No, the Passover lamb was sacrificed and roasted in the evening of the 14th (before Mincha time) and it was eaten that evening which would have been the 15th of Nissan.
This day of preparation... Dude, if you actually understood what Jews DO in preparation for Passover, this would not be such an issue, except for those who wish to believe whatever they will to make their agenda of believing what they will about Jesus work.
On the 14th of Nissan, Jews have to stop eating Chametz, or simplistically, leavened bread. Thus, it is IN PREPARATION, yes, but it isn't a special holiday.
It is a day that the First Born Jews fast, in commemoration of the fact that the first born of the Egyptians died in the plague, but the Jews were NOT killed. It's still not a special holiday.
During Temple times, people brought their lambs for the Passover offering and the Chagiga offering to be slaughtered and processed before Mincha (afternoon daily offering and prayer service) on the 14th, so that they could be prepared for dinner that night, which would be the 15th.
If you want to say that "people made a day of it," as the whole day was spent in preparation for Passover, I'll buy that. (Which, frankly, makes Jesus' whole turning of the money-tables entirely unforgivable, and it is a sin Jesus committed that will forever make me despise the mention of the man.)
But no, it was never a special, separate holiday. It is only so in the hearts and minds of Christians who don't bother with what Jews ACTUALLY do, or HAVE done, but wish to continue to propagate misbegotten ideas that were spawned from bad translations to start with.
If the evidence is clear that Jesus ate the Passover meal, that would have been the 15th. When the sun rose, it would ALSO have been the 15th.
If the idea is being spread that Jesus ate a meal that was not the 15th of Nissan, it was clearly not a Passover seder.
You can't have it both ways, no matter what you wish to believe.
I just addressed this. If it was before the 15th, it wasn't Passover.
What I DO want is to clarify when Passover is. If Jesus ate a big meal before Passover, cool. If the meal Jesus had was a Passover seder, good for him. It's no skin off my nose, either way.
But don't try to remake the Jewish calendar to fix a textual problem you have if the gospels didn't manage to make everything nice and neat.
Passover is only as I've described it. If you have come up with anything else... It could be Charlie, it could be Shirley, but it WON'T be Passover.
Sometimes Passover is referred to as Pesach, and sometimes it is referred to as the Holiday of Matza.
Believing that Passover is some other bizarre thing because you are caught up in bad translations... would explain a lot, but it doesn't mean that you have a clue about what Passover IS, or when it is.