How do you fit 3 days and 3 nights between Friday sundown and Sunday sunrise?

The only sign that Jesus gave that He was the Messiah was the sign of Jonah. ie. that as Jonah was 3 days and 3 nights in the belly of the fish, so Jesus would be 3 days and 3 nights in the heart of the earth. According to the church He could have only been there a maximum of 1 day and 2 nights. Does this mean He was not the Messiah or Have the church got it wrong?