Persons require about 1-3 years of formation to prepare for full Christian initiation. The normal time to “be fully initiated” (receive Baptism, Confirmation, and Holy Communion) is during the Easter Vigil.
The Order of Christian Initiation
Step 1: Period of Evangelization and Precatechumenate
This is a time of discovering the Catholic faith and the Church. There is no fixed duration or structure. When an inquirer is ready, the Rite of Acceptance marks the end of this period.
Step 2: Period of the Catechumenate
This is a lengthy time of focused learning and solid spiritual formation. When a catechumen is ready, the Rite of Election marks the end of this period.
Step 3: Period of Purification and Enlightenment
This is a short time of retreat-like preparation during Lent for the Elect. The end of this period is the Celebration of the Sacraments during the Easter Vigil.
Step 4: Period of Postbaptismal Catechesis or Mystagogy
This is the beginning of the neophyte's sacramental life.