|The divine comedy|
“”As in all cases, the findings of science are far more awe-inspiring than the rantings of the godly. The history of the cosmos begins, if we use the word "time" to mean anything at all, about [13.8] billion years ago. If we use the word "time" wrongly, we shall end up with the infantile computation of the celebrated Archbishop James Ussher of Armagh, who calculated that the Earth — "the Earth" alone, mind you, not the cosmos — had its birthday on Saturday, October 22, in 4004 BC, at six in the afternoon. This dating was endorsed by William Jennings Bryan, a former American secretary of state and two-time Democratic presidential nominee, in courtroom testimony in the third decade of the twentieth century.
|—Christopher Hitchens, God Is Not Great: How Religion Poisons Everything|
He is most famous for calculating what was believed, at the time, to be the exact first day of creation based on a detailed examination of the Bible and of older chronologies and calendars. The date which he arrived at — the night preceding October 23, 4004 BCE — is still used by many young earth creationists today.
 Ussher's chronology
The chronology Ussher devised gives the following biblically identified dates for important events.
- Sunday October 23, 4004 BC - First day of creation.
- Monday November 23, 4004 BC - Adam and Eve driven from paradise.
- 2348 BC - The Great Flood.
- 1921 BC - God's call to Abraham.
- 1491 BC - The Exodus from Egypt.
- 1012 BC - The founding of the Temple in Jerusalem.
- 586 BC - The destruction of Jerusalem by Babylon and the beginning of the Babylonian Captivity.
- 4 BC - The birth of Jesus.
 Biblical disagreements
The main distinction between Ussher and other significantly different (i.e. in the hundreds of years) biblical chronologies depends on which Old Testament version is used.
As with most Protestant bibles today, Ussher relied on the Masoretic text. However, the Eastern Orthodox and older Catholic bibles as well as ancient Christians prior to Jerome tend(ed) to use the Septuagint which moves the date of Creation back to around 5000-5500 BC, but places the Flood much later (around 1850 BC).
A third option, using the Samaritan Pentateuch, while locating Creation (in 4064 BC) almost simultaneously to the Masoretic text, moves the Flood back to around 2800 BC (or about 450 years prior to Masoretic calculations).
A few, more modern (and fringe) biblical chronologies have moved Creation back significantly, such as Harold Camping's 11,013 BC, or two 19th century calculations of, respectively, 12,500 BC and 20,000 BC. Go biblical inerrancy!
 See also
 Further reading
- Barr, James, 'Why the World Was Created in 4004 B.C.: Archbishop Ussher and Biblical Chronology', Bulletin of the John Rylands University Library of Manchester, vol. 67, pp. 575-608
- Gould, Stephen Jay, 'Fall in the House of Ussher', Natural History, vol. 100 (November 1991), pp. 12-21