- You may be looking for 24 December.
Due to his rudimentary knowledge of Earth, Mr Copper believed that the people of the UK went to war with Turkey every Christmas Eve, after which they would then eat the people of Turkey for Christmas dinner. (TV: Voyage of the Damned)
In 2006, the newly-regenerated Tenth Doctor crashed his TARDIS into the Powell Estate, choosing the date as a Christmas present for Rose Tyler. Later that day, Rose was attacked by Robot Santas while out Christmas shopping with Mickey Smith. When they arrived back home, they were attacked by a Roboform Christmas tree. Later that night, the Sycorax made first contact with Earth. (TV: Children in Need Special, The Christmas Invasion)