This study uses nationally representative data for the United States from the Basic Monthly Current Population Survey to document how teachers' hours of work have changed in 2020 and 2021 relative to typical labor supply levels and to the hours worked by other college-educated professional workers. Controlling for demographics, teachers' hours decreased early in the pandemic, but throughout the 2020-2021 school year teachers have been working more than usual. The increase is slightly more pronounced for veteran teachers and for females. The findings emphasize the increased demands of the teaching profession during the global pandemic.