Vesak is considered a religious as well as a cultural festival in Sri Lanka.
Buddhists commemorate the important events that took place in the life of Lord Buddha on this Vesak Full Moon Poya Day. First comes the birth of Siddhartha Gautama in Lumbini in Nepal which took place under the arbor of Sat trees where queen Mahamaya gave birth to him. The second event was Siddharta Gautama's supreme attainment as the Buddha, the Enlightened One. The third event was Lord Buddha's Parinibbana over 2500 years ago at Kusinagar.
Nawam Poya Day is Today
Navam full moon has special significance for the Buddhists in Sri Lanka and in the world. The two very significant incidents that took place on the Navam Pura Pasalosvaka Poya Day were the first ever Buddhist congregation and the appointment of two chief disciples of Gautama Buddha as Aggasavakes namely Sariputta and Moggallana. In the eve of the first Navam Full Moon Poya day after the Enlightenment of Gauthama Buddha, there were more than One thousand two hundred and fifty disciples in the Order of Maha Sangha.
Unduvap Poya is the last Full Moon Poya day of the year and commemorates the arrival of Sangamitta Theri in Sri Lanka with a Bo sapling from the sacred Jaya Sri Maha Bodhi in India during the month of Unduwap.
Il Full Moon Poya Day is the last Poya in the rainy season. On Il Full Moon Poya Day was the receipt of permission (Niyatha Vivarana) by Bodhisatra Maitriya to be the next Enlightened One or the Future Buddha Maitriya. Siriwaddana had entered the Buddhist Order as Bhikku Maitriya. The Buddhas with his divine vision and insight predicted that in Benares there will be a kingdom known as “Kethumathi” and a king called Sanka whose advisor Subrahamme and his wife Brahamawathi will be parents of Future Buddha Maitriya and that he will attain enlightenment under Banyan Tree.
Binara Pasalosvaka Poya occupies a significant place in the history of Buddha Sasana. It is on this Poya day, Bhikkhuni Sasana was founded.
The Vinaya Pitaka and Anguttara Nikaya give the following account on setting up the monastic order for women thus: At one time the Buddha was in Kapilavatthu and his step-mother, Maha-Pajapati Gotami asked permission to go forth into the homeless life.