I set mine up myself (easy setup was a perk I noticed when buying it a few years ago) and in the application, there are several details you want to fill out on

I set mine up myself (easy setup was a perk I noticed when buying it a few years ago) and in the application, there are several details you want to fill out on initial setup. A big one is the type of heating/cooling you have in your house because it adjusts behavior in response. Over time it "learns" the quirks of your setup such as how responsive it is and adjusts to compensate. At least that's how it's supposed to work and how mine works. The "90 minutes" or "2 hours" or whatever it shows is supposed to be based on its estimate based on how it's modeled your house's hvac setup.