Do the green code one day and the yellow code the next. Can the green code be used as a plane on the same day?

Yes, you can. If there is a yellow code, you can't fly. The yellow code is not allowed to fly because it appears in the middle and high risk area. Green code can fly. If a yellow code appears, nucleic acid detection should be carried out. After the nucleic acid test results come out, the health code will turn green before flying. The "health code" is based on real data and can be generated by citizens or people who have returned to work through their own online declaration and background audit.