Repair timer
You can still get repair parts for that controller. Could be the 24 hour clock motor. Could be a chipped gear or broke off lever. If you're handy you could take the panel off and see if you can figure it. Irrigation supply houses have the parts you need. Such as, Hydroscape, Ewing and John Deere. They could also recommend someone to repair the controller for you or they might be able to send the controller in for repairs.
Good luck.