FXX said in April that it will air the longest marathon in TV history when it welcomes The Simpsons repeats, and today the network announced that it’ll run August 21 through September 1. During the course of the mega-marathon, FXX will air in chronological order all 25 seasons — 552 episodes — of the Fox animated series that’s the longest-running scripted series in TV history. The Simpsons Movie will be included in the marathon and also will air chronologically within the stunt, after episode No. 400. The marathon begins at 10 AM ET/PT on August 21 and ends at midnight ET/PT on September 1.

Related: ‘The Simpsons’ To Debut On FXX With 552-Episode Marathon

FXX logoReminding TV critics about the stunt at the TCA Summer Press Tour, panelists also walked them through plans for a new interactive digital and online experience that’s billed as the ultimate Simpsons digital experience. Simpsons World — named after, and incorporating, Matt Groening’s published show bible of same name — offers a premium Simpsons fan experience, including access to their entire catalog of full-length episodes for the first time ever via FXNOW App and SimpsonsWorld.com, in October.

Related: TCA: FX’s John Landgraf Talks ‘AHS: Freak Show’ & ‘Fargo’, Freshman Renewals, W. Kamau Bell

Beginning September 2, FXX will regularly schedule The Simpsons episodes in fringe, primetime and late-night dayparts on weekdays and weekends. Additionally, every Sunday the network will broadcast a thematic mini-marathon consisting of eight Simpsons episodes beginning at 4 PM ET/PT and leading into the 8 PM ET/PT broadcast on Fox.

FXX will telecast four thematic marathons per year — the first being a 12-hour Halloween-themed marathon airing Sunday, October 26, when The Simpsons will not air on Fox broadcast network because of World Series coverage.

Related: Chase Carey Says ‘The Simpsons’ Opens Digital Opportunities For FXX

Simpsons World will give authenticated viewers instant and on-demand access to every single Simpsons via SimpsonsWorld.com, and FXNOW apps for iPhone, iPad, Xbox One, Xbox 360, Android phones and tablets, Smart TVs, and additional set-tops devices. Among the exclusive offerings, viewers will be able to explore Springfield’s characters and locations, the ability for users to curate their own personalized playlists and share their favorite show clips and quotes.

“It tracks American history,” FX Networks and FX Productions CEO John Landgraf said this morning of Simpsons World. “Anything that happened on any given day you can find a quote on it.” For a generation of viewers, he said, “The show has something funny to say about everything. People want to find those quotes and shat them. … It’s a place for the consumer to go get it and share it.”

Related: FXX Lands ‘The Simpsons’ In Biggest Off-Network Deal In TV History

Al JeanThe Simpsons exec producer Al Jean, came to the tour to tout the FXX package. ” I love The Simpsons.  I’ve worked there 25 years. It’s more than job — it’s part of my life,” he said, adding that he was “thrilled” cable and non-linear rights had gone to FXX “because of everything they’re going to do with it. … What I’m most excited about is the Simpsons World app. … I don’t want to oversee it, but I think this site is going to provide you with affordable health care… I could not be more thrilled.”

Simpsons World does not include The Simpsons footage from its time as an interstitial of The Tracey Ullman Show. But “we are very much working on that now,” FX Networks COO Chuck Saftler said, explaining that Groening controls those rights and their talks are “going in a positive direction.”

FXX announced in November that it had landed exclusive cable and VOD/nonlinear rights to The Simpsons, in what was reported to be the priciest off-network pact ever. The enormous size of the deal — which some sources said could each $1 billion if the series keeps producing new seasons — stems from the volume of Simpsons episodes available, which is scheduled to grow to 574 by September 2015.

Insiders estimate FXX would be paying about $1.25 million per week, with the length of the agreement said to be at least eight years. The granting of full VOD/non-linear rights to the cable network in conjunction with an off-network agreement, was a headline in itself when the deal was announced. FXNOW, the mobile viewing app of FX Networks, will offer all seasons of The Simpsons that are available on FXX.  The 21st Century Fox COO Chase Carey suggested years ago the company could launch a Simpsons cable channel. The Simpsons had been kept away from cable all these years; when it was sold in broadcast syndication in 1993, it was rare for a broadcast animated series — a genre of which TV stations were not too fond — cable TV was in its infancy, and Fox stations secured exclusivity for as long as the show was still airing on Fox, which we’re guessing no one had imagined back then would be 26 years and counting. The Simpsons’ only presence on cable until now had been via 2007’s The Simpsons Movie, to which FX has had the rights.