Dashboard clock running 30 mins faster overnight

[Roger Diver 0]

My 2013 GS350's dashboard clock has started to run 30+  mins faster.  I can fix the time in the evening and the following morning is 30+ mins faster..  This has been going on for 4 days now.  Clock was accurate before that time.  Weather has been reasonable (30-60F) so no extreme temperatures to affect voltage.  Battery is about 4yrs old.  I don't have a problem cranking up in the morning.

Any thoughts?