Constellations are determined by the date of the solar calendar. 1990 The Gregorian calendar date of May after the lunar calendar 17 is July 9, and the constellation of that day is Cancer.
On May 17th of the lunar calendar, Geng Wu.
Main branch: Gengwu Guiwei Yihai
Gregorian calendar:1Monday, July 9, 990 Cancer
Source: Hua.com.