Does anyone know of a smart thermostat that actually has this function? Every thermostat I've looked for has "heat mode" where it decides if it should be blasting heat or not, and "cool mode", where it decides it should be blasting the AC or not. I have not found the mythical smart thermostat that does the job of "keep the temperature around here" +/- a few degrees.

I live in an area where its cold at night and hot during the day and I am bad at remembering to change the thermostat from mode to mode and haven't found a programmable IOT thermostat I can write a script for, recommendations welcome!