FOUR MAJOR FESTIVALS
There are four major Special Buddha days or “Festivals” (düchen) in a year which relate to the life of Buddha Shakyamuni. During these days, it is said that the effects of positive or negative actions are multiplied 100 million times, so practice is strongly advised.
During the first two weeks of the new year, it is celebrated that the Buddha displayed a miracle each day to increase the merit and devotion of future disciples. During these days, the Gelugpa Mönlam Chenmo (great prayer festival) is celebrated and extra practice is highly advised. The 15th of the 1st month is the “Day of Miracles”.
Saga Dawa Düchen:
The 15th of the 4th month, Buddha Shakyamuni’s Birth, Enlightenment and Parinirvanaare celebrated. He was born in Lumbini (current-day Nepal) became enlightened in Bodhgaya (India) and entered parinirvana (“passed away”) in Kushinagar (India).
The 4th of the 6th month, the “First Turning of the Wheel of Dharma” (first teaching) is celebrated. For the first seven weeks after his Enlightenment, Buddha did not teach. Encouraged by Indra and Brahma, he then gave his first teachings at Sarnath on the Four Noble Truths.
Lha Bab Düchen:
The 22nd of the 9th month, ‘Buddha Shakyamuni’s Descent from the Heaven of 33’ is celebrated. Buddha’s mother had been reborn in Indra’s heaven. To repay her kindness and to benefit the gods, Buddha spent three months teaching in the Heaven of 33. This is not as often stated, in Tushita heaven; Tushita is the realm where the Buddha lived before he descended to Earth. Possibly somewhat confusing can be that one week before, on the 15th of the 9th month, it is celebrated that he accepted to return from the Heaven of 33.
In the Theravada tradition the following main full-moon days are observed (information from Urban Dharma):
Magha Puja (‘Sangha Day’)
The Buddha gave the teaching on the basis of the discipline (Ovada Patimokkha) to the spontaneous gathering of 1250 arahants.
Vesakha Puja (Wesak) (‘Buddha Day’)
The birth, enlightenment and passing away of the Buddha.
Asalha Puja (‘Dhamma Day’)
The Buddha’s first discourse, given to the five samanas in the Deer Park at Sarnath, near Varanasi. The traditional Rainy-Season Retreat (Vassa) begins on the next day.
This marks the end of the three-month Vassa-retreat. In the following month, lay people may offer the Kathina-robe as part of a general alms-giving ceremony.
For an extensive list and explanation of Buddhist festivals, see the Buddhanet website.