Myson Marathon 500C?

I have just moved into a house and am having problems setting the timer on the boiler, it does not seem to actually work when you set it to turn the boiler on in the morning I have set the pins to when I want it to turn on , if there something else i have to do like set the time on the boiler? the dial does not seem to go around during the day? is it supposed to ?

Any help would be appriacated