Constellations are determined by the date of the solar calendar. The Gregorian calendar date of August 1985 in the lunar calendar is September 28th, and the constellation of that day is Libra.
Lunar calendar: August 14th, the Year of the Ugly Ox.
Gregorian calendar:1Saturday, September 28th, 985 Libra
Ganzhi: one ugly and one excellent Geng Wu
Source: Hua.com.