'I'm just going to relax,' singer says of his plans.By Jocelyn Vena Justin Bieber eating cheesecake Photo: Getty Images Justin Bieber turns 17 on March 1, and he's revealing what his plans are for the big day. "I only have, like, four days, so I'm just going to relax, because I start my world tour starting on [March 4] -- so just going to mentally prepare and just relax," Justin told "Entertainment Tonight." "No birthday bash.