The End of Time: Part One

"The End of Time" is a two-part story of the British science fiction television series Doctor Who, originally broadcast in the United Kingdom on BBC One on 25 December 2009 (Part 1) and 1 January 2010 (Part 2). It is the fifth Doctor Who Christmas special and the last entry in a series of specials aired from 2008 to 2010. It marks the final regular appearance of David Tennant as the Tenth Doctor and introduces Matt Smith as the Eleventh Doctor. It was at the time, the last Doctor Who story written and produced by Russell T Davies, who shepherded the series' return to British television in 2005 and served as the series' executive producer and chief writer. He is set to return to that role in 2023 with the 60th anniversary special. Davies was succeeded as executive producer and showrunner by Steven Moffat.