John 19:31 Now it was the day of Preparation, and the next day was to be a special Sabbath. Because the Jewish leaders did not want the bodies left on the crosses during the Sabbath, they asked Pilate to have the legs broken and the bodies taken down.
According to John, the day of Preparation was the day that Jesus was crucified.
Matthew 26:2 "As you know, the Passover is two days away--and the Son of Man will be handed over to be crucified."
Matthew 26:17 On the first day of the Festival of Unleavened Bread, the disciples came to Jesus and asked, "Where do you want us to make preparations for you to eat the Passover?"
Matthew 26:65 Then the high priest tore his clothes and said, "He has spoken blasphemy! Why do we need any more witnesses? Look, now you have heard the blasphemy.
Matthew 27:62 The next day, the one after Preparation Day, the chief priests and Pharisees assembled before Pilate.
According to Matthew, Preparation Day was the day before Pilate's gave permission to secure the tomb. Then Preparation Day was the day Jesus was crucified and they ate the last supper on the day before the Preparation Day. Jesus and his disciples could not have eaten the sacrificial lamb in the last supper.