Nikini Full Moon Poya Day, the second Poya in the Vas season (Rainy-retreat) is observed today.
Attainment of Arahatship by the Buddha’s chief attendant, Ananda Maha Thera, commencement of the first Dhamma Sangayana, convocation to settle the Buddhist canon and “Pasu Vas” or the commencement of the “Vas” period by those who had not started the period of sojourn on the Esala full moon day are some of them. For Sri Lankans this day is also significant because the world famous Kandy Esala Perahera ends on this day.
The “Pali” word “Vas” means the rains “Viseema” means dwelling. Therefore “Vas Viseema” in Sinhalese means to sojourn during the rainy season. “Vassana Kala” or the rainy season of three months begins on Esala full moon day. Commencing the “Vas” period from Esala full moon day is called “Purmikawa” or “Pera Vas”. However the bhikkhus who could not commence the Vas period on Esala Full Moon day are allowed to start observing Vas on the Nikini Full Moon day. This is called “Pasuvas”.
Nikini Poya day celebrates the first ever Dhammasangayana – The First Buddhist Council where, what the Buddha said, was agreed upon and recited. This took place at the Sattapanni Rock Cave in Rajagaha , under the patronage of Mahakassapa Thera and it went on for seven long months. It established the original authentic Tipitaka: The 3 Baskets of Sacred Text = The Pali Canon spoken by the historical Buddha and his disciples.