This day marks the start of the Buddhist Lent.
It comes the day after Asanha Bucha Day, and will last for three lunar months, ending on Awk Pansa Day
During this time monks are confined to the temple grounds, a practice that was originally intended to keep holy men from travelling during the raining season and trampling crops.
Some Buddhists will use this time to reaffirm their spiritualness, by giving up certain pleasures such as alcohol or smoking.