Yes, the Department of Energy recommends a change of no more than 3 degrees for maximum possible energy savings. These 3 degrees are critical because if you allow your home to get warmer or colder than this, it will result in your unit having to work extra hard to return your house to the proper temperature. This period of extra hard work for the unit will eliminate all the cost you saved throughout the day and will now cost you more overall. This is especially true in the summer. For example, if you were to turn your unit off while you were at work and the house temperature rose 5 degrees, when you return home and crank down the thermostat, your unit now has to work twice as hard to remove all the extra heat in the home during the hottest time of the day. This results in massive energy usage and cost.