Vesak is the most important holiday in the Theravada Buddhist countries of Southeast Asia, though its observance varies from culture to culture. In the United States, it has become the occasion for a common celebration that unites different Buddhist traditions and schools, Asian and non-Asian, immigrant and convert, Theravadin and Mahayana (for different schools of Zen, which is a tradition of the Mahayana school of Buddhism, the Buddha's birthday is celebrated according to a different calendar and falls on April 8; his enlightenment and death are also assigned to different days).
Vesak celebrations are a time for the rededication of one's commitment to the Buddha's teachings and to practice. At temples all over Southeast Asia and in the West, lay devotees clean the building and festoon it with lights and lanterns. Sometimes, a special pavilion is built for monks to sit on as they meditate and chant through the night. At Metta Forest Monastery outside San Diego, a monastery in the Thai Forest tradition, lay practioners come for a candle-lit procession, to make offerings, to chant, and to sit through the night in meditation. The celebration ends the following morning with a communal meal served to the monks by dozens of laypeople. "It is a time to honor the Buddha, the dharma and the sangha, and to recommit to practice," says Thanissaro Bhikkhu, the monastery's abbot. "Something like a New Year's resolution."
No account of the Buddha's birth was recorded at the time, but Buddhist legend describes how the baby sprang miraculously from his mother's side, in what is today Nepal. Recent archeological research claims to pinpoint the exact location. In Thich Nhat Hanh's elegant telling of the life of the Buddha, "Old Path, White Clouds," he describes the birth like this:
"The king summoned all the local holy men to divine the meaning of this dream. Their conclusion: 'Your majesty, the queen will give birth to a son who will be a great leader. He is destined to become either a mighty emperor who rules throughout the four directions, or a great Teacher who will show the Way of Truth to all beings in Heaven and Earth.'
"It was the custom in those days for a woman to return to her parents' home to give birth there. Mahamaya...set out for Ramagama, the capital of Koliya. Along the way she stopped to rest in the garden of Lumbini. The forest there was filled with flowers and singing birds.Peacocks fanned their splendid tails in the morning light. Admiring an ashok tree in full bloom, the queen walked toward it, when suddenly feeling unsteady, she grabbed a branch of the ashok tree to support her. Just a moment later, still holding the branch, Queen Mahamaya gave birth to a radiant son."
The story goes that sages arrived at the scene and washed the baby in perfumed water (which is why practitioners of Zen and other Mahayana schools celebrate the birthday by pouring water over a figure of the baby Buddha). Then Mahamaya's attendants wrapped him in silk and carried him to the palace. But seven days after the birth, Mahamaya died (there is no account of how or why), and her sister, Mahapajapati, who was also married to the Buddha's father, became his surrogate mother. After the Buddha's awakening, when he began to teach, Mahapajapati became his first woman disciple and led the order of bhikshunis, or ordained nuns.