Thai rituals can be classified in many ways. There are ecclesiastical rituals often guided by texts called kammavaca which are part of the daily and yearly schedule of monks. These calendrical rituals include daily morning and evening prayers ( tham wat chao , tham wat yen ), mutual confession ( fortnightly meetings of the Buddhist monastic assembly, at the times of the full moon and the new moon, to reaffirm the rules of discipline). The uposatha observance, is held every two weeks, and the Pa ṭ imokhha (the monastic code) is chanted in full. Often monks are judged as "trained" in Thai Buddhism when they can chant the whole text from memory. For many is this is a de facto examination that is expected of any monk who has been in the robes more than two or three years, if not sooner. Some monasteries are famous for having monks who can chant the Patimokkha very quickly and others whose monks can chant it very beautifully.Besides these bi-weekly ceremonies. South and Southeast Asian Buddhists (although it only became a custom later) added the quarter days in the lunar cycle to the list of monthly days of observance, establishing four Sabbath-like days each month (known as wan phra in Thailand). Uposatha days are times in which devout (or even casually observant) lay Buddhists often voluntarily vow to keep eight precepts (i.e.: refraining from: *consuming intoxicants; *abusing others with speech, untruths, slander, rumors)
Besides these monastic rituals, monks also oversee and perform (chanting, blessing water, accepting gifts, giving sermons) numerous annual celebrations marking important events in the life of the Buddha. These include: