Buddhist Lent Day is a period of three lunar months during the rainy season when monks are required to remain in one particular place or wat (temple). Khao Phansa Day is on the first day after the full moon of the eighth lunar month (this year is on July 14th,2003) and marks the beginning of the three-month Buddhist 'lent' period. The tradition of Buddhist Lent or the annual three-month rains retreat known in Thai as "Phansa". Khao Phansa means to remain in one place during the rainy season. Phansa represents a time of renewed spiritual vigor and Khao Phansa festival is a major Buddhism merit-making festival.
There is an ancient tradition that the monks repeat three times saying “I stay in this monastery for three months” this is the Buddhist lent as proclaimed by the Buddha.