To provide an imaging system, an apparatus and a method for managing an operation hours and a storage medium whereby a power source for multifunction devices which become unnecessary depending on time zones is turned off while a power source for multifunction devices which become necessary is turned on by managing the operation hours of every time zone of each multifunction device and learning an availability factor, so that power consumption can be restricted to a necessary minimum and energy can be saved.

A host computer 108 monitors an operating state of each of multifunction devices 100-1 to 100-N, counts and totals operating times, and controls to turn off by a device controller 103 the power source for multifunction devices not used for predetermined time zones and to turn on by the device controller 103 the power source for multifunction devices used from predetermined time zones.