The current literature on the economic cost of air pollution in the labor market primarily focuses on labor productivity, leaving the impact on working hours relatively unexplored. In this paper, we investigate the effects of air pollution on work hours using a nationally representative sample for Chile. To address the potential endogeneity of air pollution, we leverage the exogenous occurrence of wildfires between 2010 and 2018. We construct the smoke plumes originating from each wildfire to identify the causal impact of air pollution on hours worked. Our analysis reveals that an exogenous increase in fine particulate matter resulting from an extra smoky day leads to a 2% reduction in work hours for the average Chilean worker. The impact is more pronounced for male workers engaged in outdoor tasks, such as agriculture, and for economically disadvantaged households, where the negative effects of air pollution can be up to four times larger. Our findings imply that earlier studies focusing only on labor productivity may be underestimating the effect of air pollution on economic output by 11-13%.