Taylor Swift will be a guest on The Jay Leno Show on Friday (Dec. 4). The episode will air at 10 p.m. ET/PT on NBC. In addition, Swift will be a guest at the Jingle Ball concerts sponsored by KIIS-FM/Los Angeles and WHTZ-FM (Z100)/New York City. The first event takes place Saturday (Dec. 5) the Nokia Theatre in Los Angeles. The New York concert is scheduled for Dec. 11 at Madison Square Garden. In related news, the episode of Saturday Night Live featuring Swift as host and musical guest will re-air on Dec. 26 on NBC.