I have the same thing right now, runs for an extra second after turning it off and clock keeps resetting except mine doesn't always go to 12:00. Haven't looked into it yet but it is definitely annoying.
It fixed itself today. Through about 4 ignition on/off cycles, the clock has returned to the correct time. I didn't do anything to make this happen; no battery disconnect or anything else that might be related.
This may seem weird, but, the clock is told the time from the WCM (the module that handles the anti theft key ).Chrysler doesn't tell me which model this stands true for.
It is common for us to see clock issues, and I am told there is no rhyme or reason for it, at one time, mine would drop 4 hours while driving down the road.
First thing I would check is power to the radio though and be sure your not losing the keep alive memory power as this affects it too