Lunar calendar
Kathina is a Buddhist festival which comes at the end of Vassa, the three-month rainy season retreat for Theravada Buddhists in Bangladesh (known as Kaṭhina Cībar Dān), Cambodia, Laos, Malaysia, Myanmar, Sri Lanka, India and Thailand. The season during which a monastery may hold Kathina is one month long, beginning after the full moon of the eleventh month in the Lunar calendar (usually October).