A Feast Day in the Catholic Church marks the liturgical celebration of a saint. Its establishment is a recognized stage in the canonization process, following a lengthy Church investigation into the life and virtues of a deceased person. This investigation gathers evidence of holiness, including miracles attributed to their intercession. If sufficient evidence is found, the individual is beatified, a preliminary step. Further investigation and evidence of additional miracles are then required. Only after a thorough review and a declaration by the Pope can someone be canonized and have a Feast Day established, officially recognizing their holiness and inviting the faithful to commemorate their life.