Today is Good Friday*, the religious holiday memorates the crucifixion of Jesus Christ and his death at Calvary. Christians have celebrated the event for over two millennia. But what was the date of the original Good Friday?

Almost all scholars agree that Jesus was crucified in the spring of either A.D. 30 or A.D. 33. In their book,The Final Days of Jesus: The Most Important Week of the Most Important Person Who Ever Lived, Andreas Köstenberger and Justin Taylor contend that the exact date of the first Good Friday was Friday, April 3 and the first Easter on April 5 A.D. 33.

Their assumption for that date is based on the beginning of Tiberius’s reign (A.D. 14), the beginning of John the Baptist’s ministry in the fifteenth year of Tiberius’s reign (A.D. 28), the beginning of Jesus’s ministry (A.D. 29), and a minimum three-year duration of Jesus’ ministry, putting the most likely date of Jesus’s crucifixion in A.D. 33 (April 3).

“While other dates are possible,” say the authors, “we believers can take great assurance from the fact that the most important historical events in Jesus’s life, such as the crucifixion, are firmly anchored in human history.”

*The historical origins of the “Good” in Good Friday remain unclear, though some entomologists believe the term “good” is an archaic form of “holy.”