Title: List of Avatar: The Last Airbender episodes
Content:  Avatar: The Last Airbender is an American animated television series created by Michael Dante DiMartino and Bryan Konietzko. It first aired on February 21, 2005, on Nickelodeon with a one-hour series premiere and concluded its run with a two-hour TV movie on July 19, 2008. The Avatar: The Last Airbender franchise refers to each season as a "Book", in which each episode is referred to as a "chapter". Each "Book" takes its name from one of the elements that Aang, the protagonist, must master: Water, Earth, and Fire. The show's first two seasons each consisted of 20 episodes, while the third season had 21. In 
Title: Avatar: The Last Airbender (season 1)
Content:  The Last Airbender is a live-action film based on the first season of the animated television series and had a theatrical release on July 1, 2010. The film was directed by M. Night Shyamalan.
Title: Avatar: The Last Airbender (season 1)
Content:  Book One: Water is the first season of Avatar: The Last Airbender, an American animated television series produced by Nickelodeon Animation Studio. Created by Michael Dante DiMartino and Bryan Konietzko, the first season premiered on Nickelodeon on February 21, 2005. It consisted of 20 episodes and concluded on December 2, 2005. The series starred Zach Tyler Eisen, Mae Whitman, Jack DeSena, Dante Basco, Dee Bradley Baker, Mako Iwamatsu, and Jason Isaacs as the main character voices. The season revolves around the protagonist Aang and his friends Katara and Sokka going on a journey to the North Pole to find a Waterbending master to teach Aang and Katara. The 
Title: Avatar: The Last Airbender (upcoming TV series)
Content:  Avatar: The Last Airbender is an upcoming American adventure fantasy streaming television series. It is a live-action adaptation of the 2005 animated series of the same name. It was first announced in September 2018. Albert Kim is set to be the showrunner, with an ensemble cast including Gordon Cormier, Kiawentiio Tarbell, Ian Ousley, Dallas Liu, Paul Sun-Hyung Lee, and Daniel Dae Kim. The series is set to premiere on Netflix.
Title: Avatar: The Last Airbender
Content:  A video-game trilogy based on the series has been released. The Avatar: The Last Airbender video game was released on October 10, 2006, and Avatar: The Last Airbender – The Burning Earth was released on October 16, 2007. Avatar: The Last Airbender – Into the Inferno was released on October 13, 2008. Avatar: Legends of the Arena, a massively multiplayer online role-playing game (MMORPG) for Microsoft Windows, was released on September 15, 2008, by Nickelodeon. Players can create their own character and interact with other players around the world. Avatar: The Last Airbender was THQ's bestselling Nickelodeon game in 2006 and was one of Sony CEA's Greatest Hits. Aang and Zuko appear as skins for Merlin and Susano, respectively, in Smite. Avatar: The Last Airbender characters and locations are featured in Nickelodeon Kart Racers 2: Grand Prix.
Title: Avatar: The Last Airbender
Content:  The series consists of sixty-one episodes. The first episode—an-hour-long premiere—aired on February 21, 2005, on Nickelodeon. The series concluded with a two-hour television movie broadcast on July 19, 2008. Each season of the series is known as a "book", in which each episode is referred to as a "chapter". Each book takes its name from one of the elements Aang must master: Water, Earth, and Fire. The show's first two seasons each consists of twenty episodes and the third season has twenty-one. The entire series has been released on DVD in regions 1, 2 and 4. the complete series is 
Title: Avatar: The Last Airbender
Content:  Avatar: The Last Airbender, also known as Avatar: The Legend of Aang in some regions, is an American animated television series produced by Nickelodeon Animation Studios. It was co-created by Michael Dante DiMartino and Bryan Konietzko, with Aaron Ehasz serving as head writer. It aired on Nickelodeon for three seasons, from February 2005 to July 2008. Avatar is set in an Asiatic-inspired world in which certain people can telekinetically manipulate one of the four classical elements—water, earth, fire, or air—through practices known as "bending", inspired by Chinese martial arts. The only individual who can bend all four elements, the "Avatar", 
Title: Avatar: The Last Airbender (franchise)
Content:  Avatar franchise is an American multimedia franchise consisting of two animated television series, a live-action film, comics, books, video games, home media, and soundtracks. The franchise began with the animated television series Avatar: The Last Airbender, which aired on Nickelodeon from 2005 to 2008. The series is set in an Asian-inspired fantasy world in which some people can telekinetically manipulate (or "bend") one of the four classical elements: air, water, earth or fire. Only the titular "Avatar" can bend all four elements and is responsible for maintaining balance in the world. Since its original release, Avatar has developed into a franchise spanning works in various media. A sequel animated television series, The Legend of Korra, aired on Nickelodeon from 2012 to 2014 and has since expanded into its own sub-franchise. The storylines of both animated series have been 
Title: The Last Airbender (2010 film)
Content:  To avoid confusion with James Cameron's Avatar, the title was changed from Avatar: The Last Airbender to simply The Last Airbender. The film premiered in New York City on June 30, 2010, and opened the following day in 3,169 theaters, against The Twilight Saga: Eclipse which also stars Jackson Rathbone.
Title: Avatar: The Last Airbender (franchise)
Content:  The Last Airbender is a 2010 live-action adaptation of the first season of the animated series Avatar: The Last Airbender by M. Night Shyamalan. The film was widely panned by critics, as it has been considered one of the worst films ever made and took in $319 million at the worldwide box office.

Question: when did avatar the last airbender first air?
Answer: February 2005.
February 21, 2005.
February 21, 2005.