Macrophage eats a common misconception about when young earth creationism came on the scene and what ancient Christians really believed about the age of the earth, the days of creation, and the relationship between science and the Bible. 

References in the order of appearance:

Theophilus of Antioch, To Autolycus, Book III, Chapter XXVIII, Leading Chronological Epochs, ~180 A.D.

https://www.earlychristianwritings.com/text/theophilus-book3.html

Julius Africanus, Chronography, Fragment 18:4, 221 A.D. https://www.newadvent.org/fathers/0614.htm

Origen, Contra Celsum, Book I, Chapter XIX, 248 A.D. https://www.earlychristianwritings.com/text/origen161.html

St. Augustine, City of God, Book XII, chapter 10, "Of the Falseness of the History Which Allots Many Thousand Years to the World's Past", 426 A.D. https://www.newadvent.org/fathers/120112.htm

Johannes Kepler, Book V, The Harmony of the World, 1619 A.D.

Hippolytus of Rome, Fragments, On Daniel II:4-6, ~ 205 A.D. https://www.newadvent.org/fathers/0502.htm

Irenaeus, Against Heresies, Book 5, Chapter XXVIII:3 ~ 180 A.D. https://www.earlychristianwritings.com/text/irenaeus-book5.html

Basil, Hexaemeron, Homily II:8 , ~370 A.D. (commentary on Gen. 1:5) https://www.newadvent.org/fathers/32012.htm

Augustine, De Genesi ad Litteram, 1.19.39, Taylor, J.H., translation and annotation of St Augustine, The Literal Meaning of Genesis(Augustine, De Genesi ad Litteram), Vol. 1, Newman/Paulist Press, New York, 1982. 

Irenaeus, Against Heresies, Book II, Chapter II, The World Was Not Formed by Angels, or by Any Other Being, Contrary to the Will of the Most High God, But Was Made by the Father Through the Word, Part 5, ~180 A.D. https://www.newadvent.org/fathers/0103202.htm

Irenaeus, Against Heresies, Book II, Chapter XXVIII, Perfect Knowledge Cannot Be Attained in the Present Life: Many Questions Must Be Submissively Left in the Hands of God, Part 2,~180 A.D. https://www.newadvent.org/fathers/0103228.htm