The countdown is on for CBS’s “Late Show with David Letterman,” with the late-night institution’s final show set for May 20.

The network today announced a star-studded lineup of guests for Letterman’s final 28 shows, starting with tonight’s confirmed lineup of Sarah Jessica Parker, 2015 Masters champion Jordan Spieth and musical guests Asleep at the Wheel.

Tuesday’s show will feature Billy Crystal, “The Talk” co-host Julie Chen and country singer Chris Stapleton. The guests later in the week will be Michael J. Fox, Amy Sedaris and musical guests Iron & Wine and Ben Bridwell (April 15); Kevin James, comedian Tom Dreesen and musical guest Tracy Chapman (April 16); and Alec Baldwin and musical guest John Mayer (April 17).

Others coming up during the runup to the finale include George Clooney, Billy Crystal, Robert Downey Jr., Will Ferrell, Tina Fey, Tom Hanks, Scarlett Johansson, Michael Keaton, Steve Martin, Bill Murray, Don Rickles, Julia Roberts, Jerry Seinfeld, Martin Short, Howard Stern, John Travolta and Oprah Winfrey.

Please click here for the rest of the lineup in the announcement from CBS.