This paper studies competition in prices and opening hours in a model with free entry. It is shown that under free competition a market failure arises: Entry is excessive and opening hours are under-provided. Restrictions on opening hours aggravate this failure. I analyze the impact of a liberalization of opening hours. The model predicts that in the short run prices will remain constant, but increase in the long run. Concentration in the retail sector will rise and opening hours will increase in two steps, immediately after deregulation and further over time. Finally, employment in the retail sector increases.