In USA off peak hours are cheaper then peak hours for electricity so for a friend I built a thermostat that keeps his shed a few degrees above freezing like 38 F during peak hours and during off peak hours he can set the degrees to whatever he wants using a pot and ds1307 and using a 5 volt dc to 200 volt ac solid state relay to run a 300 watt heater. Plus it has a switch to ignore peak hours if they want the room to stay always at a set degree. Im not looking for any prize just seen to add your project here button.
I only have a simple schematic. Maybe sometime i will get some pictures .