The high incidence of cardiovascular and cerebrovascular events is between 6am and 12pm, while enteric aspirin takes 3-4 hours to reach its peak blood level after consumption. In addition, at night, the human body is less active, the blood is sticky, and platelets are easily aggregated, therefore, enteric aspirin is more effective when taken at night. It should be emphasized that the efficacy of aspirin depends on the assessment between thrombosis and bleeding. For low-risk patients, such as men at cardiovascular risk and patients with essential hypertension, the benefit is similar to the risk and aspirin needs to be chosen with caution. Conversely, for patients at high risk, such as those with chronic stable angina, previous myocardial infarction, and unstable angina, the benefits far outweigh the risks and can be considered in those without contraindications.