1990 What's the date of the first day of the eighth lunar month?

Maybe it's a typo.

1990 The Gregorian calendar date of the first day of the eighth lunar month is1September 9901Wednesday.

Lunar calendar: the first day of August in Gengwu.

Branch: Gengwu Yiyou Dinghai

Gregorian calendar:1September 9901September Wednesday Virgo.

Source of information: Central China Moon Network