We propose a consistent estimate of working hours for 1880-2019 – including unpaid work in family farms – delivering U-shaped female hours with a turning point around 1940, and monotonically declining male hours. We model these trends in a multisector economy with uneven productivity growth. The early agricultural decline boosts services and leisure, reducing market work for both genders. In later stages, labor reallocates from manufacturing into home services, and from home to market services. Given gender specialization, male hours continue to decline while female hours increase. Quantitatively, our model replicates the overall hours decline from 1880-1950, and one quarter of later changes. (with Rachel Ngai and Claudia Olivetti)