The Honeywell RTH2300B thermostat is a "five-two day" programmable thermostat, meaning that it holds separate programs for weekdays and weekends. It can run both the heater and the air conditioner, and has four different time marks so you can program it to automatically adjust the temperature depending on the time of day. It comes preprogrammed with recommended EnergyStar settings, but you can adjust those to meet the individual needs of your home.
Press the "Set" button three times until "Set Schedule" shows up on the bottom of the display. You will see the word "Wake" on the display, as well as the days from Monday to Friday.
Adjust the time that you want to start this period. "Wake" periods are generally run in the morning, but you can set it for any time. Press the "Set" button.
Move the temperature switch on the bottom of the thermostat to the "Cool" position. Set the temperature for this period with the up and down arrows. Move the switch to "Heat" and set the temperature for that period. Press the "Set" button. You will see the days change to show only Saturday and Sunday.
Set the time and temperature for the "Wake" period on the weekends using the same process as you did for the weekdays. When you finish these settings, you will see the "Leave" period appear on the screen. Complete the process, both for weekdays and weekends, for the "Leave" period, followed by the "Return" period and the "Sleep" period. If you wish to skip a period, press and hold the "Hold" button for four seconds.
Press the "Run" button. Your program will now run as long as the temperature switch is in either the "Cool" or "Heat" position.
The "Wake" and "Return" periods are generally set with the most comfortable temperatures, since you will be moving about the house. "Leave" and "Sleep" are generally set with less comfortable temperatures, since you will either be gone or be sleeping.