I investigate the optimal timing and length of breaks in a model with fatigue. A break’s length determines the worker’s productivity once work is resumed. I show that all breaks should be identical, equally spaced and long enough to fully recover productivity. When taking breaks is costless, the higher the number of breaks the better. Otherwise, the optimal number is ﬁnite and those workers whose productivity falls more at the beginning of the day should take more breaks. Workaholics take their breaks too early and make them too short, from the employers’ viewpoint. The opposite is true for leisure-oriented workers.
Keywords: Fatigue, Productivity, Hours of work, Breaks, Leisure