if wall clock has a pendulum at the bottom there is usually a screw thread adjustment that you TURN in small steps then time over say 12hrs to see weather it has done anything .
by screwing the ADJUSTMENT ANTI CLOCK WISE the clock SHOULD lose time
by screwing the ADJUSTMENT CLOCKWISE the clock SHOULD gain time
(if the clock is a quartz you have a bad crystal )
wirecutterman, September 2008
