How many years can a female employee of China Petroleum Company not apply for night shift after giving birth?

Referring to the provisions of the labor law

Three. The employer shall not extend the working hours beyond the normal working days due to restrictions on overtime and night shift of female employees during pregnancy. If a female worker is not competent for the original job, she shall reduce the workload or arrange other work according to the certificate of the medical department. The employing unit shall not arrange female employees who have been pregnant for more than seven months to extend their working hours, and generally shall not arrange them to engage in night work, and shall arrange certain rest time during working hours.

During the lactation period, the employer shall not extend the working hours of female employees, and generally shall not arrange them to engage in night work.

Therefore, you can apply for not breastfeeding at night, which is roughly 12 months.