The 6th of September 1959 was a Sunday, not a Thursday, as suggested in the movie.
The movie is set in 1959. Jimi sings "Stand by me", which was first released by Ben E. King in 1961.
Lulu listens to "Let's Dance" in her room, a song that was first released by Chris Montez in 1962, three years after the movie's setting.
The movie is set in Schweinfurt, but Lulu's car has the license plate for "SF", which in 1956-1979 for the region Sonthofen in South Bavaria, over 330km away from Schweinfurt.