Constellations are determined by the date of the solar calendar. The Gregorian calendar date of June 1956 is July 20th, and the constellation of that day is Cancer.
Lunar calendar: June 13th, Bingshen.
Main branch: Ziguihai, Wei Wu, Bing Shen Yi.
Gregorian calendar:1Friday, July 20th, 956 Cancer.
Source: Hua.com.