Constellations are determined by the date of the solar calendar. 1989 The Gregorian calendar date of the fifteenth day of the first lunar month is February 20th, and the constellation of that day is Pisces.
Lunar calendar: 15th day of the first month in year of the snake.
Ganzhi: I have been in Bingyin Xinhai.
Gregorian calendar:1Monday, February 20th, 989 Pisces.
Source: Hua Wang.