How anyone with a modern brain could possibly think that Bishop Ussher was right boggles the mind. He gave a date of December something, 4004 bc based on his calculation of the number of years in the begats. Since a careful reading of the bible indicates that these were listed as years, not months and days, then it is impossible to come up with a precise date. Rather it is an indication of the need to present the faithful with a date certain in a prescientific culture.
It’s the last chapter in the Fall of the Date of Ussher.
Interestingly and contrary to the fictitious play and movie, William Jennings Bryan didn't adhere to Ussher's calculation, either.