Uposatha is the day of the rest in Buddhism. This day was formulated by Buddha on request of King Bimbisara. According to Gautama Buddha on this day the polluted minds will be purified and this would lead to the tranquility and happiness of mind. He asked the monks to teach the lay followers and recite Patimokkha during Uposatha Day.

Uposatha in Sanskrit literally means `upavastha.` It refers to the pre-Buddhist fast day that gives way to the Vedic sacrifices. Depending on the four phases of moon the weekly Uposatha is held. In few Buddhist communities the Uposatha is observed only on the full moon and new moon days.

According to traditional Buddhism there are five important Uposatha days. These are:-

Vesak or Buddha Day: This single day marks the three most important stages of Buddha`s life---His birth, enlightenment and Parinirvana.

Asalha Puja or Dhamma Day: This day celebrates the first preaching of Buddha. It is also significant as the process of ordination started from this day.

Pavarana Day: On this day the rain retreat comes to an end.

Magha Puja: One of the foremost festivals of Buddhism, it marks the assembling of 1250 arahants to meet Buddha.

Anapanasati Day: As the Rain Retreats came to an end Buddha was quite pleased with the progress of the monks. He asked them to stay for another month. At the end of the fourth month he delivered the sermon on the mindfulness of breathing.

Another ceremony that is part of the uposatha day is the Observance Practice. This day is meant for a lay follower who is required to observe the Eight Precepts. On this day they have to reaffirm their faith and belief in Buddha and his marga. The Buddhist followers visit a nearby monastery and hand over their offerings to the Sangha. Talks on Dhamma, chanting of Suttas and practice of meditation takes place on this day.

As far as the Sangha is concerned the practices differ for them. The monks are expected to undertake meditation and intensive reflection; recite Bhikku Patimokkha on full and new moon days and the recitation is preceded by confessions.