Alexander Wedderburn Heriot--Watt University
Time-of-day has gradually appeared more and more in the research literature over the past 20 years, so that there is now a substantial body of research, as well as practical experience, that documents what is involved in working at different times of day. For example, human bodily functions are certainly affected by time of day. Human social activities are equally important for most people, and are also obviously geared to times of the day, and also to days of the week. The impact of time on work cannot be ignored.
In response to this growth of knowledge, there has also been a growth in attempts to apply it to practical situations, from dealing with jet lag to the design of shiftwork systems. This chapter reviews this knowledge from the point of view of practical police requirements, without concealing the continuing controversies on many matters. It should be noted that there have been a few published studies of police work at different times of day. These are mentioned where relevant, but are not the main or only database for this chapter. In the author's opinion, police work varies considerably from country to country, and indeed from locality to locality within a country, so that generalizations developed in one time and place will not necessarily give a good fit in another.
Police organizations also tend to develop a strong "culture," which often includes the belief that police shiftwork is quite different from any other kind of shiftwork. So police in Australia and the United Kingdom readily pick up a police shift system, the Ottawa system, from Canada, but pay less attention to other shift systems on their doorsteps.