I don’t think teachers consider evenings or weekend “personal time”. When do you think teachers grade assignments, or prepare their lesson plans? They certainly aren’t given enough time during the school day to complete those tasks.
Like many professionals, high school teachers are usually salaried employees who are expected to complete all sorts of tasks outside of regular school hours. Unlike some professionals, teachers are often underpaid for the value of the work they do. The tradeoff is that they get a long summer break.