Here, how about this:
Links that may answer your questions...
http://www.luxproducts.com/consumer_info.htm
"Programmable thermostats can save energy and save you money on utility bills. According to the the U.S. Department of Energy, a programmable thermostat can reduce heating costs by up to 35% and cooling costs by up to 25%. Your savings will largely depend on the length of your energy saving program periods and the temperatures set. For example, an energy saving period of 10 hours with the temperature set back 10° will save more than a 5 hour energy saving period with the temperature set back 5°"