Actually, it’s around 184 working days per school year. However, teachers who are good teachers typically work 50 hours a week at school, not including the time spent at home grading papers. I work with teachers who are in the classroom 1.5 hours before their students, and who do not leave school until 5:00 pm or later (2+ hours or more after the students have gone home). Of course, there are teachers who arrive just before the students and leave shortly after the students (fulfilling the minimum contract hours). Many of the teachers who put in the extra time also work during summer school (now down to approximately 4 weeks from 6 weeks).