Ahem, 6000 years, approximately.
> around 6 pm on 22 October 4004 BC, per the proleptic Julian calendar.
While the Gregorian calendar was in use for about 70 years by the time of his "calculation" of the age of the Earth, the Gregorian calendar was a Catholic invention and Ussher was very Protestant.
https://en.wikipedia.org/wiki/James_Ussher
Physical evident strongly supports the 13-ish billion year age. Radioactive decay shows that a young earth could not exist, as there would be lots of short-lived primordial radioactive isotopes. Instead, the only primordial radioactives are those with very long half-lives. If there were a different rate of radioactive decay (as some YECs try to suggest), the Earth would still be a molten ball of lava/magma with no solid surface. And definately no liquid water anywhere.