In the movie Schubert becomes the music theater for the family of Esterházy in 1822. In real life he was already working there in 1818. He also worked that in that year for 6 months, not for 3.
In the movie Caroline Esterházy married a military officer in 1822 in Hungary. In real life she only married count Karl Folliott de Crenneville-Poutet in 1844. Also it happened in Bratislava, Slovakia.
Various pieces of Schubert's music are set to incorrect time periods. At the beginning of the movie the cleaning women is singing Schubert's song "Am Brunnen vor dem Tore", which was written in 1828, while the scene was set in the 1810s. When teaching Caroline Esterhazy rhythm Schubert uses his song "Leise flehen meine Lieder", which was written in 1828, long after his engagement at Esterhazy.
When discussing the house of Esterházy, Schubert's friend calls it "Hungarian Rhapsody", referring to the famous pieces by Franz Liszt. However they were written in the 1840s, while the scene is set in 1822.
The musical event of Countess Kinsky is announced on Thursday, the 23th May. A year is not mentioned but since Schubert is playing motives from his symphony in b minor, it identifies the year as 1822. It is set up that that the movie is set in the same year. But only a few moments Schubert is seeing writing the melody for "Heindenröslein", which was actually written in 1815.
The movie's plot is set around the relationship between Schubert and Caroline Esterházy and that he gives her the "incomplete" symphony in h minor. In real life Schubert worked for Esterházy in 1818 and 1824, while the symphony was written in 1822 and is unrelated with Esterházy at all.