Abstract: Apparatus for providing a percentage time control for the manageable and controllable electrical loads in the home such as air conditioning units, hot water heaters, space heaters and like devices, such apparatus including a master timer or programmer which is connected with the said devices so as to automatically predetermine the time periods of operation thereof in a manner such that a considerable saving in the consumption of electrical energy may be effected by periodically deenergizing the units in a selective manner. The arrangement is also such that the automatic "On-Off" periods of operation of the controlled devices may be readily varied or even interrupted in order to be adaptable to different conditions encountered in the home.