Any direct comparison between the labour of medieval peasants or craftsmen and modern workers is largely not possible due to the completely different character of these two types of labour organization. Please note that today, in developed countries, whether capitalist, communist or adopting a different form of economic principles, the most common way of working is a wage labour based on an employment contract and strict division between the performance of labour and ownership of means of production. In other words, most people work by performing specific tasks for the persons (physical or legal) who own the means of production used to generate value and then receive a remuneration for the work done, usually in form of money they can spend freely. Such organization of labour, completely obvious to modern people, was something highly unusual in Middle Ages though.
Modern organization of labour is largely shaped by the industrialization that separated the work from its results, at least from the perspective of the workers involved. In an industrial setting, workers were obliged to work their shift, i.e. an artificially set amount of time, producing goods that were a property of the factory owner. Thus, there was no ‘start’ and ‘end’ of the work that theoretically could have been conducted all year round, without pause, if the shifts were organized so and demand for the product warranted such supply intensity.
Now, this is a far cry from how the labour looked like in the Middle Ages. In opposition to the workers in the industrial and post-industrial settings, most peasants and craftsmen were essentially sole traders, who were utilizing their assets that were either owned (especially in case of urban craftsmen) or loaned (usually in the case of peasants) to generate wealth for themselves and were only obliged to pay taxes determined by the local authority. It should be noted however, that the ‘taxes’ might have not necessarily been the part of produce or a specific sum of money, but also various services, such as forest clearing, transportation of goods or fortification maintenance.
It is sometimes said that in the Middle Ages (and in early Modern period), holidays could have amounted up to a third of the year. This is true, but it does not differ that much from the situation most modern workers from developed or developing countries are in. They usually work a standard 40-45 hours per week, meaning 8-9 hours of work on each of the five days, and the free Saturdays and Sundays alone contribute to 104 free days. In Europe, most countries have roughly 8 national or religious holidays each year with 20-25 days of paid vacation on top of it, bringing the average number of free days to 135 or 37% of all the days in a year. Sure, some countries have e.g. less leave holidays or vacation days, but it still gives us one-third of the year being free from work.
Now, the principal work of the medieval peasants was usually more complex than it is sometimes presented, as it is not uncommon to assume that peasants were only farmers and their fields were unicultural (i.e. only one type of crops were grown there). This is not really correct. Agricultural production almost everywhere in Europe was localized, meaning that all products local people needed and that could have been obtained in a given place, were produced locally, requiring farmers to grow various crops simultaneously. As the medieval farmers were using crop rotation techniques, usually two-field system known in the Early Middle Ages or three-field system introduced in the times of Charlemagne and popularized across Europe only in the High Middle Ages (four-field system was introduced in 18th century), they were sowing and harvesting twice a year at a minimum. In reality there were much more crops with a different vegetation times, with winter cereals, spring cereals, lentils, rape, flax and hemp being the most common. Agricultural work was not limited to field work though, as virtually every homestead had a vegetable garden where every family was growing various plants for their own use (various tubers, herbs, root vegetables, cabbage, cucumbers etc.) that required occasional tending.
Second, in most homesteads peasants were keeping at least some animals. Hens were ubiquitous as they were low-maintenance, relatively cheap, could reproduce rather easily and acted as an important source of protein (eggs and meat). Cows, sheep and sometimes goats were a source of dairy products. Pigs were raised for meat and leather. Horses and oxen were, of course, ubiquitous working animals. All these animals had to be tended to daily and feeding, mucking, brushing, milking, collecting eggs and related activities were an important part of a daily routine for most peasants. Larger herds had to be led to a pasture, guarded and then brought back making this was an all-day job, quite often delegated to younger people in case of smaller animals. Just to put the amount of work in perspective, an average modern cow requires about 60 litres of water per day, so taking into account the projected differences in size of the medieval farm animals might have meant 30-40 litres per animal that had to be provided in the days when the animals were not grazing. Hauling such amount of water from a nearby source (usually river or stream, as wells would have quickly run dry) might have taken a dozen of trips every day.
Third, as I wrote above, the villages were largely self-reliant, especially in the Early Middle Ages, what means that everything had to be produced by peasants themselves and this includes their very literal daily bread. But even such staple food as bread or oatmeal required preparation from scratch and firing up the primitive stove was in itself a long task given the technology available, so preparation of a decent meal for the entire family could have taken a significant part of a day. On a rare occasion, when the animal was slaughtered, meat and leather had to immediately processed to avoid spoiling - cutting, mincing, sausage-making and smoking could have taken days, depending on the number of people involved. Thus, preparation of food for the entire family could have been construed as a full-time job for a single person, what have not really changed until the introduction of refrigerators, gas and electric stoves and various modern kitchen appliances, what in some rural areas could mean times as close as second half of 20th century.
Of course, food was not the only thing that was made by peasants, who also had to create their agricultural tools used for all the work in the fields and around the house, such as rakes, flails, plows, carts or wheelbarrows. The same can be said of simple containers and utensils, from baskets to spoons to troughs. Carving the wooden tools, forming and firing clay bowls and jars, basket weaving, candles casting - all of these also consumed a lot of time. Clothing was often made locally, what required preparation of materials, and fulling, breaking, carding, spinning, weaving and finally cutting and sewing new garments were a tedious activities usually done in the long evenings, as they were primarily indoor work. With the development of the economic networks and increased amount of money in circulation, more and more goods were simply bought for the money received from the sale of the surplus agricultural or consumer goods, but as far the Middle Ages.