Hello all, This is my first post so go easy on me! I recently graduated from college with a mechanical engineering degree. For my senior design project I was tasked with designing and building an all-mechanical clock capable of displaying the time and date (while accounting for leap year) which would only require a rewinding once a year at most. As I'm sure you can guess, the project was a total failure! I was unable to come up with an appropriate design which accounted for a leap year or find any reference to an existing calendar clock that can run as long as I wanted. I am aware there are existing anniversary (400 day) clocks with run about a year by utilizing a torsional pendulum and Atmos clocks which run "automatically" via a gas bellows design. Is anyone here aware of any calendar clock that can run for this long? Is it even possible? I figured the best place to start would be to buy a Seth Thomas or Ithaca Calendar Company clock and attempt to replicate or re-engineer it. I've done a lot of research over the past year and a half or so but haven't had much luck. Considering that I'm now done with school this project isn't a necessity and I tried to just drop it but my dumb brain won't let me forget about it! Any suggestions you guys have would be much appreciated! Thanks!