On What Day Was Jesus Crucified?
That depends on which gospel account you read. The writer of John’s account has Jesus eating the Last Supper on the Day of Preparation (14th of Nisan [Jewish calendar]), the day before the Passover so that he would be crucified on the Passover. That scenario has Jesus buried for two nights and resurrected on first day of the week (Jn. 20:1).
However, in the Synoptic accounts (meaning "seeing together -Matthew, Mark, Luke) Jesus ate the Passover meal with them (15th of Nisan); in which case he would have eaten the Passover with them on Friday, been tried and crucified on the Sabbath and buried for only one night (Matt. 26:17-30, Mk. 14:12, Lk. 22:7-14).
Compare again with the writer of John’s account (13:1-2), Jesus ate his last supper with his disciples the day before the Passover; the evening meal was in progress, not the Passover. In this account Jesus was crucified on the Passover and never ate that meal with them. The Jewish leaders and Caiaphas the high priest brought Jesus before Pilate early in the morning so they could eat the Passover meal (Jn. 18:28). Jesus was crucified the same day and his body taken down from the cross before the Sabbath began at 6 PM.
Are the Synoptic accounts correct or is John's account? This is a pretty big discrepancy.
There are many implications. If John's is correct, then the following events as recorded in Matthew 26:17-19 never happened:
17 Now the first day of the feast of unleavened bread the disciples came to Jesus, saying unto him, Where wilt thou that we prepare for thee to eat the Passover?
18 And he said, Go into the city to such a man, and say unto him, The Master saith, My time is at hand; I will keep the Passover at thy house with my disciples.
19 And the disciples did as Jesus had appointed them; and they made ready the Passover.
Implication: It would make the above dialogue fictitious.
But if Matt, Mk and Lk are correct then it would make the following from John 18:28 fictitious:
28 Then led they Jesus from Caiaphas unto the hall of judgment: and it was early; and they themselves went not into the judgment hall, lest they should be defiled; but that they might eat the Passover.
28 Then led they Jesus from Caiaphas unto the hall of judgment: and it was early; and they themselves went not into the judgment hall, lest they should be defiled; but that they might eat the Passover.
Which is it? They can't both be right.