Question: A Very Crappy Christmas was an episode in season four of South Park, which began airing on what date?
Context: "Previously Unaired Christmas" is the eighth episode and fall finale of the fifth season of the American musical television series "Glee", and the ninety-sixth episode overall.  It was directed by Wendey Stanzler and written by Ross Maxwell, and it aired on Fox in the United States on December 5, 2013.  The episode is the show's fourth Christmas special, but due to season five being set in the same calendar year as season four, it is a non-canonical episode which purports to be the original season four Christmas special, suppressed by Fox. "A Very Crappy Christmas" is the seventeenth and final episode of the fourth season of the animated television series "South Park", and the 65th episode overall.  It first aired on Comedy Central in the United States on December 20, 2000.  In the episode, Kyle awaits Mr. Hankey on Christmas, but he does not show up.  To try to spread some Christmas cheer, Kyle and the boys decide to create their own animated special. Season four of Cold Case, an American television series, began airing on September 24, 2006 and concluded on May 6, 2007.  Season four regular cast members include Kathryn Morris, Danny Pino, John Finn, Thom Barry, Jeremy Ratchford and Tracie Thoms.  This is the only season of the series to feature 24 episodes. Season four of "Stargate SG-1", an American-Canadian television series, began airing on June 30, 2000 on Showtime.  The fourth season concluded after 22 episodes on February 14, 2001 on British Sky One, which overtook Showtime in mid-season.  The series was developed by Brad Wright and Jonathan Glassner.  Season four regular cast members include Richard Dean Anderson, Michael Shanks, Amanda Tapping, Christopher Judge, and Don S. Davis. The fourth season of the television drama series "Winners & Losers" will air in two parts on the Seven Network in Australia.  Season 4A – comprising 13 episodes – began airing on 1 July 2014 and concluded airing on 23 September 2014, while Season 4B – comprising 13 episodes – began airing on 14 July 2015.  Season four began immediately after the conclusion of the third season.  Season four follows the lives of Jenny, Bec, Sophie, Frances and Sam two months on from the discovery that Frances is pregnant.  Filming for the season began in February 2014 and wrapped in November 2014. "Total Drama" is a Canadian animated comedy television series that began airing on Teletoon in 2007.  The first season, titled "Total Drama Island", follows twenty-two contestants on a reality show of the same name.  A second season, titled "Total Drama Action", began airing in January 2009, this time following fourteen (later fifteen) returning contestants.  The third season, "Total Drama World Tour", began in June 2010, and followed fifteen returning contestants along with two (later three) new contestants.  The show's fourth season, "", began airing in 2012, and was the first season to feature an entirely new set of contestants.  The fifth season began airing in 2014, and was split into two parts, "Total Drama All-Stars" and "Total Drama: Pahkitew Island".  The first part featured contestants from the first four seasons, while the second part introduced new contestants.  The show was recently picked up for a sixth season. Season two of "South Park", an American animated television series created by Trey Parker and Matt Stone, began airing on April 1, 1998.  The second season concluded after 18 episodes on January 20, 1999; it remains the longest season of "South Park" to date.  While most of the episodes were directed by series creator Trey Parker, Season 2 includes two episodes directed by Eric Stough. The fifteenth season of the American animated sitcom "South Park" began airing on Comedy Central on April 27, 2011 and ended on November 16, 2011.  In response to reactions to the mid-season finale episode "You're Getting Old", which seemed to insinuate that creators Trey Parker and Matt Stone were wrapping up the series, Comedy Central proclaimed through the media that "South Park" was renewed for two more seasons, and the duo were signed through 2013.  Shortly before the airing of the season finale episode "The Poor Kid", "South Park" was extended again until 2016, taking the show to 20 seasons.  Parker was the director and writer for all episodes, and Robert Lopez was the writer in this eleventh episode for the fifteenth season. Season four of "Smallville", an American television series, began airing on September 22, 2004.  The series recounts the early adventures of Kryptonian Clark Kent as he adjusts to life in the fictional town of Smallville, Kansas, during the years before he becomes Superman.  The fourth season comprises 22 episodes and concluded its initial airing on May 18, 2005.  Regular cast members during season four include Tom Welling, Kristin Kreuk, Michael Rosenbaum, Jensen Ackles, Allison Mack, John Glover, Annette O'Toole and John Schneider. Season four of "South Park", an American animated television series created by Trey Parker and Matt Stone, began airing on April 5, 2000.  The fourth season concluded after 17 episodes on December 20, 2000.
Answer: April 5, 2000