Buddhist New Year Magha Puja Day (Fourfold Assembly or "Sangha Day")
In Theravadin countries like Thailand, Burma, Sri Lanka, Cambodia and Lao, the new year is celebrated for three days from the first full moon day in April. In Mahayana countries the New Year starts on the first full moon day in January. However, the Buddhist New Year depends on the country of origin or ethnic background of the people. For instance, Chinese, Koreans and Vietnamese celebrate the New Year in late January or early February according to the lunar calendar. Meanwhile Tibetans usually celebrate about one month later.
Wesak or Visakah Puja ("Buddha Day")
Wesak is the most important Buddhist festival of the year as it celebrates the birth, enlightenment and death of the Buddha, the first full moon day in May, except in a leap year when the festival is held in June. This celebration is called Wesak (Vesak) being the name of the month in the Indian calendar.
Magha Puja Day takes places on the full moon day of the third lunar month (March). This holy day is observed to commemorate an important event in the life of the Buddha. This event occurred early in the Buddha's teaching life.
After the first Rains Retreat (Vassa) at the Deer Park at Sarnath, the Buddha went to Rajagaha city where 1250 Arahats (Enlightened saints) who were the Buddha's disciples, returned from their wanderings to pay respect to the Buddha without any prior appointment. They assembled in the Veruvana Monastery with the two chief disciples of the Buddha, Sariputta and Moggalana.
The assembly is called the Fourfold Assembly because it consisted of four factors:
(1) All 1250 persons who gathered there were Arahats
(2) All of them were ordained by the Buddha himself
(3) They assembled by themselves without any prior call
(4) It was the full moon day of Magha month (March).
Asalha Puja Day ("Dhamma Day")
Asalha Puja falls on the full moon day of the 8th lunar month (approximately July. The day also commemorates Buddha's first sermon: about the turning of the wheel of the Dhamma (Dhammacakkappavattana Sutta) to the five ascetics at the Deer Park (Sarnath). Kondanna, the senior most ascetic in the group, attained the first level of enlightenment (the Sotapanna level of mind purity).
Uposatha (Observance Day)
The four monthly holy days that continue to be observed in Theravada countries - the new moon, full moon, and quarter moon days. Known in Sri Lanka as Poya Day.
This day marks the conclusion of the Rains retreat (vassa). The kathina ceremony follows in the next month, during which devotees gather to make formal offerings of robe cloth and other requisites to the Sangha.
Kathina Ceremony (Robe offering ceremony)
This ceremony is held on any convenient date within one month of the conclusion of the Vassa Retreat. It is the time of the year when new robes and other requisites may be offered to the monks.
At the end of a particular rains retreat (vassa); Buddha was so pleased with the progress of the assembled monks that he encouraged them to extend their retreat for yet another month. On the full-moon day marking the end of that fourth month of retreat, he presented his instructions on mindfulness of breathing (anapanasati), which may be found in the Anapanasati Sutta (MN 118) - The Discourse on Mindfulness of Breathing.
In Burmese tradition, this day marks the occasion when Buddha is said to have gone to the Tushita Heaven to teach his mother the Abhidhamma. It is held on the full moon of the seventh month of the Burmese lunar year starting in April that corresponds to the full moon day in October.
This is a Thai Buddhist festival that is celebrated for many days during the middle of April. During this festival, people clean their homes, wash their clothes and enjoy sprinkling perfumed water on the monks, novices and other people. They gather around the riverbank, carrying fishes in jars to put into the water. People go to the beach or riverbank with jars or buckets of water and splash each other. Boat races on the river are an important attraction of this festival.
Loy Krathong (Festival of Floating Bowls)
When the rivers and canals are full of water, the Loy Krathong Festival takes place in all parts of Thailand on the full moon night of the Twelfth Lunar month. People bring bowls made of leaves (containing flowers) along with candles and incense sticks which they float in the water. This ritual supposedly helps in getting rid of bad luck. The traditional practice of Loy Krathong was meant to pay homage to the holy footprint of the Buddha on the beach of the Narmada River in India.
The Ploughing Festival
This festival falls in May when the moon is half-full. Two white oxen pull a gold painted plough, followed by four girls dressed in white who scatter rice seeds from gold and silver baskets. This is to celebrate Buddha's first moment of enlightenment, which is said to have happened when the Buddha was seven years old, when he had gone with his father to watch ploughing in the fields. (Known in Thailand as Raek Na)
The Elephant Festival
The Buddha used to say that when a wild elephant was caught, it was always harnessed to a tame one during training. Similarly, a person new to Buddhism should have a special friendship of an older Buddhist. To mark this saying, Thais hold an elephant festival on the third Saturday in November.
The Festival of the Tooth
In Kandy, Sri Lanka, there is a famous temple, which was built to house a relic of Buddha - his tooth. The tooth can never be seen, as it is kept deep inside may caskets. But once a year in August, on the night of the full moon, there is a special procession for it.
Ulambana (Ancestor Day)
This day is celebrated throughout the Mahayana tradition from the first to the fifteenth days of the eighth lunar month. It is believed that the gates of Hell are opened on the first day and the ghosts may visit the world for fifteen days. Food offerings are made during this time to relieve the sufferings of these ghosts. On the fifteenth day, Ulambana or Ancestor Day, people visit cemeteries to make offerings to the departed ancestors. This festival is also observed in Cambodia, Laos and Thailand.
Ulambana is also a Japanese Buddhist festival known as Obon, beginning on the thirteenth of July and lasting for three days, which celebrates the reunion of family ancestors with the living.
Avalokitesvara's (Kuan Yin) Birthday
This festival is a celebration of the Bodhisattva ideal represented by Avalokitesvara, who represents the perfection of compassion in the Mahayana traditions of Tibet and China. It occurs on the full moon day in March.
Buddha Poornima or Buddha Jayanti
The most sacred festival of Buddhist is the Buddha Poornima or the Buddha Jayanti celebrated in the month of April/May. It’s an occasion to commemorate the birthday of Gautam Buddha. The significance of the day lays in the fact that it’s the same day when Lord Buddha was born, got enlightenment and attained nirvana or salvation. Buddha Poornima or the Buddha Jayanti is the auspicious occasion when the Pilgrims from all over the world come to Bodhgaya to celebrate the festival. .