在Post-completion OPT 期间，一周工作20小时算part-time还是full-time?

我现在处于Post-completion OPT期间,目前有个一周20小时(不多也不少)的实习。我问了学校有关老师，他答复是一周20小时算作full-time，但是我看USCIS的官网的定义"Post-completion OPT: F-1 students may apply to participate in post-completion OPT after completing their studies. Students authorized for post-completion OPT may work part-time (at least 20 hours per week) or full-time." 感觉一周20小时是算在part-time里面的，所以对此有些迷惑。