The seven-hour live stream goes down November 23, featuring not only the fivesome but also celebrity guests and special content created just for the show. Fans can also get in on the action by suggesting show ideas and sending in videos. The live show portion will be taped from a still-unconfirmed TV studio.
"A few months ago we decided that we wanted to give back something to all the fans who supported us," Harry Styles said in a video announcement about the November 23 event with his bandmates by his side.
"We had such an amazing three years and we couldn't have done it without you guys," Liam Payne continued. "So we put all our heads together and came up with the idea of 1D Day."
The event comes right after the guys wrap up their Take Me Home Tour in November in Tokyo, and before they hit the road yet again for their worldwide Where We Are Tour, which kicks off in April.
And with Midnight Memories just around the corner, we caught up with One Direction producer Julian Bunetta to get details on their new music.
"I think [the lead single 'Best Song Ever'] is a perfect bridge between what they've done and where they want to go. They're a little more grown up," he said. "I think it's a good transition into the rest of the album; it's going to be an incredible, incredible album. I'm really proud of the stuff we've done."