The film is set in 1943 but Susan tells Sammy that it's Tuesday the 23rd of May. The 23rd didn't fall on a Tuesday in 1943, although it did in 1939 and 1944.
A little over 75 minutes into the film, during the scene where the character of Sammy Rice trashes his sitting room, the shadow of the boom mic can be seen reflected in the empty picture frame in the foreground of the shot.
The ATS corporal mentions the Pavilion End at Wembley. There was no such end.