xfinity marking shows as new but the dates go back years

In the guide, now well over 10 TV shows each and every night, xfinity is showing them as new, but they are in fact old.  The put the date on, but the date shows they were first broadcast years ago.  Some go back to even before 2010.  How can a show be new if it was broadcast that many years ago.  If you check the episode guide, it confirms the real date and usually has many seasons after the "new" show.  Why is xfinity having so many issues with the guide?