This day marks the end of the rainy season in Asian countries as well as in Bangladesh, where Theravada Buddhism is practiced. Barsha Brata (Vassa / Rains Retreat) starts at Ashari Purnima and ends at Pavarana Purnima. On This day, each monk (Pali: Bhikkhu) must come before the community of monks ( Sangha ) and atone for the offense he may have committed during the Barsha Brata.

In India, where Buddhism began, there is a three-month-long rainy season. According to the Vinaya (Mahavagga, Fourth Khandhaka, section I), in the time of the Buddha, once during this rainy season, a group of normally wandering monks sought shelter by co-habitating in a residence. In order to minimize potential inter-personal strife while co-habitating, the monks agreed to remain silent for the entire three months and agreed upon a non-verbal means for sharing alms.

After this rains retreat, when the Buddha learned of the monks' silence, he described such a measure as "foolish." Instead, the Buddha instituted the Pavarana Ceremony as a means for dealing with potential conflict and breaches of disciplinary rules (Patimokkha) during the vassa season.

The Buddha said: 'I prescribe, O Bhikkhus, that the Bhikkhus, when they have finished their Vassa residence, hold Pavâranâ with each other in these three ways: by what [offence] has been seen, or by what has been heard, or by what is suspected. Hence it will result that you live in accord with each other that you atone for the offences (you have committed), and that you keep the rules of discipline before your eyes.'

During this Barsha Brata (Vassa / Rains Retreat) for Monastic, these are often days of more intensive reflection and meditation along with their "Ten Precepts". In many monasteries physical labor (construction projects, repairs etc) is curtailed.

Lay people observe the "Eight Precepts" on Uposatha days, as a support for meditation practice and as a way to re-energize commitment to the Dhamma. Whenever possible, lay people use these days as an opportunity to visit the local monastery in order to make special offerings to the Sangha( Monks).

This whole program come to the conclusion after Kathina Ceremony (Robe offering ceremony)which is held on any convenient date within one month of the conclusion of the Vassa Retreat, which is the three month rains retreat season (Vassa) for the monastic order. It is the time of the year when new robes and other requisites may be offered by the laity to the monks.