HI--my name is XXXXX XXXXX X can assist you. The timekeeping ability of a clock is tied closely to the clock's environment, that is, temperature and humidity variations can cause time fluctuations. Time errors can be induced by vibrations such as slammed doors or, for example, dresser drawers being opened and closed, if the clock is located on a dresser. For most models of clocks, turning the indicator to the left will be slower and to the right, faster.
Most mantle clocks have the adjustment mechanism on the face of the clock as a wheel or arbor (usually at the top or near the center) with F (fast) or S (slow) clearly marked. If the clock is running fast each day, turn the arbor or wheel toward the S to slow it down. This usually takes less than a half of a turn of the wheel or arbor.
It is important that you reset the clock to the correct time and be sure the clock is fully wound and level, then monitor how much time your clock is losing or gaining after your adjustment (and then readjust the arbor/wheel left or right to further fine tune the clock).
If the S-F adjustment fails, you likely have a worn bushing which will need to be repaired or replaced.