Constellations are determined by the date of the solar calendar. 1The Gregorian calendar date on August 29th, 976 is1September 22nd, 976, and the constellation of that day is Libra.
Lunar calendar: August 29th in the year of Chen Bing.
Branches: Chen Bing, Ding You, Ding Chou
Gregorian calendar:1Wednesday, September 22, 976 Libra.
Source: Hua.com.