This chapter examines the evolution of working conditions in pre-industrial Normandy, focusing on the longstanding debates over working time and public holidays. During the Middle Ages. theologians like Nicolas de Clamanges criticised the rising number of non-working religious days, arguing that they promoted non-religious behaviour and harmed poor workers. This debate persisted in the following centuries, particularly between Catholic and Protestant intellectuals. More recently, seminal works in economic history have emphasised the significance of working days for our understanding of past living standards, prompting further methodological refinements. Using new data on religious holidays and payment records, we assess the actual versus theoretical working days in Normandy from the fourteenth to the eighteenth century. Our analysis suggests that the common assumption that 250 working days per year was the norm for many labourers during the late Middle Ages. This figure seems, however, higher for the later period. By the mid-eighteenth century, it was not uncommon for individuals to work as many as 290-300 days per year. We further explore changes in labour regulations to document daily working conditions, showing that working hours increased by one to two hours per day between the Middle Age and the late eighteenth century. While we focus on Normandy, an important commercial and industrial centre in France, we believe this study offers valuable insights into the economic history of early modern Europe.