What is the difference between the WAKE and RETURN time periods?

WAKE is the time period when you want the house at a comfortable temperature when you get up and prepare for work or school, with extra lead time for the furnace to heat the house before you wake. RETURN is the time period when you want the house at a comfortable temperature for activities before bedtime, also with extra lead time before you arrive home. Both should include lead time based on outside temperature and furnace response time.