The constellation is determined by the date of the solar calendar. The date of the eighth day of September 4 in the Gregorian calendar is May 2, and the constellation of that day is Taurus.
Lunar calendar: the eighth day of April in Gengwu.
Branches: Geng Wu, Chen Geng and Ding Mao.
Gregorian calendar:1Wednesday, May 2, 990 Taurus
Source: Hua.com.