Rihanna's Happy Birthday wish

Rihanna is one of the busiest girls in show biz!

She opened up the American Music Awards last night with a bang, and is also spending the week promoting her new album, Loud. But she’s also taking a little time out to say happy birthday.

The songstress is lending her time and talent to help the American Cancer Society, to help create a world with less cancer and More Birthdays. Her happy birthday video was inspired by the 11 million cancer survivors who will celebrate another birthday this year, and debuted last night during the AMA awards.

Rihanna explains what this movement means to her, “It means more hope, more love, more friends, more summers, more memories. More time you can enjoy and spend with your family and friends – the people that you love and the people that love you, because you deserve that.”

Rihanna joins Usher, Justin Bieber, and many other entertainers in supporting the cause.