An electronic multiple-setback thermostat for residential and commercial use includes an internal clock having a week-long cycle. The thermostat is programmed by the operator, usually manually actuable input devices, to control the furnace/air conditioning system to achieve a schedule of temperatures...http://www.google.com/patents/US4469274?utm_source=gb-gplus-sharePatent US4469274 - Electronic thermostat with repetitive operation cycle
