One Directions's 1D Day on Saturday was a massive success; the biggest YouTube music live stream ever.

It trended on Twitter at #1 Worldwide for 8 hours, with 9 million mentions of 1DDay and 1DDay Live, and 12 million mentions of all related hashtags in just 7 hours. 

One Direction's brand new album 'Midnight Memories' is out this week.

Watch the best of 1D Day before