Vesākha (Pali; Sanskrit: Vaiśākha), also known as Buddha Purnima and Buddha Day, is a holiday observed traditionally by Buddhists on different days in India, Sri Lanka, Nepal, Tibet, Bangladesh, Bhutan, Indonesia, Philippines, Singapore, Vietnam, Thailand, Cambodia, Laos, Malaysia and Myanmar and in other places all over the world. Sometimes informally called "Buddha's Birthday", it actually commemorates the birth, enlightenment (nirvāna), and death (Parinirvāna) of Gautama Buddha in the Theravada or southern tradition.
The decision to agree to celebrate Vesākha as the Buddha’s birthday was formalized at the first conference of the World Fellowship of Buddhists held in Sri Lanka in 1950, although festivals at this time in the Buddhist world are a centuries-old tradition. The resolution that was adopted at the World Conference reads as follows:
On Vesākha Day, Buddhists all over the world commemorate events of significance to Buddhists of all traditions: The birth, enlightenment and the passing away of Gautama Buddha. As Buddhism spread from India it was assimilated into many foreign cultures, and consequently Vesākha is celebrated in many different ways all over the world. In India, Vaishakh Purnima day is also known as Buddha Jayanti day and has been traditionally accepted as Buddha's birth day.