It is a significant ceremony for citizens to take the oath after joining the army. It symbolizes the loyalty and responsibility of citizens to the country, and it is a solemn commitment and declaration. In many countries, including China, the time for taking an oath after enlistment is usually set within 90 days after enlistment. There is profound meaning and value behind this provision.

First of all, the stipulation that citizens take an oath after joining the army is a clear requirement of the state for citizens' responsibilities and obligations. Through this regulation, the state has conveyed firm faith and loyalty to every recruit, requiring them to express their commitment to the country at the initial stage after enlisting. This commitment is a solemn commitment to the country, society and people, and it is also a confirmation of its own value and mission.

Secondly, taking the oath after enlistment helps to establish the sense of honor and mission of soldiers. At the swearing-in ceremony, the recruits will solemnly swear in front of the national flag and the military flag, and they will give everything for the country, the people, the Constitution and even their families and relatives without reservation. Such a solemn commitment is a noble spiritual encouragement to every recruit, a conscious recognition of military identity, and helps to establish a firm belief and a lofty sense of responsibility.

In addition, it is stipulated that the swearing-in time after enlistment should not be later than 90 days, which is also helpful to cultivate the discipline and organization concept of recruits. The swearing-in ceremony is a formal military ceremony, which requires recruits to assemble, line up neatly, attend the ceremony and take the oath within a specified time. By limiting the time, this regulation urges recruits to adapt to the life of the army in time, learn to obey orders and observe discipline, and cultivate good military quality.

At the swearing-in ceremony, recruits usually solemnly swear: "Be loyal to the people of China and the Constitution of China, to the people and the country of China, to the people, to serve the people, to defend the people wholeheartedly, and to faithfully fulfill their national defense obligations." This oath bears the loyalty and responsibility of the recruits to the country and the people, and also entrusts the country with the trust and expectation of every recruit.