Definition
Visakha Puja, or the Day of Vesak, is the festival celebrating the birth, enlightenment and parinirvana (passing away) of the Lord Buddha. It falls on the full moon day of the month of Visakha or Vesak, the sixth lunar month, (which usually falls during the period May in the Gregorian calendar).Significance
According to the Theravada tradition, the three most important events in the life of the
Buddha-his birth, his entry into enlightenment and his achievement of
parinirvana-all occurred on the full moon day of Visakha. Aspects of the
Dharma relating to the birth, enlightenment and parinirvana of the Buddha
include gratitude, the Four Noble Truths and mindfulness.