Question: When did the season of "The Simpsons", that contains the episode "Barthood", begin airing in the United States?

Context articles: Southland (TV series)
Barthood
Scandal (season 7)
The Simpsons (season 27)
Clown in the Dumps
In the Name of the Grandfather
Mr. Osomatsu
List of Southland episodes
The Simpsons 138th Episode Spectacular
Lisa the Drama Queen

Southland (stylized as SOUTHND) is an American television crime drama series created by writer Ann Biderman and produced by Warner Bros.
 Television.
 It originally aired on NBC for one season from April 9 to May 21, 2009, and then on TNT for four additional seasons from March 2, 2010, to April 17, 2013.
 On May 1, 2009, NBC announced that "Southland" had been renewed for a second season with an initial 13-episode order to begin airing on Friday, September 25, 2009, at 9:00 pm, one hour earlier than its original time slot.
 On August 27, 2009, shortly before its scheduled premiere, NBC moved the opening of its second season to October 23, 2009, citing the need to promote the show more fully.
 On October 8, 2009, NBC announced that the series had been canceled after one season.
"Barthood" is the ninth episode of the twenty-seventh season of the animated television series "The Simpsons", and the 583rd episode of the series overall.
 It aired in the United States on Fox on December 13, 2015.
 The episode parodies the 2014 film "Boyhood" and marks the final episode to credit Sam Simon as executive producer.
The seventh and final season of the American television drama series "Scandal" was ordered on February 10, 2017 by ABC.
 It was later announced that the seventh season will be the final season for "Scandal".
 The season will begin airing on October 5, 2017, and will consist of 18 episodes, adding the total episode count of the show to 124 episodes.
 Cast member George Newbern was upgraded to a series regular after being a recurring cast member for the past six seasons.
 The season will be produced by ABC Studios, in association with ShondaLand Production Company; the showrunner being Shonda Rhimes.
"The Simpsons"' twenty-seventh season began airing on Fox in the United States on September 27, 2015, and ended on May 22, 2016.
 On October 28, 2014, executive producer Al Jean announced that Season 27 went into production, renewing the series through the 2015–16 season.
"Clown in the Dumps" is the season premiere of the twenty-sixth season of the American animated television series "The Simpsons", and the 553rd episode of the series overall.
 It first aired in the United States on the Fox network on September 28, 2014, with "The Simpsons Guy", a crossover episode of "Family Guy" with "The Simpsons", airing afterwards.
 This episode was dedicated in memory of Louis Castellaneta, the father of "The Simpsons" voice actor Dan Castellaneta.
 It was written by Joel H. Cohen and directed by Steven Dean Moore, with Don Hertzfeldt directing a sequence in the opening titles.
 Jeff Ross, Sarah Silverman and David Hyde Pierce guest starred as themselves, with Jackie Mason and Kelsey Grammer reprising their respective roles as Rabbi Krustofski and Sideshow Bob, while Maurice LaMarche voiced several minor characters.
"In the Name of the Grandfather" is the fourteenth episode of the twentieth season of "The Simpsons".
 It first aired on Sky1 on St. Patrick's Day, March 17, 2009 and aired on the Fox network in the United States on March 22, 2009.
 It was the first episode of the show to premiere in Europe before airing on Fox.
 In the episode, the Simpsons buy a new hot tub and spend so much time relaxing in it that they neglect Abraham "Grampa" Simpson.
 Homer decides to make it up to Grampa by helping him do one thing he wants to do.
 Grampa reminisces about O'Flanagan's pub in Ireland where he once had the best night of his life so the Simpsons travel there.
 Marge, Bart and Lisa visit various Irish landmarks while Homer and Grampa buy O'Flanagan's during a night of binge drinking and soon discover that pubs are no longer popular in Ireland.
Mr. Osomatsu (Japanese: おそ松さん , Hepburn: Osomatsu-san ) is a 2015 comedy anime television series by Pierrot, based on Fujio Akatsuka's 1962 manga series, "Osomatsu-kun".
 Celebrating Akatsuka's eightieth birthday, the series follows the sextuplet Matsuno brothers from the original series as adults, and features more adult-oriented humor compared to the original series.
 The series aired in Japan between October 2015 and March 2016, with a special episode airing in December 2016.
 A second season will begin airing in October 2017.
 Both seasons have been licensed in North, Central and South America by Viz Media.
 A manga adaptation by Masako Shitaro began serialization in Shueisha's "You" magazine from January 2016.
"Southland" is an American television drama series created by Ann Biderman.
 It began airing on NBC on April 9, 2009.
 NBC announced that "Southland" had been renewed for a second season with an initial 13 episode order to begin airing on Friday, September 25, 2009, at 9:00 pm, one hour earlier than its original Thursday time slot.
 Shortly before its scheduled premiere, NBC moved the opening of its second season to October 23, 2009, citing the need to promote the show more fully.
 On October 8, 2009, NBC announced that the series had been canceled.
"The Simpsons 138th Episode Spectacular" is the tenth episode of "The Simpsons"<nowiki>'</nowiki> seventh season.
 It originally aired on the Fox network in the United States on December 3, 1995.
 As the title suggests, it is the 138th episode and the third clip show episode of "The Simpsons", after "" and "Another Simpsons Clip Show".
 While the "138th Episode Spectacular" compiles sequences from episodes throughout the entire series like the previous two, it also shows clips from the original Simpsons shorts from "The Tracey Ullman Show" and other previously unaired material.
 Like the Halloween specials, the episode is considered non-canon and falls outside of the show's regular continuity.
"Lisa the Drama Queen" is the ninth episode of the twentieth season of "The Simpsons".
 It originally aired on the Fox network in the United States on January 25, 2009 and guest starred Emily Blunt as Juliet.
 A special version of the end credits theme was performed by Fall Out Boy, although they do not guest star in the actual episode.
 This was the last episode in the series to be presented only in standard definition, the first regular episode to begin right after the opening credits without a commercial break, with an episode now having four segments, and the last episode to use the original opening sequence starting from Season 2.
 Brian Kelley returns as a writer after five seasons of being absent from the show.
 The episode is very loosely based on the 1994 film "Heavenly Creatures".