Do women really sleep more than men? Biomedical and social scientific studies show longer sleep durations for women, a surprising finding given sociological research showing women have more unpaid work and less high-quality leisure time compared to men. We assess explanations for gender differences in time for sleep, including compositional differences in levels of engagement in paid and unpaid labor, gendered responses to work and family responsibilities, and differences in napping, bedtimes, and interrupted sleep for caregiving. We examine the overall gender gap in time for sleep as well as gaps within family life-course stages based on age, partnership, and parenthood statuses. We analyze minutes of sleep from a diary day collected from nationally representative samples of working-age adults in the American Time Use Surveys of 2003 to 2007. Overall and at most life course stages, women slept more than men. Much of the gap is explained by work and family responsibilities and gendered time tradeoffs; as such, gender differences vary across life course stages. The gender gap in sleep time favoring women is relatively small for most comparisons and should be considered in light of the gender gap in leisure time favoring men at all life course stages.