Constellations are determined by the date of the solar calendar. 1965 Lunar April 10 solar calendar date is 10 May, and the constellation of that day is Taurus.
Lunar calendar:1April 965 14.
Main branch: Yi Si Xin Si Jia Ji Zi Si
Gregorian calendar:1May 965 10 Monday Taurus
Source: Hua.com.