Why do people work intermittently and why do they synchronize their work schedules? A group of interacting workers who differ in tastes is analyzed. A lifetime labor supply model is developed which combines tiring, rhythmic changes in the environment and interactions among workers, arising from communication and coordination. A multiplicity of synchronized equilibria arises. These equilibria can be ranked according to the length of the work period. Equilibria with longer hours are preferred by all workers in the group. The worker with the highest aversion to work sets the standard and others conform to him.