They might be the world’s biggest boyband with five unique personalities and equally amazing hair – but a seven hour live solo show is a big ask.

So it’s not at all surprising One Direction have called upon a few favours from their showbiz pals to help fill time in their mind-blowing 1D Day.

The LIVE broadcast of the band takes place on Saturday [Nov 23] between 7pm – 2am for fans in the UK.

And if fans weren’t already crossing their legs in excitement Harry, Niall, Zayn, Liam and Louis will be joined by some of the biggest stars.

In a teaser video posted on their official YouTube account, it’s reveals special guests including Robbie Williams, Celine Dion, Simon Cowell, Piers Morgan, The Muppets and many more.

1D Day will be broadcast on YouTube & Google+ and will include behind the scenes footage, exclusive plays of tracks from their new album Midnight Memories and, er, Guinness World record attempts.

Video Loading Video Unavailable Click to play Tap to play The video will start in 8 Cancel Play now

As a little extra treat, the seven-hour bonanza will also broadcast live into Doctor Who Live: The Afterparty on BBC3.

The show will feature a host of previous Doctors and their time-travelling companions which is all a bit exciting, isn’t it?

Any die-hard fans who have taken part in the tedious 1D Day challenges over the past few weeks will have the luxury chance to spot their work on screen. Exactly, no expenses spared.

But the ultimate prize will be for a lucky bunch of Directioners around the world who’ll get the opportunity to hangout with the guys and participate live in the stream.

The band will be surprising fans by dropping into their Google+ Hangout parties and chatting live face-to-face in a special feature called One Big Drop In.

It’s just a shame that nobody really uses Google+…

And the all important links are: www.google.com/+onedirection, www.youtube.com/onedirection

Video Loading Video Unavailable Click to play Tap to play The video will start in 8 Cancel Play now

Are you the biggest 1D fan? Test your knowledge here.

You can buy your tickets to One Direction 2014 stadium tour We Are Here - right here = with Mirror Tickets, just click on a date below: