20 April

20 April 1889 was infamous for being Adolf Hitler's birthday. In 1945, on his 56th birthday, Hitler was seen for the last time outside the Nazis' underground bunker in Berlin, giving awards to some members of the Hitler Youth. (PROSE: ''The Shadow in the Glass)

In 2011, Craig Owens awoke to find the Eleventh Doctor gone following the events of the day previous; the Doctor went to Sanderson & Grainger on his own to battle the Cybermen. Craig joined him and was almost Cyber-converted, but managed to reverse the process half-way through when his son Alfie's cry rebooted his emotions. This also caused an emotional overload for the Cybermen; their ship was destroyed in the explosion. Despite supposedly having little time to live, the Doctor then travelled back a few hours to clean up Craig's house before Sophie returned, and then left for one last trip in his farewell tour and to finally confront his death. (TV: Closing Time)