Boun Khao Phansa marks the beginning of Buddhist Lent, which lasts from July until October.
It is the traditional three month "rains retreat" during which Buddhist monks are expected to stay in their own temple to study the Buddha’s teaching as well as meditating. They are not allowed to travel anywhere or revert to being laymen. Early the morning of Boun Khao Phansa people prepare donations of food (particularly khaotom, rice, banana or pork wrapped in banana leaves) and necessities like soap, toothpaste and toothbrushes and towels for the monks. Most temples are very busy during this time. Lent ends on the full moon in October the Kathin ceremony when monks receive gifts.