Wesak Celebration (ウェーサーカ祭)
Wesak is a Buddhist celebration conducted once a year. (Cambodia:Visaka Bochea,India, Bangladesh, Nepal: Visakah Puja, Buddha Purnima or Buddha Jayanti,Thailand: Visakha Bucha,Vietnam:Phật Đản,Indonesia:Waisak,Sri Lanka and Malaysia:Vesak (Wesak),Chinese language areas:fó dàn,Tibet:Saga Dawa,Laos:Vixakha Bouxa)
Wesak is celebrated in Southeast Asia as well as in Hong Kong and Taiwan, but in East Asia where Mahayana Buddhism (Northern Buddhism) had spread, the birth of Buddha (called Kanbutsue, Buttan, Gotane, Busshoe, Yokubutsue, Ryugee or Birthday of Buddha) is celebrated in its place.
According to Mahayana Buddhism, Wesak celebration is the equivalent of Vaisakha in Sanskrit (same as Vaisakha, the second month in the Indian calendar). It is called Ka-sone-la-pyae in Myanmar, meaning the festival of full moon, and is celebrated in February of the Myanmar calendar.
The date of Wesak celebration depends on the region and the calendar adopted by different sects of Buddhism. In Theravada Buddhism, which uses a calendar based on the year of Buddha's death, Wesak is celebrated on the day of Uposatha (usually in May or June of their calendar) when there is a full moon. It is celebrated on the day of the first full moon in April of the Chinese calendar in China. The celebration falls on different dates of the Gregorian calendar but is usually held some time in April or May.
Wesak is unofficially called the celebration of the birth of Buddha because it is part of the three greatest celebrations in Buddhism along with Enlightenment and Nirvana. (In Japanese Buddhism, the birth, the enlightenment, and death of Buddha are celebrated on different dates, but Southern Buddhism teaches that they all occurred on the same day of the same month.)