How long does it take?
The Rite of Christian Initiation is not a program.
It is the Church's way of ministering sensitively to those who seek membership.
For that reason some people will need more time than others to prepare for the lifetime commitment that comes with membership in the Catholic Church.
The usual length of preparation is from one to two years.
For those already baptized and who seek full communion in the Catholic church, the time may also vary.
It seems reasonable that catechumens or candidates experience the yearly calendar of Catholic practice at least one time around in order to make an informed decision.
The process of spiritual renewal and catechesis should not be hasty, especially for those not accustomed to the fasts and feasts and Sundays and seasons the way Catholics observe them.
One of the best time for the Sacraments of Initiation or the Rite of reception into full communion is the Easter Vigil. Lent prepares catechumens, candidates and the whole community for Baptism, Confirmation and Eucharist.
The celebration of the Easter Vigil dramatically points to the wellspring of the church's life:
"The Death and Resurrection of Jesus Christ."