American Idol host Ryan Seacrest started the celebrity countdown campaign.
"Alright here we go. Good news. Big news. In 30 days the single called What Do You Mean? is coming out. So, start the countdown clocks," Seacrest said in a video on Twitter.
Next up was Aussie actor and Bieber look-alike, Ruby Rose. She sat in a gondola with a sign that read "29 days" and posted the snap to Bieber's Twitter and Instagram accounts.
Other celebs who have helped out the 21-year-old popstar include Mariah Carey, Kylie Jenner, Halsey and The Fat Jewish.
Singer Ariana Grande, who's shared a stage with Bieber, is one of the select few who've heard the song.
"Yes, I've heard it... yes, it's fantastic," she said on Twitter.
The rest of the world will have to wait until August 28.
- WENN
