For the Canadian broadcast, Christopher Eccleston recorded special video introductions for each episode (including a trivia question as part of a viewer contest) and excerpts from the Doctor Who Confidential documentary were played over the closing credits; for the broadcast of "The Christmas Invasion" on 26 December 2005, Billie Piper recorded a special video introduction. CBC began airing series two on 9 October 2006 at 20:00 E/P (20:30 in Newfoundland and Labrador), shortly after that day's CFL double header on Thanksgiving in most of the country.[citation needed]
Which special occasion was the focus of an episode?