If Saturday is the day of rest, it should be the day of worship - that way people are off work and can attend church. The fact that Sunday has been the universal day for worship in almost all denominations for centuries proves the point - for a Christian, Sunday is the Sabbath. The seventh day, Sunday. I'm counting back. Sunday is the day of rest and has been seen that way by Christians for a very long time now. That makes Sunday the last day ("On the seventh day He rested") and counting back Monday is the first day.