Vassa

Three-month period of retreat for Theravāda Buddhist monks and nuns during the rainy season. It begins at the festival of Asalha in June/July, which marks the Buddha's first sermon, and ends at Assayuja in October, which commemorates the return of the Buddha from heaven after passing on his teachings to his mother. The end of Vassa is celebrated by the festival of Kathina, the robe-giving festival, in October/November.

If the rains last longer than usual the end of Vassa will occur at the festival of Kattika at the November full moon, which commemorates the departure of the first Buddhist missionaries.