The 900 Year Diary was a journal kept by the Seventh Doctor. (TV: Doctor Who)
Eventually, the Doctor lived long enough to require an even further updated diary, as the Eleventh Doctor possessed a 1200 Year Diary, (TV: The History of the Doctor) the Twelfth Doctor came to possess a 2000 Year Diary, (TV: The Girl Who Died) and the Thirteenth Doctor owned a Five Thousand Year Diary. (GAME: Lost in Time)
