How many days does Zhengzhou work in secret?

Fifteen days. Close contact means keeping a distance of less than 2 meters from the infected person for more than 15 minutes. This definition includes both the definition of distance and the definition of time. Secret workers need to be quarantined for fifteen days before they can go to work. Zhengzhou, known as Shangdu in ancient times, is the capital of Henan Province, a mega-city, the core city of Central Plains urban agglomeration, and an important central city in Central China determined by the State Council.