But the two stars won't be counting down alone. Mac Miller, J. Cole and Jason Derulo are all scheduled to appear on 'NYE in NYC 2012,' along with co-host and 'Teen Wolf' star Tyler Posey, who will be sharing MC duties with Demi.
While Selena is celebrating with MTV, her beau, Justin Bieber, will also be in Times Square, performing on 'Dick Clark's New Year's Rockin' Eve With Ryan Seacrest 2012.' Fans of Jelena may have a hard time deciding which program to watch.
If you decide to go with Demi and Selena, check out 'NYE in NYC 2012' live on MTV at 11PM ET on December 31. Who are you most excited to see on New Year's Eve?