Can Peixian Guotai get a health certificate on Sunday?

You can't.

Peixian Cathay Pacific is a public institution, and employees of the company are resting on Saturday and Sunday, so they do not apply for health certificates.

Health certificates are generally issued by the Municipal Center for Disease Control and Prevention, and medical institutions authorized by the Center for Disease Control and Prevention can carry out health certificate physical examination services. The list of filing units can be found on the website of municipal CDC, and other medical institutions do not have the function of providing related services. Individuals need to carry their ID cards and go to CDC or authorized medical institutions for physical examination on an empty stomach on weekdays.