How do use the timer on my boiler setback control?

The control is a Varistat R.D. 601 temperature proportional setback control, the clock is og. I talked to the manufacturer; they said this model is too old for them to support. The clock controls are not simple like those on an electric lighting timer. Also I would like your opinion on changing the other settings(ratio, etc.) from the defaults. The manufacturer did explain this to me, but I forgot the math. If you need it, I can send a digital image of the device.