Zassetsu (八十八夜・二百十日) (雜節)

THE JAPANESE 雑節 (zassetsu) — the farmer's own markers beside the 24 solar terms, each a working instruction: 八十八夜, the eighty-eighth night from Risshun, when the new tea is picked and the last frost says goodbye (the song every Japanese child knows: 夏も近づく八十八夜); 二百十日 and 二百二十日, the typhoon danger days around which Toyama dances the Kaze-no-Bon to still the wind; 入梅, the calendrical opening of the rains at solar longitude 80°; 半夏生 at 100°, the rice-planting deadline — and in Kansai the day to eat octopus, that the roots may grip like tentacles. EVERYTHING COMPUTED FROM THE SKY AND GAZETTE-LOCKED: Risshun and the longitude markers from the shared ephemeris resolved to the JST civil day (the catalogue's hard-won 節切り discipline), the day-counts by pure offset — and ALL FIVE 2026 cells of the National Astronomical Observatory's own 暦要項 (Risshun 4 Feb, 八十八夜 2 May, 入梅 11 Jun, 半夏生 2 Jul, 二百十日 1 Sep) reproduced at load or boot fails. THE HONESTY RAIL: the calendrical 入梅 is NOT the JMA's observational rainy-season declaration — never blended. 節分, 彼岸, 土用 and 社日 already live in their own engines. Japanese becomes twenty-three. Pure compute, no LLM.

Cost: 1 TIAN Points per call. tRPC procedure zassetsu.year.