explanation. And this explanation might not be entirely groundless.

Mark was written much earlier than John. The author of John (supposedly John the apostle himself) must have read Mark, and John was a traditional jew, so he used the traditional and standard passover meal as a time reference for the crucifixion. Otherwise, John should be aware of the inconsistency and would have avoided it.

I am not a defender of the infallibility of the Bible. In fact, I believe the Bible was written by people and is full of inconsistencies and errors.

hehe