions.
[28][27] Taiwanese physician Ming-Jun Hung and his co-authors have analyzed early and medieval Chinese Buddhist Texts and argue that the main purposes of the half-day fast is to lessen desire, improve fitness and strength, and decrease sleepiness.
[19] Describing his experience of Uposatha days in Thailand, Khantipalo (1982a) writes: Early in the morning lay people give almsfood to the bhikkhus who may be walking on almsround, invited to a layman's house, or the lay people may take the food to the monastery.
It is usual for lay people to go to the local monastery and to spend all day and night there.... [In monasteries where] there is more study, [lay people] will hear as many as three or four discourses on Dhamma delivered by senior bhikkhus and they will have books to read and perhaps classes on Abhidhamma to attend....