I think they had Sundays off for religious reasons, but not sure how much choice peasants or farmers had given fields need clearing, seeds need planting, crops needed harvesting and animals needed caring, reproducing, feeding, butchering and preserving, irrespective of day of week.
Slacking on any of the above could result in starvation the coming Winter as well as possibly losing your animals as well. There was lots of interdependencies which were quite unforgiving.