Ah They signed up for the Colorado AC rewards program, which apparently allows them to do that. We have something similar here in Florida.
FPL says that:
When you enroll your qualifying central electric air conditioner (A/C) and central electric heater, we can turn off your A/C for up to three hours per day in the summer (April – October) and your heater for up to three hours per day in the winter (November – March). and if you wish
With optional appliances, you can save even more! You can also enroll your conventional electric water heater and single-speed pool pump that can be switched off for up to four hours per day.
Sweet. ( sarcasm)