1990 leap may, around 5 am, this time was not accurately reported. There are two hours around five o'clock, Yin Shi before five o'clock and Chen Shi after five o'clock. Below I list all the branches around five o'clock. You just need to choose according to the time of birth.
Lunar calendar: the second day of May in Gengwu (Yin Shi).
Main branch: Gengwuren Wugengshen (Wuyin) Bazaar.
Gregorian calendar:1June 24, 990, Cancer on Sunday.
Source of information: Central China Moon Network