The GOP frontrunner -- and frequent late-night punchline -- will be on Colbert's "Late Show" on Tuesday, September 22, CBS announced on Thursday.

Trump will appear on the same day as Dr. Ernest Moniz, the Obama administration's energy secretary. Perhaps Trump and Moniz will have an on-air debate about the Iran deal.

CBS announced Trump's appearance one day before the candidate visits Colbert's chief late-night rival, Jimmy Fallon of NBC's "Tonight Show."

Related: the 2016 race for late-night laughs

When Trump agreed to come on Fallon's show during Colbert's premiere week, it was interpreted as a snub of Colbert, who formerly played a conservative blowhard pundit on Comedy Central.