Expert: William J Perkins - 11/24/2009

Question
I recently bought a Seth Thomas Grandfather clock at an estate sale. I have it set up and it seems to be running fine I still have a little adjusting to do on the time but other than that it's doing great.
My question is, There is a hole with what looks to be a screw in the face between the second dial and the month dial and I don't know what it is for. It has dials for seconds, months, days, and moon phases if that helps. I'm not sure of the age, the person selling it said it was from the late 70's early 80's
Thanks

Answer
Before responing I have to know some more about the movement.  Please gain access to the back of the movement.  Copy down and send me ALL the information stamped upon the movements brass backplate.  That data will most likely provide the information I need.  Regards WJP