TV highlights: SNL looks back at its past on the live three-hour 'Saturday Night Live 40th Anniversary Special'

(All times Eastern.)The Lifetime Original Movie "Back to School Mom" (Lifetime at 8 p.m.) stars Kimberly Elise as a 41-year-old woman who has decided to return to college and finish her degree. Because no L.O.M. can get away with being that lighthearted, beware the devastating twist.