High school teachers generally work school hours, which vary somewhat. However, they often spend time in the evenings and on weekends grading papers and preparing lessons. In addition, they may meet with parents, students, and other teachers before and after school. Plus, teachers who coach sports or advise clubs generally do so before or after school.
Many work the traditional 10-month school year, with a 2-month break during the summer. Although most do not teach during the summer, some teach in summer programs. Teachers in districts with a year-round schedule typically work 8 weeks in a row, are on break for 1 week, and have a 5-week midwinter break.
Source: Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2012-13 Edition