Quote Originally Posted by Omen87 View Post
I don't think you will ever see a fix to the calendar issue. If I'm not mistaken, the DIC uses the clock in the factory stereo to keep time for the calendar.
Hate to bring up an old thread but hopefully it will help someone. I had the same problem a couple months ago when I installed my nav unit (date/time gone). Didn't bother me too much since I had heard that had happened to a few. But then last week I did an oil change for the first time since I installed the nav unit and I was unable to reset my oil life monitor. It monitored the life just fine, but the reset button did nothing. I changed the oil at about 30% so I had to do something before it started chiming at me to change my oil. I researched and it turns out I was given the wrong chime retention unit. I was given a GMRC-01 but what was supposed to get the GMOS-04. I believe this will fix the date/time issue as well. It just arrived yesterday and I plan on installing it this afternoon. I'll post back with if it works.