I know that 20 hours/week when school is in session and 40 hours when school is out is the legal maximum working hour for international full-time students in United States. I was wondering whether this also holds for students other than international students. The website of U.S. Department of Labor mentions the same, but it is not clear whether it holds for all. Here is the extract from the website.
"Full-Time Student Program
This program is for full-time students employed in retail or service stores, agriculture, or colleges and universities. The employer that hires students can obtain a certificate from the Department of Labor which allows the student to be paid not less than 85% of the minimum wage. The certificate also limits the hours that the student may work to 8 hours in a day and no more than 20 hours a week when school is in session and 40 hours when school is out, and requires the employer to follow all child labor laws. Once students graduate or leave school for good, they must be paid at least the federal minimum wage. There are some limitations on the use of the full-time student program..."