22 December

On 22 December 1963, the Fifth Doctor and Nyssa visited Switzerland, where they solved the mystery of a school haunting and prevented the Spillager invasion of Earth. (AUDIO: Winter for the Adept)

On same day in 2005, while in her Aunt's house in Devon, Sally Sparrow tore off a piece of wallpaper, revealing a message from 1985 asking for help. After later finding a photograph with the Ninth Doctor asking to look through the wallpaper again, she found another message leading her to play a video recording of the Doctor in 1985; the Doctor communicating to Sally through already having the conversation from Sally's uncompleted Christmas homework.

The Doctor explained that the TARDIS had "burped" forward in time twenty years to this year and needed Sally's help. Sally's future self appeared, telling Sally to hit the TARDIS reset button to reach the Doctor. The Doctor told Sally to finish her homework detailing this conversation and the messages left to her first, which she did. Sally then piloted the TARDIS to the Doctor to rescue him. (PROSE: What I Did on My Christmas Holidays by Sally Sparrow)

Behind the scenes

 * 1958 - Actress Tracy Louise Ward was born.
 * 1973 - Episode two of The Time Warrior was first broadcast on BBC1.
 * 1979 - Part one of The Horns of Nimon was first broadcast on BBC1.
 * 1993 - Actor Henry McCarthy died.