Kathina is a Buddhist festival which comes at the end of Vassa, the three-month rainy season retreat for Theravada Buddhists. 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). It is a time of giving, for the laity to express gratitude to Buddhist monks and nuns.Lay Buddhists bring donations to temples, especially new robes for the monks. Click here to read article from wikipedia.com