Doctor Who fans from around the world will be able to watch the show's 50th anniversary episode at the same time. The feature-length installment of the sci-fi favourite is set to be shown on the BBC on 23 November (13), when current time lord Matt Smith will appear alongside his predecessor David Tennant, and producers have announced the episode will be broadcast in at least 75 countries, including the U.S., Brazil, Canada, Australia and Mexico, at once. Executive producer Steven Moffat says, "The Doctor has always been a time traveller - now he's travelling time zones. On the 23rd of November... it will be 'The Day of the Doctor'!" Smith will step down as Doctor Who at the end of the year (13), and he will be replaced by the 12th TV time lord, Peter Capaldi.