Our long national nightmare is over: David Letterman is returning to work after a monthlong sick leave. The ''Late Show'' host will be back at his desk Monday night and for the rest of the week, CBS announced over the weekend. The return marks Dave's apparent recovery from his painful bout of shingles and the end of only his second sick leave in 21 years (the first, his similarly lengthy absence after heart surgery, took place in 2000).
Letterman hasn't been on the air since Feb. 25, when he complained on stage of eye pains that turned out to be the viral infection shingles. Since then, thanks to previously scheduled reruns and NCAA basketball finals, he missed only 14 shows, replaced each night by guest hosts ranging from seasoned talkmeisters (Regis Philbin, Whoopi Goldberg) to credible rookies (Vince Vaughn, Elvis Costello). On his first night back, Dave's guests are scheduled to include Billy Crystal and 18-year-old whistling champion Michael Barimo.