Emperor Constantine and the Calendar
Constantine had more to do with the calendar than simply placing the sanctity of the Sabbath on the first rather than the seventh-day of the week.He restructured the entire calendar. He took the Roman unbroken cycle of eight-day weeks and turned it into an unbroken cycle of seven-day weeks. Saturn's day which had always held first position as the first day of the eight-day week, was now commissioned to the seventh-day.