The Simpsons/Treehouse of Horror XX

"Treehouse of Horror XX" is the fourth episode of the twenty-first season of The Simpsons and the twentieth installment in the series' annual "Treehouse of Horror" Halloween specials.
==Broadcast History==
===2009===
Air Date 	Time 	Notes
October 18, 2009	8:00pmThe Simpsons Archive	
===2010===
Air Date 	Time 	Notes
May 23, 2010 	7:30pm	
November 7, 2010	7:30pm	
===2013===
Air Date 	Time 	Notes
October 6, 2013	7:00pm	West coast-only airing.
==Footnotes==
Category:Guides