When did Chaoan private enterprises start to buy social security?

Within 30 days. Private enterprises, referred to as private enterprises, companies or enterprise categories, refer to all non-public enterprises. Because employers and employees must buy social security for employees within 30 days from the date of signing the labor contract, Chaoan private enterprises must buy social security for employees within 30 days. Social security is the abbreviation of social insurance, which refers to five kinds of insurance: endowment insurance, medical insurance, maternity insurance, unemployment insurance and industrial injury insurance.