The origin point for nearly all of those “you work harder than a medieval peasant” memes and articles is Juliet Schor’s The Overworked American (1993). The argument has been debunked quite a few times, so I won’t belabor the point here. Schor bases her estimates of medieval working hours on a 1935 article by Nora Kenyon, and an unpublished article by Gregory Clark, and in both cases ignores the authors’ careful efforts to distinguish between total days worked and instead just cherry-picks the lowest number, even as the authors caution that those numbers likely don’t represent someone’s total employment. Kenyon notes a set of day-laborers working 120 days per year which makes it into Schor’s work, but Kenyon’s final suggestion that the normal annual working year was 308 days does not, for instance. I can’t get at an unpublished article, but Clark has continued to write on the topic and in his 2018 “Growth or stagnation?” presents a detailed argument for a 250-300-day work-year with no sense that this is a revision of his previous positions, leading me to suspect similar cherry-picking as with Kenyon.
In short, Schor’s works is quite shoddy and we shan’t rely on it.
Now part of the complication there is that for the European Middle Ages, across so much area, what we see is a lot of confusing evidence – statutory minimums, required labor on a lord’s land and so on – which may or may not represent a full working year. What we don’t typically get is someone just telling us how many work days were in the agricultural calendar. But as you may recall, we’re anchoring this discussion in the Roman world and in a rare instance where the ancient evidence is better, Roman agricultural writers just straight up tell us how many working days there were in a year on the Roman agricultural calendar: 290 (Columella 2.12.8-9). He allows 45 days for holidays as well as inclement weather and another 30 days for rest immediately after the crop is sown, to recover from the difficult labor of the final plowing.
The medieval work calendar is not meaningfully different. As noted above, Both Clark and Kenyon end up with similar working-day estimates from the medieval evidence as Columella’s figure. The medieval number is probably slightly lower: the medieval religious calendar might have around 45 feast days but workers might also be expected to spend Sundays in religious observance, which might pull the work-year down to around 270 total working days, plus or minus.
By all evidence, those working days were both less rigid but also longer than modern working hours. On the one hand, peasant farmers are essentially self-employed entrepreneurs, making their own hours. They can arrive in the field a bit late, sometimes leave a bit early. It was certainly common in warmer climates for workers to take a midday break (a siesta) to avoid exhausting themselves in the hottest part of the day. I will say, anyone who has done functionally any outside work in a warm climate will recognize that a midday break can allow you to work more than just pushing straight through the heat of the day because you tire more slowly.
So on the one hand the work hours are somewhat flexible. On the other hand as functionally anyone who has ever worked on a farm or spoken with someone who has will tell you, the working day in absolute terms is long, essentially starting at sunrise and running to sunset. And this is certainly the implication we get from our sources. Because of atmospheric refraction, there are actually slightly more than 12 sunlight hours per day on average (it’s around ~12.3 or so, depending on latitude), though this of course varies seasonally. The bad news for our farmers, of course, is that the shortest days are in the winter when the labor demands are lower. While festival calendars feature events throughout the year, it is not an accident that major festivals in a lot of pre-modern agrarian cultures are concentrated in late Fall, winter and early Spring. For the Christian calendar, that includes things like All Saints Day (Nov 1), Martinmas (Nov 11), the regular slew of December holidays as as the holidays of the Eastertide in early spring. For the Romans, you have major festivals like the Parentalia and Lupercalia in February, the Liberalia in March, the Cerialia in April and the Saturnalia in December.
So in practice the average maximum working day might actually be a bit longer than 12 hours, but we should account for breaks and general schedule flexibility. We might assume, for comparison, something like a ten hour work day. By that measure, our peasants probably put in somewhere between 2,500 and 3,000 working hours per year. By contrast, your average ‘overworked American’ has 260 working days a year, at eight hours a day for just 2,080 hours.
So to answer the question: no, you do not work more than a medieval (or ancient) peasant (despite your labor buying a much higher standard of living).
Bret Devereaux, "Life, Work, Death and the Peasant, Part IVb: Working Days"
