Work as long as it is possible to be productive, safe and alert in the workplace. When it comes to safety, it is imperative to be aware of one's surroundings and to be on task.
Extra hours at work must come from somewhere: Sleep tends to be the area that suffers, according to The New York Times. Trading sleep for work time is a bad idea; a safe work environment requires that employees be well-rested. Too much overtime sometimes causes accidents.
The New York Times mentions a University of Pennsylvania study run from 2003 to 2011 to explain that many Americans lose sleep in order to get to work earlier. However, the benefits are negligible. These early hours are less productive, and the lack of sleep also affects workers' bodies and alertness.