James Ussher's purported creation date of the world according to the Bible.

James Ussher was the Church of Ireland Archbishop of Armagh and Primate of All Ireland between 1625 and 1656. He was a prolific Irish scholar and church leader, who today is most famous for his identification of the genuine letters of the church father, Ignatius of Antioch, and for his chronology that sought to establish the time and date of the creation as "the entrance of the night preceding the 23rd day of October ... the year before Christ 4004"; that is, around 6 pm on 22 October 4004 BC, per the proleptic Julian calendar.