The birthday of the Prince Siddhartha Gautama is a holiday traditionally celebrated in Mahayana Buddhism on the day of the full moon in May.

Japan, which uses the Gregorian calendar, celebrates the birthday annually on April 8, or the 8th day of the fourth month. The Japanese celebration is referred to as hanamatsuri, or “flower festival,” occurring when the sakura (cherry blossom trees) bloom.

In Nepal, celebrations of Buddha's birthday occur on the full moon day of May. In India, the birth date is observed as Buddha Purnima celebrating his birth, enlightenment, and death on the full moon day of the month Vaisakha.

Buddha's Birthday is an official public holiday in Hong Kong, Macau, and South Korea.