How to Adjust an Anniversary Clock. Anniversary clocks are very popular today for several reasons. One of which is that they require very little attending. Once set, wound and adjusted, an anniversary clock can keep accurate time for a year. If your anniversary clock is not keeping time accurately, they are relatively easy to adjust.
Wind the anniversary clock or insert batteries if it is battery operated. Set the correct time on the clock.
Monitor the clock for one week to see how accurately it is keeping time. Determine if your anniversary clock is running fast or slow.
Remove the glass or plastic dome from the top of the clock. Using your hand, gently grasp and hold the pendulum to stop it.
Hold the base of the pendulum and carefully rotate it a small amount, approximately 1/6th inch towards the markings on the clock that say "Slow" or "Retard," if the clock is running fast. Your clock could also be marked with an "S" or an "R" instead of spelling out the full word.
Rotate towards "Fast" or "Advance," in the same manner, if you clock is running slow. Again, your clock could simply be marked with an "F" or an "A". Be careful to only rotate it approximately 1/16th inch.
Place the dome back onto the clock and monitor it again for a few days to see if it is now keeping time accurately.
Adjust the clock another 1/16th inch in the necessary direction if it is still running fast or slow. It might take several adjustments before your anniversary clock is properly set; however, it is important to only adjust in small increments so as to not cause damage to the clock.