Actually the scriptures say he was crucified on the eve of Passover. I'm pretty convinced the eve of Passover for this particular year, a year with 13 months, was on a Wednesday. The actual day of Passover is a High Sabbath day.
There's a bit of controversy concerning this, but after much research, I'm convinced the Wednesay crucifixtion and burial at the eve and start of the High Sabbath (Passover - sundown is the start of a new day for the Jews) is accurate.
This means the Messiah rose at the close of the following regular Sabbath, at sundown. This works out since Mary and the others arrived at the burial site at dawn on the following morning (the 1st day of the week - Sunday).
Also, this Jewish New Year begins the 6015 year (by the original Hebrew Calendar according to some). Another amazing consequence since we are into our '15 year by Western methods of keeping time as well.
As you mention, it really is an unimportant issue central to our faith and salvation, but Scripture definitely points to Jesus being crucified on the Passover as prophesied.
Among other sculptural evidence of this, Jesus, the night he was betrayed, said he desired to eat the Passover with his disciples. The Last Supper was the night of the Passover. That would have been after six oclock (our Thursday night, but the beginning of the next Jewish day (ie. Friday)) so the new Jewish day would have already begun which would have been the same day as the day of preparation, the day before the sabbath (our Saturday).
The Passover meal and crucifixion was prophesied among other things in Scripture by the orginal passover when they killed the Lamb and the blood of the Lamb protected them.