Sri Lankan Buddhism · full moon · monthly observance
What are Sri Lankan Full Moon Poya Days?
Poya is the Sinhala name used in Sri Lanka for a Buddhist observance day. Each full moon has its own Poya name and place in Sri Lankan Theravāda Buddhist life.
A monthly rhythm of practice
Poya days create regular time for Buddhist observance.
Participation varies. People may visit a temple, observe sīla (ethical precepts), meditate, listen to Dhamma teachings, offer alms, or devote more time to reflection and compassionate conduct.
Important annual commemorations also fall within this cycle. Vesak remembers the Buddha’s birth, awakening, and parinibbāna. Poson remembers the Dhamma mission of Arahant Mahinda and the establishment of the Buddha Sāsana in Sri Lanka.
The annual cycle
Sri Lanka’s calendar gives each full-moon observance a Poya name.
The regular sequence is Duruthu, Navam, Medin, Bak, Vesak, Poson, Esala, Nikini, Binara, Vap, Il, and Unduvap. A year may include an additional Adhi Poya name.
How the date is assigned
Sri Lanka’s annual government order supplies the official dates.
Under Sri Lanka’s Holidays Act, the responsible minister declares the Full Moon Poya Days for each year. Open Pañcāṅga uses those official dates separately from its Hindu pūrṇimā calculation. Poya is Sinhala; pūrṇimā is Sanskrit. The words belong to different calendar traditions even when both have a full-moon connection.
The Sky Explorer identifies a named Poya Day from a maintained annual Sri Lankan government calendar. An expired year prompts a fresh reviewed source instead of preserving old dates or guessing a replacement.
References: Sri Lanka Holidays Act · Central Bank of Sri Lanka, current bank holidays · Sri Lanka government, Poson observance