ABSTRACT
It is increasingly common to find people working during shifts that differ from the traditional 9-to-5 hours. The term shiftwork loosely subsumes the range of different work schedules, including night work, rotating shifts which change periodically, split shifts (two work periods per day) and other arrangements which vary significantly from fixed daytime hours. Because such schedules, particularly rotating and night work, may interfere with the normal wake-sleep cycles, there has been great interest in their effects on physiologic functioning, overall health, safety, productivity, and social well-being. The design of a work schedule is an important consideration for any organization which requires continuous production or coverage of functions during the evening and night hours. Unfortunately, schedule design is not always a straightforward exercise, and there are trade-offs which must be made between physiologic factors and social preferences.
