Well, PaulS, let me explain ...
I believe I am running it at the right voltage. I put in a 1.5V AA battery. Duracell, I think, if that makes a difference. The temperature is around 20 (celsius) although it tends to rise a bit in the afternoons. I haven't noticed any crystal or resonator.
Now, at 11 in the morning I put on a roast turkey, which I need to cook for two hours, so naturally I expect it to finish at 13 hours. But the clock only goes up to 12! So it never reaches 13, and the turkey is burnt to a crisp. I'm at my wits' end. So I'm pretty sure it is overflowing (is that the right word?).
I hit upon the idea of resetting the clock. That is, when I put the turkey in, I crank the hands back to zero. Now I don't know if you own a clock, but that isn't that easy to do, as there is no zero on the dial. So what I do is go to "1", and move the hands back to just before "12" and hope for the best.
That works well enough, but I do find that when I am cooking I lose track of time. It always seems to be between 12 and 2.
And the worst part is, if I want to cook potatoes for one hour (while the turkey is cooking) I have to find a second clock!
I hope you can advise me on how to do this in a simpler way.