Twice a day new crown nucleic acid testing means two new crown nucleic acid tests within 24 hours, based on the time of sampling. The so-called twice a day new crown nucleic acid test means that two nucleic acid tests need to be completed within 24 hours. It is mainly for people who have a higher risk of infection such as those who have a history of traveling in some medium to high-risk areas, and can be completed within the specified time according to the specific requirements of the local area. However, it should be noted that twice a day refers to the sampling time, not the time when the results are issued. In some areas, due to the pressure of nucleic acid testing, it is not possible to give the results of two nucleic acid tests within 24 hours, so the sampling time is generally used as the basis, which requires special attention.