Was the Last Supper not the Passover meal? The accepted answer on How long was Jesus in the tomb? would only have been possible if the Last Supper was not the Passover meal, which I had always thought it was.  Was the Last Supper in fact not the Passover meal?
My new understanding of the Last Supper is mostly based on the information at http://www.therefinersfire.org/celebrating_passover.htm.
The key verses which indicate that Christ was actually crucified on the day before the Passover feast are John 18:28 and John 19:14.

John 18:28 NIV
Then the Jewish leaders took Jesus from Caiaphas to the palace of the Roman governor. By now it was early morning, and to avoid ceremonial uncleanness they did not enter the palace, because they wanted to be able to eat the Passover.
John 19:14 NIV
It was the day of Preparation of the Passover; it was about noon.
“Here is your king,” Pilate said to the Jews.

The day of preparation would be when they slaughter the Passover lamb, which would then be eaten that night.