There is a difference between a seven week Life in the Spirit seminar and one that is on one day. The Doctrinal Commission of the International Catholic Charismatic Renewal Service (now known as CHARIS) provides the following discussion:
The Life in the Spirit Seminar was originally designed to be a seven-week program, modeled on the seven weeks of prayer and expectancy that Jesus’ disciples, including his mother Mary, lived from the Resurrection until Pentecost. On the fiftieth day, “they were all filled with the Holy Spirit and began to speak in other tongues, as the Spirit gave them utterance” (Acts 2:4).
Today, the Life in the Seminar is sometimes done in a two-week format, or over a weekend, or even in a single day. For some groups, these are the only feasible options due to various pastoral circumstances. However, they are less than ideal. Whenever possible, it is best to use the full seven-week format. In some cases, where people are unfamiliar with the gospel message, a longer format such as three months or a year is even better.
The Seminar is not only a matter of listening to talks, but of following a path of deep conversion, breaking with a life of sin, obtaining inner healing and liberation. People discover anew the Father’s love, come to know Jesus’ salvation and lordship, and are equipped to become his disciples and witnesses in the world. It is only after this formation and conversion that people are ready to receive a deeper outpouring of the Spirit and his gifts.
If there is insufficient preparation, the prayer for baptism in the Spirit will usually not bear the expected fruit of holiness, nor will it bring authentic charisms to serve the body of Christ in the power of the Holy Spirit.
Of course, God sometimes sovereignly baptizes people in the Holy Spirit apart from a Life in the Spirit seminar, for example through the sacrament of Confirmation if its preparation stresses the same themes as the Seminars. God pours out his Spirit when he wills.
— Charismatic Renewal International Service (CHARIS),
