We study the employment and distributional effects of regulating (reducing) working time in a general equilibrium model with search-matching frictions. Job creation entails fixed costs, but existing jobs are subject to diminishing returns. We characterize the equilibrium in the de-regulated economy where firms and individual workers freely negotiate wages and hours. Then, we consider the effects of a legislation restricting the maximum working time, while we let wages respond endogenously. Employment effects are sensitive to the representation of preferences. In our benchmark, small reductions in working time, starting from the laissez-faire equilibrium solution, always result in a small increase in the equilibrium employment, while larger reductions reduce employment. The regulation benefits workers, both unemployed and employed (even if wages decrease and even in cases where employment falls), but reduces profits and output.