Since Sri Lanka is predominantly Buddhist country, Buddhist festivals are more frequent. In fact, full moon day of every month is regarded as a religious observance for the Buddhists; it is called Poya Day. However, the main full moon days reminiscent to the religious important events are :-
Duruthu Perahera :-
Held on the poya day in January at the Kelanyia Raja Maha Vihara in Colombo and second in importance only to the huge Kandy perahera, this festival celebrates a visit by the Buddha to Sri Lanka.
This full moon day is a day of the great significant for the Buddhists around the world for it marks the Birth, Enlightenment, and Decease of the Buddha. The Buddhist houses on the island are decorated with bright Vesak lanterns. The alms halls offer free meals to passer-by and Buddhists go to temples or shrines for religious observance.
Poson Poya :-
The Poson full-moon day in june is a celebration of the bringing of Buddhism to Sri Lanka by Mahinda. Anuradhapura and Mihintale, where Mahinda met and converted the Sinhlse king, are the main sites for the elebration. On this day thousands of white-clad piligrims climb the stairs to the summit of Mihintale.
Kandy Esala Perahera :-
The Kandu Esala Perahera, the most important and spectaular festival in Sri Lanka, is the Climax of 10 days and nights during the month of Esala, ending on the Nikini full moon. This great procession honours the scared Tooth Relic of Kandy. Smaller peraheras are held at other locations around the island.
This festival is held in Jaffna and Colombo. The gilded chariot of Skanda(or Murugan), the God of war, complete with this vel (trident), is ceremonially hauled from a temple has a 25-day festival in honour of Skanda/Murugan.
Thai Pongal :-
This is a Hindu harvest festival, held in mid-january, to honour the Sun God.
Maha Shivrathri :-
In late february or early March the Hindhu festival of Maha Sivarathri commemorates the marriage of Shiva to Parvati.
This festival is held at Kataragama, where devotes put themselves through the whole gamut f ritual masochism. Apilgrimage from Jaffna via Batticaloa to Kataragama takes place.
Also known as the festival of lights, Deepavali festival takes place in late October or early November. Thousand of oil lamps will be lit to celebrate the victory of good over evil and the return of Rama (the legendary character of the Hindu epic Ramayana, believed to be an incarnation of Vishnu) after his period of exile. Lakshmi, the goddess of wealth is worshipped on the third day of the festival.
The Christain Good friday holiday usually falls in late March. An Easter passion play is performed on the island of Duwa, off Negombo.
Muslim Festivals :-
Muslim community is quite isolated from other ethnic group, their celebration are not then displayed to public. Most of Muslim festivals are also closely connected to religion. The main Muslim festivals are the Milad-un-Nabi or the birth of the Prophet Mohammed in December, Id-ul-Fitr marking the end of the holy fasting during the month of Ramadan, and the Haj festival when Muslims make their pilgrimages to the holy Muslim shrine in Mecca.