I don't know if it's that way, still, but when I was growing up down South, MG came on Friday nights. The last time I know it was on Friday nights was in 1998, but it probably still does air at that time in some places.
Buchannan recently said in an interview "we're on every Sunday", so I'm assuming its universal across the country. But check your old zip code:
http://www.mclaughlin.com/stations/state_search.asp