The date is a year longer than Fox's original estimates of 2014.
"We're not really naming dates, but I think 2014 will be a tough date for us to make," producer Jon Landau recently told Empire. "To us, it's about getting it right. [...] The first 'Avatar' was supposed to be 2008, it was 2009. Movies make release dates, release dates don't make movies."
James Cameron has also reportedly bought 2,500 acres of land in New Zealand, after he said the sequels will almost certainly be shot in the area.
The director recently revealed his plans to focus solely on the Avatar franchise.
"I'm in the Avatar business. Period," he said. "I'm making Avatar, Avatar 2, Avatar 3, maybe Avatar 4, and I'm not going to produce other people's movies for them."
He continued: "I'm not interested in taking scripts. And that all sounds a little bit restricted, but the point is I think within the Avatar landscape I can say everything I need to say that I think needs to be said, in terms of the state of the world and what I think we need to be doing about it. And doing it in an entertaining way."
Sigourney Weaver has been confirmed for all three films and recently revealed they will be filmed simultaneously.