First Lady Michelle Obama is keeping up a busy TV schedule Wednesday, including a visit to "The Late Show With David Letterman" that will air at night. From the White House: 

First Lady Michelle Obama will make three television appearances as part of a back to school tour to discuss improvements to the federal guidelines for school lunches that go into effect this school year, and updates to the Presidential Youth Fitness Program. Mrs. Obama will make her first visits to “The Dr. Oz Show” and “Rachael Ray” for appearances that will air in September. The First Lady will make her third appearance on the “Late Show with David Letterman,” which will air in the evening at 11:35 PM Eastern.