Buddha Day, also known as Vesak, Visakha Puja, or Buddha Purnima, is the most sacred Buddhist holiday. It commemorates the birth, enlightenment, and death (Parinirvana) of Siddhartha Gautama, the historical Buddha. Celebrations vary across Buddhist communities, but often include reflection, meditation, and acts of kindness and generosity. 

• Significance:
  Vesak is a time for Buddhists to reflect on the Buddha's teachings and his path to enlightenment. It's a day to cultivate peace, harmony, and spread goodwill. 

• Celebrations:
  Followers may visit temples, chant sutras, offer prayers, and participate in symbolic acts like bathing a Buddha statue, which is said to cleanse bad karma. They might wear white clothing, decorate temples with lanterns, and engage in charitable acts. 

• Global Recognition:
  The United Nations officially recognized Vesak as an international public holiday in 1999, acknowledging Buddhism's contributions to spirituality. 

• Date:
  Vesak typically falls on the first full moon in May, though celebrations can vary among different Buddhist traditions.