My understanding of the Gospels and the Epistles is that we're not supposed to get deeply into the Sabbath bit anyway - see the episode where they go through the cornfield and the statement "the letter slayeth but the spirit giveth life". 5th century inhabitants of Gaul seem to hedged their bets by fasting and abstaining from work on Saturday and then going to church on Sunday (Catholics, that is - the Arians seem to have gone every day)