1990 What constellation was born on the first day of the fifth lunar month?

1990 is a leap year. There are two lunar months in May. If you are born on the first day of the fifth lunar month, the solar calendar is May 24th, so you are a Gemini. But if you were born on the first day of leap May, that is, June 23rd in the solar calendar, you will be born as a "cancer".