Antique Clock Market

justinlimkt asked: I have a problem with my antique clock because it does not chime occasionally.
General rule: the clock chimes every half an hour.
there are two problems:
1. the clock skips the chime sometimes, leaving the chime numbers to be irregular
e.g:
at 4 it chimes 4 times
at 4.30 it chimes once (because it is 1/2 hour chime)
at [...]