Sri Lanka's major festival

Buddhist New Year
In Theravadas countries, 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. As for example, Chinese, Koreans and Vietnamese celebrate late January or early February according to the lunar calendar, whilst the Tibetans usually celebrate about one month later.

Vesak or Visakah Puja ("Buddha Day")
Traditionally, Buddha's Birthday is known as Vesak or Visakah Puja (Buddha's Birthday Celebrations). Vesak is the major Buddhist festival of the year as it celebrates the birth, enlightenment and death of the Buddha on the one day, the first full moon day in May, except in a leap year when the festival is held in June. This celebration is called Vesak being the name of the month in the Indian calendar.

The Elephant Festival
The Buddha used the example of a wild elephant which, when it is caught, is harnessed to a tame one to train. In the same way, he said, 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
Kandy is a beautiful city in Sri Lanka. On a small hill is a great temple which was especially built to house a relic of the 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)
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 visits 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. Many Theravadins from Cambodia, Laos and Thailand also observe this festival.
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 is a festival which celebrates 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.