Discordian Calendar (ddate) (混沌曆)

THE DISCORDIAN CALENDAR — the calendar of the Principia Discordia (1963–65), carried into every Linux distribution for decades by the classic ddate program: five seasons of 73 days (Chaos, Discord, Confusion, Bureaucracy, The Aftermath), a five-day week (Sweetmorn through Setting Orange), years counted from 1166 BC (2026 = YOLD 3192), and ST. TIB'S DAY intercalated on 29 February, standing outside both season and week. THE THEOREM THAT MAKES IT TICK, ASSERTED AT LOAD: 5×73 = 365 ≡ 0 (mod 5), so the calendar is PERENNIAL — every date keeps the same season, day and weekday in every year, forever; 1 January is always Sweetmorn, Chaos 1. ALL TEN HOLYDAYS (the Apostle 5ths: Mungday, Mojoday, Syaday, Zaraday, Maladay; the Flux 50ths: Chaoflux through Afflux) are DERIVED from the season arithmetic and required at load to land on their published Gregorian dates — ten derivations, zero disagreement — and the intercalation law (St. Tib's exists exactly when 29 February does) is asserted both ways. SERVED WITH ITS OWN FRAME: a parody religion's real calendar, computed faithfully — the theology is a joke that knows it, the arithmetic is entirely serious, and the ddate string comes back exactly as the program every hacker has typed once would print it. Pure compute, no LLM, no prophecy: fnord.

Cost: 1 TIAN Points per call. tRPC procedure discordian.day.