One Direction have been taking their boy band antics across the States since May for their first-ever American headlining tour. And, with only days left on the massive Up All Night jaunt, 1D-er Niall Horan, recalled with MTV News the "absolutely nuts" time they've had.

"It's been, as you can see clearly, it's been absolutely nuts. We're still trying to get out head around it," he said, hours before hitting the stage in Charlotte. "It's been crazy. We've had a lot of fun ... we're doing these things called sheds, so they're outside and inside. There are like 20,000 people on an outdoor gig and they're really good to do. They're really fun. It's really warm outside and the crowds, they're amazing."