In 1979 we bought a very nice circular wall clock (with genuine pine surround) wot had "fallen off of the back of a lorry" from the geezer across the road. Cost us a fiver. It still looks as good as new, it neither gains nor loses a single second and I've changed the single AA battery just four times in all that time. Putting it forward or back an hour is a cinch: you just open the hinged glass door and there's a little brass knob right in the middle where the hands are fixed. They don't make 'em like that any more.