We can obtain one plenary indulgence each day.
Indulgences can be applied either to oneself or to the souls of the deceased. They cannot be applied to other living persons.
In addition to the described work, to obtain a plenary indulgence we must fulfill the following conditions:
1) GO TO CONFESSION! A single sacramental confession suffices for gaining several plenary indulgences, and Communion must be received.
2) Prayer for the intention of the Sovereign Pontiff must be recited for the gaining of each plenary indulgence. This is satisfied by reciting one Our Father and one Hail Mary. However, we are free to recite any other prayer according to our piety and devotion.
3) All attachment to sin, even venial sin, must be absent. If you are not free from attachment to sin, even venial, or if the prescribed conditions are not fulfilled, the indulgence will be partial only.
A confessor or the local ordinary can commute the work or conditions if a person is legitimately impeded.
The three conditions may be fulfilled several days before or after the performance of the prescribed work. However, it is fitting that Communion be received and the prayer for the intention of the Pope be recited on the same day the work is performed. How many days is “several days”? Traditionally, it was said 8 days. However, in 2000 for the Jubilee, the Sacred Apostolic Penitentiary said 20 days. Later, it was asked if that applied only to the Jubilee Year. The same SAP said that it applied to the general norms. So, the highest authority in the Church (apart from the Pope) on indulgences says “20 days”, though you are free to stick to getting everything done within 8, as we always did before.
Reverend Fathers, teach about indulgences. Everyone, strive to obtain them!
via Fr. Z