Through the sacrament of Confirmation, the baptized are more perfectly bound to the Church and are enriched with a special strength of the Holy Spirit. Hence they are, as true witnesses of Christ, more strictly obliged to spread and defend the faith by word. 

Catechism of the Catholic Church Page 326

Confirmation, conferred by a Bishop, is received by children in the seventh grade usually in the Spring of the year. Adults who have never been confirmed may receive the sacrament, after appropriate preparation, with the children or if they are enrolled in the RCIA Program they may receive Confirmation at the Easter Vigil or at the Cathedral on Pentecost Sunday.