As an amateur/hobbyist horologist (clock/watchmaker) this is a question I get asked a lot. Can you turn your clock or watch backwards? Well, here’s my most recent FB post that I hope will answer your question. I’m always happy to share my knowledge with everyone.
A question I often get from people regarding fallback is whether or not you should turn a clock’s hands backwards. There’s a myth out there that you absolutely cannot turn a clock’s hands backwards. This is false.
When it comes to time-only clocks (including watches), or quartz clocks, there is no risk turning the hands backwards, regardless of what era it was made. There’s nothing to get out of sync anywhere.
On modern chiming/striking clocks (for example Howard Miller, Seth Thomas, Hermle, Kieninger, Ridgeway, etc.) it is perfectly safe to turn the minute hand backwards. These movements have a “slipping clutch” system in them that allows you to do so without damage to the movement. In addition, modern chiming clocks have a “self-righting” mechanism that will synchronize the chime/strike back to where it needs to be, though the chiming may seem to be out-of-sync for an hour or two.
For antique chiming/striking clocks, turning the hands backward is a big no-no. Either advance the minute hand 11 hours or stop the pendulum/escape wheel for an hour and let the time catch up.
Whatever the case, only move the minute hand. Moving the hour hand will result in the clock striking the incorrect hour as the hour hand will not be in sync with either the count wheel or the rack-and-snail (these systems are how the clock “knows” what time it is).
Anyway, hope that educated someone.