The constitutional qualification of Sundays and public holidays as days of rest and spiritual elevation reflects a long and tumultuous legal development. It ranges from the Old Testament commandment of holiday sanctification to the establishment of non-working days as a socio-political achievement of the industrial age. Through selected aspects, the author outlines the intellectual historical factors, political conflicts, and socio-economic transformations that have shaped the development of Sunday and holiday law and continue to influence the discussion around Sunday and holiday protection to this day. The focus of the presentation is on the legal development since the beginning of the 19th century. Central to the examination are particularly the socio-political disputes over the enforcement of rest from work on Sundays and public holidays in the 19th century and the treatment of Sundays and public holidays in the ideological dictatorships of the 20th century.