Any amount of hours that do not exceed 40 hours per week are considered part-time hours. Most companies consider the traditional part-time hours to be 20 to 37 1/2 hours per week.
However, under the Obama administration, new part-time hours have been re-defined as 30 hours per week or more. This law is designed to deter small business owners from hiring more part-time workers, which actually costs the business more money, and to make sure that part-time workers get more work hours and more benefits from their employers. The ObamaCare administration also mandates that small businesses that employ 50 employees or more are to provide health care insurance for their workers.