 " The <unk> " aired on BBC One on 25 December 2012 at 5 : 15 pm , the same day on BBC America in the US and Space in Canada and the next day on <unk> in Australia and on Prime in New Zealand . UK overnight ratings showed that the special had been watched by 7 @.@ 6 million viewers , coming in sixth for the night . Final consolidated figures ( not including BBC <unk> viewers ) showed that the episode was watched by 9 @.@ 87 million viewers , coming in fourth for the night . It also received an <unk> Index figure of 87 , higher than most of the Doctor Who Christmas <unk> . The <unk> version had 1 @,@ 467 @,@ 220 views , making it the most popular TV show on <unk> over Christmas . The US airing was seen by 1 @.@ 43 million viewers , with a 0 @.@ 6 rating in the demographic of adults aged 18 – 49 . 
