Ship's Bells & Watches (船鐘更制)

SHIP'S BELLS AND THE WATCH SYSTEM — the sea's own clock: for four centuries the sailing world told time by bells struck each half hour of a four-hour watch, one to eight; 'eight bells' has meant the watch's end — and in the sailor's obituary, the end of the last watch. THE DOG-WATCH THEOREM is the jewel, asserted at load: six four-hour watches divide the day EVENLY, and that evenness is the problem — a two-section crew would keep the same hours forever, the same men on the graveyard middle watch every night — so the 16:00–20:00 watch was SPLIT into two dog watches, making SEVEN a day, and seven is ODD: the sections rotate automatically, every day, by parity alone (and both watches get supper). Scheduling theory, three centuries early. THE MUTINY LEGEND served as lore: the British Last Dog Watch strikes 1, 2, 3 — then EIGHT, with five, six and seven proven never struck (the Nore mutiny story labeled the navy's own legend). The pairs-then-single strike pattern rendered; sixteen bells at New Year's midnight carried. Western becomes fifty-two. Pure compute, no LLM.

Cost: 1 TIAN Points per call. tRPC procedure shipsBells.time.