I have a 20 year. i have a 20 year old honeywell quartz air/heating control. I'm not really sure

Question

i have a 20 year old honeywell quartz air/heating control. I'm not really sure how to use the heater. It has two separate toggles at the top (one blue and one red), a button that you push "up" at the bottom, which appears to turn this dial inside to either red or blue, a clock thing that doesn't work, or at least appears to do nothing. The air comes out warm for a bit, and then goes cold.