Constellations are determined by the date of the solar calendar. 1July 29, 974, the Gregorian calendar date is September 15, and the constellation of that day is Virgo.
Lunar calendar: July 29th, Jiayin year.
Main branch: Does Jia have it?
Gregorian calendar:1September, 974 15 Sunday Virgo.
Source: Hua.com.