Khao Phansa Day is a Buddhist holiday observed in Thailand on the first day following the full moon occurring in the eighth month of the Thai lunar calendar.

​

Khao Phansa marks the first day of “Buddhist Lent,” a time when observant Buddhists fast from such things as meat, alcohol, and tobacco. For the most part, only Theravada, rather than Mahayana, Buddhists observe Khao Phansa, and even many Theravada practitioners choose not to fast.

​

Another name for Khao Phansa is “the Rains Retreat” because it occurs at the beginning of Thai rainy season and because Buddhist monks take this opportunity to retreat inside their temples for a three-month period of study and meditation. This tradition of a “rainy season retreat” predates Buddhism, but it was followed by Buddha during his lifetime, which encourages many to emulate him today.

​

Many monks enter monastic life on Khao Phansa Day, staying in monasteries and temples until the rainy season ends on Wan Ok Phansa Day. The number of rainy seasons, called “Vassas,” spent in isolation is the measure used to count how many years a Thai Buddhist monk “has been a monk.” After Vassa, Thai Buddhists celebrate the festival of “Kathina,” during which the people bring donations to local temples, which often consist of new robes given to the monks.