Probabilities of an employee preferring a working week of five days (weekpreference = 3; left panel) and six to seven days (weekpreference = 4; middle panel) for different levels of average daily hours of sleep; probabilities of an employee preferring working days to start and end at a fixed time (daypreference = 1; right panel) for different levels of morningness–eveningness rMEQ (with 90% confidence intervals, other variables at means)