A school year consists of two semesters. The first one ends at the end of January in all schools, the second one before the beginning of the summer holidays (see above). Primary and secondary school students usually have around 6 classes a day (less at the beginning of the education, more later). Classes last for 45 minutes, and there (several short ones and one longer one – the so-called "big break" (or by the students often just "big one")). The state financed education and all textbooks and instructional material below the university level are free (returned at the end of the semester) – in most cases at least. However, there are also private schools which are paid.