yuanzi-basic-bazi

Calculate a deterministic, privacy-minimized basic Four Pillars (Bazi) chart from solar or lunar birth date, local time, IANA time zone, optional longitude, true-solar-time choice, and day-boundary convention. Use when a user asks to calculate, verify, compare, or explain the factual structure of a basic Bazi chart. Do not use it to invent readings, luck cycles, compatibility, shensha, or predictions.