“Shift work refers to a job schedule in which employees work hours other than the standard hours of 8 a.m. to 5 p.m. or a schedule other than the standard workweek – Monday through Friday in the United States” (Grosswald, 2004, p. 414).
“In general, the term ‘shift work’ is quite vague and includes any organization of working hours that differ from the traditional diurnal work period; sometimes it is a (sic) synonymous of irregular or odd working hours” (Costa, 2003, p. 264).
“…most studies on shiftwork classify shiftworkers as anyone working outside regular daytime hours (i.e. between approximately 7 a.m. and 6 p.m., Monday through Friday). Under these definitions, shiftworkers include all people working evening shift, night shift, rotating shifts, split shifts, or irregular or on-call schedules both during the week and on weekends” (Institute for Work & Health, n.d.).
“The standard workday unfolds during an 8-5 timeframe. We consider shift workers to be individuals who work nonstandard hours.” (Root, 2004)

shift work on family satisfaction. Families in Society: The Journal of Contemporary Social Services, 85(3), 413 - 423. Costa, G. (2003). Factors influencing health of workers and tolerance to shift work. Theoretical Issues in Ergonomics Science, 4(3 - 4), 263 - 288. Institute for Work & Health. (n.d.). Fact sheet - shiftwork. Toronto, CA: Author. Retrieved August 3, 2005, from Pitt-Casouphes, M. (2004, December). An interview with Larry Root and Elizabeth Rudd. The Network News: A Work-Family News Publication, 6(8). Retrieved August 18, 2005, from