Constellations are determined by the date of the solar calendar. 1990 The Gregorian calendar date of the 22nd day of the twelfth lunar month is 199 1 February 6th, and the constellation of that day is Aquarius.
Lunar calendar: 199 1 22nd of the twelfth lunar month.
Main branch: Wei Xin Geng Yin Ding Wei.
Gregorian calendar: 199 1 Wednesday February 6th, Aquarius.
Source: Hua.com.