the present overview on existing research addresses the double implication of working-time standards as legal (or contractual) norms, on the one hand, and socially established normality, on the other. Looking primarily at the evidence on the statutory 35-hour week in France, the author discusses the question of how changes in norms as stipulated by law or collective agreements may affect working-time practices in the society. given the specific institutional and policy tradition of statist intervention in France, a comparison with the effects of the contractual 35-hour week on actual hours in the West german metal industry highlights particular strengths and weaknesses of the French approach. While the empirical evidence underscores the crucial importance of statutory norms and the interaction between governments and social actors, it equally reveals the increasing difficulties to set limits to normal hours for growing shares of the workforce just by setting statutory or collective norms. the transformation of new working-time norms into normality leading to a generalized shorter standard workweek is a long-term social process that requires continual intervention of actors at various levels and must be embedded in agreements both at the workplace and within households. C hanging working-time standards takes time. If we look back at workingtime developments in the capitalist world in general and in 20th-century europe in particular, it is easy to distinguish two major long-term trends. the first, and fundamental, change was the step-by-step establishment of the 8-hour day and, later, the 40-hour week as a legally mandated or widely adopted contractual standard. this was accomplished by the 1970s or 1980s in large parts of europe (much earlier in the United states) and by the 1990s and early 2000s in eastern europe and Portugal. the second trend, which has gained ground over the last 20 or 30 years, is the proliferation of nonstandard working hours above and below the 40-hour standard across many countries and industries.In most countries, once the 40-hour week was established, the general push for shorter standard work hours lost momentum. While some trade * steffen Lehndorff is Research Fellow at the University of Duisburg-essen. many thanks to Peter Berg, gerhard Bosch, Jean Charest, michel Lallement, eleonora matteazzi, François Rycx, and two anonymous reviewers for their valuable suggestions. Correspondence can be directed to steffen.lehndorff@uni-due.de.