A Cambridge University professor has determined that the Last Supper, the meal that Jesus Christ took part in before his crucifixion, was not on Maundy Thursday, which was widely believed for years. According to Professor Colin Humphreys, it was on a Wednesday. April 1, A.D. 33, to be exact.
If true, it would mean that Jesus’ arrest, interrogation and trials did not occur in just one night. “If you look at all the events in the Gospels record – between the Last Supper and the Crucifixion, there is a large number,” he told BBC News. “It is impossible to fit them in between a Thursday evening and a Friday morning.”
Humphreys believes the finding could make us rethink when to actually celebrate the holiday.
The historical inconsistency, which he says some have called “the thorniest problem in the New Testament,” comes from differing calendars used at the time by Matthew, Mark, Luke and John. The first three all wrote that the Last Supper coincided with Passover, while John claimed it took place before the Jewish holiday.
If Humphreys is right about the differing calendars, the gospels are in actually in agreement about a Wednesday, April 1, Last Supper. An April Fool’s Day Last Supper, that is — so should we be waiting for a punchline?
(More on TIME.com: Read TIME’s 1997 cover story about heaven’s existence)