The answer to the three days is this:
Friday: crucifixion... death approximately 3PM . At the moment of death, Christ's spirit descends to hell. Before sundown, Christ's body is placed in the tomb. The FIRST DAY.
Sundown Friday: When the last glimmer of sun disappears, the Sabbath starts (Jews count days from sundown to sundown). Jesus's body is still in the tomb. It is now Saturday, the SECOND DAY.
Sundown Saturday: Sabbath is over, it is now Sunday. Sometime before the women arrive after dawn with their jars of ointments and salves to treat the body, the resurrection occured, the stone is rolled back, etc. This is the THIRD DAY
The Biblical accounts relate that Jesus arose ON THE THIRD DAY, not that he spent 72 hours in the tomb! "on the third day" implies that His rising could occur anytime after the the last glimmer of sun disappeared the night before.
As a final nail in the coffin of a Wednesday crucifixion, the Bible is explicit that it occured the day before the Sabbath... and Sabbath is the last day of the week: Saturday, not Thursday.