2000 Year Diary

The Two Thousand Year Diary was a journal kept by the Twelfth Doctor.

It was an updated version of his Twelve Hundred Year Diary, which was, in turn, a continuation of his Nine Hundred Year Diary. The Doctor used the Two Thousand Year Diary to remind himself of the Mire after they threatened a Viking village. (TV: The Girl Who Died)

Behind the scenes
In the second instalment of the parodical comic series The Daft Dimension, the Twelfth Doctor had an incredibly oversized copy of the Two Thousand Year Diary which he struggled to lift. (NOTVALID: The Daft Dimension)