Event timing not working

About 6 months ago my events, set to sunset in one case and a set time in another started being several hours delayed. We have reprogrammed and tried using only set times but seems timing operation is off 2-21/2 hours. Tech has reset main unit as well. System is 13 years old-Radio Ra2

I would check to see if the location got changed somehow. You can also set timed events to occur up to 4 hours before or after sunset. Maybe it got changed?