2PM member Taecyeon hinted at a comeback on his twitter. 

Taecyeon wrote on his twitter, "They say it won't work because the song title is too long... "You Know What Time It Is" is definitely a lot to pronounce and too long, right? T.T Hmm... So what should I name it? lol"

This hinted at the fact that Taecyeon was composing a song for 2PM's comeback set for the end of this year.