Bone-Weight Reckoning (Chengu)
Look up the Yuan Tiangang bone-weight tables by lunar year, month, day and hour; the four weights sum into a total with its classical verse — all computed on this page, your birth data never leaves the browser.
Method and pinned rules
Three pinned rules: ① the year weight follows the lunar year ganzhi (switching at lunar New Year); ② a leap lunar month takes the base month's weight; ③ the late Zi hour (23:00-24:00) counts as the next day. Tables and verses follow the public-domain Yuan Tiangang Chengu Ge (archived and verified in this site's annex).
Source: the public-domain Yuan Tiangang Chengu Ge (attributed, Tang dynasty).