The boyband will take part in a live broadcast to be streamed on YouTube and Google+ between 7pm and 2am (2pm ET/11am PT) in support of their new album Midnight Memories, which is officially released on Monday, November 25.
Harry Styles, Liam Payne, Zayn Malik, Niall Horan and Louis Tomlinson will stream live to 61 countries from a studio in Los Angeles.
"1D Day is all about giving back to our amazing fans for supporting us for the past three years," Horan said. "When we suggested it, we never thought anyone would let us loose LIVE all day - we cannot wait!"
Celebrities including Piers Morgan, Kelly Rowland, Robbie Williams, Celine Dion, Simon Cowell, the Muppets and Khloe Kardashian will feature in the live stream, which will also see several performances from One Direction.
Everyone keeps askin what's gona happen on 1d day! Your gona have to wait and see !
— Niall Horan (@NiallOfficial) November 23, 2013
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There will be a "One Big Drop In" throughout the event - during which the group will crash 1D Google hangout parties across the world - as well as behind-the-scenes footage and world record attempts.
This sofa looks comfy (probably a good job as they're going to be there for SEVEN hours) 1DHQ x #1DDay pic.twitter.com/o08Q0rIkG4
— One Direction (@onedirection) November 23, 2013
"We've got celebrity guests coming in, we've got a quiz that we are doing, there's competitions..." 1D producer Ben Winston told MTV. "It's a really fun-packed day from everything from wrestlers to choirs to a house band to playing the new album. It's going to be packed."
Watch One Direction perform 'Story of My Life' on The X Factor USA below:
