Obon (お盆; [o.boꜜɴ]) or just Bon (盆; [boꜜɴ]) is a fusion of the ancient Japanese belief in ancestral spirits and a Japanese Buddhist custom to honor the spirits of one's ancestors. This syncretic folk Buddhist custom has evolved into a family reunion holiday during which people return to ancestral family places and visit and clean their ancestors' graves when the spirits of ancestors are supposed to revisit the household altars. It has been celebrated in Japan for more than 500 years and traditionally includes a dance, known as Bon Odori.
The festival of Obon lasts for three days; however, its starting date varies within different regions of Japan. When the lunar calendar was changed to the Gregorian calendar at the beginning of the Meiji era, the localities in Japan responded differently, which resulted in three different times of Obon. Traditionally, Obon was celebrated on the 15th day of the seventh month of the lunar calendar.
