Logo will kick things off by airing an all day marathon (A Buffyfest!) on New Year's Day, after which it will air 4 times daily at 6pm, 7pm, 2 am and 3 am in addition to extra weekend hours, starting January 4th.
I guess MTV has totally abandoned playing music altogether at this point, but bonus for us...at least in this respect. They also start with a Buffyfest at 11 am on Sunday, January 10th. Then it will air regularly on MTV at 11 am on weekdays. Check your local listings!