Thursday, December 20, 2012 ratings — New Episodes: Rock Center With Brian Williams and the season finale of The X Factor. Specials: I Want a Dog for Christmas, Charlie Brown (repeat), CMA Country Christmas, and A White House Christmas: First Families Remember. Episode Reruns: The Big Bang Theory, Two And A Half Men, Person Of Interest, Elementary, The Vampire Diaries, Beauty And The Beast, Parks And Recreation, and The Office.

Below are the fast affiliate ratings. The “demo” refers to the viewers in the 18-49 demographic. The percentages represent the change since the previous original episode. (Percentages aren’t given for reruns or specials.) “Millions” refers to the total number of viewers.

To see past ratings for a particular show, click the show’s link. The show pages are updated with the daily final ratings when they become available. Those pages include percentage changes in both the demo and total viewership, in addition to season averages to date.

ABC
8pm – I Want a Dog for Christmas, Charlie Brown: (repeat, special) 1.4 in the demo with 5.1 million.
9pm – CMA Country Christmas: (special) 1.5 in the demo with 7.3 million.

CBS
8pm – The Big Bang Theory: (repeat) 2.8 in the demo with 10.9 million.
8:30pm – Two and a Half Men: (repeat) 2.3 in the demo with 8.7 million.
9pm – Person of Interest: (repeat) 1.7 in the demo with 9.4 million.
10pm – Elementary: (repeat) 1.3 in the demo with 6.8 million.

The CW:
8pm – The Vampire Diaries: (repeat) 0.3 in the demo with 0.98 million.
9pm – Beauty and the Beast: (repeat) 0.3 in the demo with 0.9 million.

FOX
8pm – The X Factor: 3.1 in the demo (+29% change) with 9.6 million.

NBC
8pm – A White House Christmas: First Families Remember: 1.6 in the demo with 8.5 million.
9pm – The Office: (repeat) 1.0 in the demo with 3.1 million.
9:30pm – Parks and Recreation: (repeat) 0.8 in the demo with 2.1 million.
10pm – Rock Center with Brian Williams: 0.8 in the demo (-11% change) with 3.5 million.

What were you watching last night? The X Factor season finale or something else?