Billie Piper (in-universe)

According to radio newscaster Rosemary Stark, Billie was a British singer and actress whose birthday fell on 22 September. Tegan Jovanka turned off the radio. (AUDIO: The Gathering)

Behind the scenes
Billie Piper played companion Rose Tyler, and was in fact born on 22 September 1982.

Billie Piper's first album, (1998), was seen in Gwen Cooper and Rhys Williams' flat in the Torchwood episode Something Borrowed.