Classes are generally held during the day. Some are held on nights and weekends to accommodate students who have jobs or family obligations. Many postsecondary teachers do not teach classes in the summer, but they use that time to conduct research or to travel. Other postsecondary teachers teach summer courses.
Postsecondary teachers’ schedules are generally flexible. Postsecondary teachers need to be on campus to teach classes and keep office hours. Otherwise they are free to set their schedule and decide when and where they will prepare for class and will grade assignments.
About 29 percent of postsecondary teachers worked part time in 2010. Some postsecondary teachers work part time at several colleges or universities.
Most graduate teaching assistants work part time while also studying for
their degree. The number of hours they work may vary, depending on the
institution and their particular assistantship..
Source: Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2012-13 Edition