This study establishes empirically a positive but nonlinear relationship between weekly hours and hourly wage growth. For workers who put in over 47 hours per week, 5 extra hours are associated with a 1% increase in annual wage growth. This correlation is not present when hours are lower. The relationship is especially strong for young professionals. Data on promotions provide evidence in support of a job-ladder model that combines higher skill sensitivity of output in higher-level jobs with heterogeneous preferences for leisure. The results can be used to account for part of the gender wage gap.