The classic CBS children’s series Pee-Wee’s Playhouse gets an all-day marathon, running old episodes nonstop until 6 a.m. ET Friday. Oh, but there is one interruption, and it’s a welcome one: At 12:06 p.m. ET today, and again at 6:12 p.m. ET tonight, IFC presents the most recent revival special, Pee-Wee’s Christmas.