The correct answer is Saturday, October 22, 4004 BC. Just before night-fall. Ussher's proposed date is similar to his contemporary's estimates of 4000 BC by Isaac Newton and 3992 BC by Kepler. These estimates were largely based upon the chronologies and histories presented in Genesis and represent various contributions to a long-standing theological debate concerning the age of the earth. Of course these not all based upon later scientific discoveries that have lead to our current estimate that the universe is about 13.7 billion years old and the earth is around 4.5 billion years old...give or take about 1% (or 50 million years).

Remarkably, Ussher's chronology is used by "young earth" creationists to substantiate their claim that the Earth (and the universe for that matter) is around 6000 years old.