I think it's set up for those that have religious beliefs preventing them from "working" on the Sabbath. "Working" includes such chores as building a fire, or turning on an oven. The Sabbath setting disables the auto-shutoff found on most modern ovens, so that they can start the oven the day before. The theory is that the work to prepare the meal is the day before, and merely "kept warm" on the Sabbath, which is not "working".