This was just announced by an administrator at the GSN forums.
On the 4th, there will be a Hollywood Squares Mini-Marathon from 9 PM-12 AM Eastern with episodes featuring Mr. Hackett.
Then later, there's going to be a special Black & White Overnight tribute with these shows:
4:00 AM Password
Celebrities: B. Hackett, B. Palmer
4:30 AM What's My Line? (10/24/65)
Buddy is on the panel. Guests include Danny Kaye, Bette Davis, and Yves Saint Laurent.
5:00 AM I've Got a Secret (3/1/65)
Buddy is on the panel. Guests are Bette Davis & Olivia de Havilland. Johnny Olson appears on camera in an audience spot.
5:30 AM To Tell the Truth