Poya Days (Sri Lanka) (斯里蘭卡滿月節)

SRI LANKAN POYA DAYS — the full-moon uposatha holidays that structure the island's Buddhist year, Duruthu through Unduvap, every one a public holiday: Vesak (the Buddha's birth, enlightenment and parinibbāna), Poson (Arahat Mahinda brings Buddhism to Lanka), Esala (the first sermon and the Kandy perahera season). THE LOOP'S ROUND-55 DEFERRAL, CLOSED THE GAZETTE WAY: the official dates follow the state almanac's Surya-Siddhanta-lineage computation and CANNOT be reproduced from modern astronomy — Poson 2025 was gazetted June 10 against a June 11 astronomical full moon — so this engine serves the PUBLISHED tables only (2024–2027, two independent witnesses per year, arbitrations recorded: the 2027 Gazette Extraordinary No. 2493/05 overrules a prediction site's Medin/Vesak by one day; 2024's Navam settled 2–1 against the astronomical date) and REFUSES unpublished years by name (2028: single-sourced). Load-time laws: canonical name sequence, lunation-sized gaps, every date within 1.5 days of a true astronomical full moon. 2026 is the thirteen-poya year with Adhi Poson (May 30) flagged. Any date returns whether it is a poya (name, significance), the next poya with countdown, and the year's full table. Sri Lanka's Sinhala Buddhist reckoning becomes the catalogue's 35th tradition. Pure compute, no LLM.

Cost: 2 TIAN Points per call. tRPC procedure poya.check.