Four to five months. According to the relevant information of Aopeng Education official website, the post office of the graduation certificate of Aopeng Headquarters depends on the audit process of the education department, the handling and time flow of the local postal department, and the mailing time is 4 to 5 months. Open education is a public service system of modern distance education approved by the Ministry of Education. Open education is based on the Internet platform, which provides consultation for the academic upgrading of distance education (online education).