<unk>  is an employment practice designed to make use of the 24 hours of the clock, rather than a standard working day.  The term<unk>  includes both long-term night<unk> s and work schedules in which employees change or rotate<unk> s.
A related yet different concept,  the work<unk> , is the time period during which a person is at work.
Shift work
Work aversion
Dipping tobacco
Passive smoking
Physical exercise
Special education
Sedentary lifestyle
Moral hazard