We develop a theoretical framework to analyze the effects of immigration on native job amenities, focusing on work schedules. Immigrants have a comparative advantage in production at, and lower disamenity cost for nighttime work, which leads them to disproportionately choose nighttime employment. Because day and night tasks are imperfect substitutes, the relative price of day tasks increases as their supply becomes relatively more scarce. We provide empirical support for our theory. Native workers in local labor markets that experienced higher rates of immigration are more likely to work day shifts and receive a lower compensating differential for nighttime work.