From Andreas J. Köstenberger and Justin Taylor at First Things:
In our new book, The Final Days of Jesus: The Most Important Week of the Most Important Person Who Ever Lived, we assume but do not argue for a precise date of Jesus’s crucifixion. Virtually all scholars believe, for various reasons, that Jesus was crucified in the spring of either a.d. 30 or a.d. 33, with the majority opting for the former. (The evidence from astronomy narrows the possibilities to a.d. 27, 30, 33, or 34). However, we want to set forth our case for the date of Friday, April 3, a.d. 33 as the exact day that Christ died for our sins.
To be clear, the Bible does not explicitly specify the precise date of Jesus’s crucifixion and it is not an essential salvation truth. But that does not make it unknowable or unimportant. Because Christianity is a historical religion and the events of Christ’s life did take place in human history alongside other known events, it is helpful to locate Jesus’s death—as precisely as the available evidence allows—within the larger context of human history.
Among the Gospel writers, no one makes this point more strongly than Luke, the Gentile physician turned historian and inspired chronicler of early Christianity.
The Year John the Baptist’s Ministry Began
Luke implies that John the Baptist began his public ministry shortly before Jesus did, and he gives us a historical reference point for when the Baptist’s ministry began: “In the fifteenth year of the reign of Tiberius Caesar . . .” (Luke 3:1).
We know from Roman historians that Tiberius succeeded Augustus as emperor and was confirmed by the Roman Senate on August 19, a.d. 14. He ruled until a.d. 37. “The fifteenth year of the reign of Tiberius Caesar” sounds like a straightforward date, but there are some ambiguities, beginning with when one starts the calculation. Most likely, Tiberius’s reign was counted either from the day he took office in a.d. 14 or from January 1 of the following year, a.d. 15. The earliest possible date at which Tiberius’s “fifteenth year” began is August 19, a.d. 28, and the latest possible date at which his “fifteenth year” ended is December 31, a.d. 29. So John the Baptist’s ministry began anywhere from mid-a.d. 28 until sometime in a.d. 29.