Constellations are determined by the date of the solar calendar. The Gregorian calendar date of 8 1977 is September 26th, and the constellation of that day is Libra.
Lunar calendar:1August 977 14.
Main branches: Ding Si, Ji You and Bing Xu.
Gregorian calendar:1Monday, September 26th, 977 Libra
Source: Hua.com.