Each month on the Roman calendar is dedicated to a specific devotion. September is dedicated to Our Lady of Sorrows.
During the Middle Ages the public functions of the Church and the popular devotions of the people were intimately connected. Lay people and religious assisted at the daily psalmody, the sacrifice of the Mass, the numerous processions, and were quite familiar with the liturgy. Those few religious practices outside of official services, e.g. the Rosary (a substitute for the 150 Psalms) originated in the liturgy.
Later, however, especially since the 16th century, popular devotion followed its own channels; non-liturgical practices like the Stations of the Cross, various litanies and chaplets, prevailed everywhere; novenas and series of Sundays and week-days in honor of particular saints or mysteries were instituted. Entire months of the year were given over to special devotions.
On September 15 we celebrate the feast day of Our Lady of Sorrows. The object of this feast is the spiritual martyrdom of the Mother of God and her compassion with the sufferings of her Divine Son. Read more about the Seven Sorrows.
Speaking of less well known devotions, have you ever heard of the Pardon Crucifix? I didn’t think so.