The article focuses on working time policies introduced in Belgium during the period 1975-1990. As a country with early mass-unemployment, the magnitude of the unfolding Labour market problems fostered a specific set of responsive strategies. The initial trajectory of Belgian working time policies was centered around cutting standard weekly working hours in order to enhance Labour market effects. In the course of a marked issue transformation, work sharing objectives were substituted by the notion of temporal flexibility which focused primarily on concerns for and changes in the economie performance of individual firms. The author outlines various structural features of the Belgian socio-economic system and argues that these profoundly affected the goals identified with working time policies as much as the actor constellations endorsing the respective measures.