ABSTRACT

Recorded history confirms that humans have an enduring interest in improving the ways they schedule their work. Historically, this is manifest as a persistent effort to find ways that schedule work to reduce fatigue, improve recovery, and increase time for leisure activity. However, as society and industry develops and expands, there is most often a growing demand for around-the-clock continuous services. The clock, the 8-hour workday, and the 5-day work week can all be considered as good examples of serious and premodern-science efforts to schedule work better and at the same time respond to increasing demands for services. Scientific interest in the schedules of workers was aroused by wartime problems (Taylor 1969), dramatic changes in shiftwork use (International Labour Office, 1978), and the emergence of chronobiology as a respected scientific approach (US Congress, Office of Technology Assessment 1991).