12 months. Ningbo Vocational College graduated in one year 12 months with certificates. From the date of admission, you can graduate with a certificate after 12 months, that is, graduation in one year. If you want to enroll in an adult secondary school, you only need 18 years old to enroll. Ningbo, referred to as "Ningbo" for short, is a sub-provincial city in Zhejiang Province, a city with separate plans, an important port city in the southeast coast of China and an economic center in the south wing of the Yangtze River Delta approved by the State Council.