where does day of the doctor fit in
The Day of the Doctor The 77-minute episode shows the last day of the Time War, in which the War Doctor (John Hurt) chooses to kill both Daleks and his own race of Time Lords to end the destructive conflict, paralleling this with a present-day choice by paramilitary organisation UNIT to destroy London rather than allow an alien invasion. Revising the back story, the Doctor succumbs to Clara Oswald's plea to change his mind; and instead, at the last instant of the Time War, he hides his war-torn home planet in time, rather than destroy it. Unfortunately the time distortions incurred causes all but his latest incarnation to have no memory of his changed decision.
The Next Doctor The Doctor lands his TARDIS in London on Christmas Eve, 1851. Overhearing cries for help, he encounters a man calling himself "The Doctor" and his companion Rosita, attempting to capture a Cybershade. The Cybershade escapes the trio. The Doctor, in talking to the man, comes to believe he may be a future incarnation of himself, who is suffering from amnesia. The man, dubbed the Next Doctor, takes the Doctor to a nearby house of a recently deceased reverend, believing him tied to a series of disappearances around London and the Cybershade. Inside, they discover a pair of Cybermen data-storage infostamps, which the Next Doctor recalls holding the night that he lost his memories. The two are attacked by Cybermen and the Doctor attempts to fight them off with a cutlass, but the Next Doctor kills them using electrical discharge from the infostamps.