Visakha Bucha Day is the holiest day in the Thai Buddhist calendar. It commemorates three major events in the life of the Lord Buddha, all of which are believed to have occurred on the same full moon day of the sixth lunar month: His birth, His enlightenment (Bodhi), and His passing into nirvana (Parinirvana).

Nikini Full Moon Poya commemorates the First Buddhist Council at Rajagaha, where 500 Arahants preserved the Dhamma and Vinaya after the Buddha’s Parinibbāna. It also marks the start of the Vassana rainy retreat, strengthening monastic discipline.

Binara Full Moon Poya commemorates the establishment of the Bhikkhuni Order, when the Buddha ordained his foster mother Mahāpajāpati Gotami and 500 women. This completed the Fourfold Sangha (monks, nuns, laymen, laywomen). The event marked a historic step in recognizing women’s spiritual capacity, a legacy still honored in Sri Lanka today.

Vap Full Moon Poya commemorates the Buddha’s seventh year after Enlightenment, when he preached the Abhidhamma in Tavatimsa Heaven to his mother and later descended at Sankassapura. It also marks the end of the Rainy Retreat and the beginning of the Kathina robe-offering tradition, which continues in Sri Lanka today.