Want to know for sure? Keep doing what your doing for a month or a billing cycle, then leave it at a set temp for the next month/cycle.

On a different note, we monitor different areas of our house with thermometers and it is never a constant temp everywhere in the house. Our termostat (next to the Master BR) is set to 77 all the time. The temp in our main living area where we spend most of our time is then 75, and at the far end of the house it is 73. The Master BR is 75 or 76. So nowhere is it actually 77. No, I have no real point, just an observation.