%0 Report %A Cardoso, Ana Rute %A Hamermesh, Daniel S. %A Varejão, José %T The Timing of Labor Demand %D 2008 %8 2008 Dec %I Institute of Labor Economics (IZA) %C Bonn %7 IZA Discussion Paper %N 3885 %U https://www.iza.org/index.php/publications/dp3885 %X We examine the timing of firms' operations in a formal model of labor demand. Merging a variety of data sets from Portugal from 1995-2004, we describe temporal patterns of firms' demand for labor and estimate production-functions and relative labor-demand equations. The results demonstrate the existence of substitution of employment across times of the day/week and show that legislated penalties for work at irregular hours induce firms to alter their operating schedules. The results suggest a role for such penalties in an unregulated labor market, such as the United States, in which unusually large fractions of work are performed at night and on weekends. %K labor demand %K time use %K wage penalty