The word novena is a derivative of the number nine, which refers to the length of time this prayer would last because of the first novena that was said.
Our Lady, along with the apostles, gathered in the upper room after the ascension of the Lord into heaven for nine days of prayer. They did so to prepare for the coming of the Holy Spirit. On the tenth day the Holy Spirit descended (the Solemnity of Pentecost). Pentecost means fifty since it takes place fifty days after Easter.
Novenas can be divided into various categories: to our Lord, our Lady, the saints, and angels. Novenas are usually short prayers that are said consecutively for nine days.
However, a novena can be celebrated in a more solemn way. It is customary for the titular saint of the parish to be honored with nine nights of prayer. During these services, prayers to the saint would be said, a priest would expound upon the virtue of the saint, and benediction of the Blessed Sacrament would conclude the devotion. This period of nine nights of prayer is especially popular during the season of Lent, in which Catholics often attend spiritual programs as part of their preparation for Easter.
Novenas can also be perpetual. Instead of nine consecutive nights, they can be prayed every week. The Miraculous Medal Novena is often prayed in Catholic parishes every Monday, either after Mass or with benediction.
Saint Catherine Laboure received in 1830 an apparition of Our Lady, in which the Blessed Mother asked Catherine to construct a medal in honor of her Immaculate Conception, with the inscription: O Mary, conceived without sin, pray for us who have recourse to thee… There is also a wonderful devotion to Saint Anthony of Padua, known as the Thirteen Tuesdays in Honor of Saint Anthony.
Saint Anthony died on June 13, which is the day that the Church celebrates his entrance into heaven. To prepare for this feast, special prayers, devotions, and litany to Saint Anthony are said for thirteen Tuesdays leading up to June 13.
Another popular novena is the Rosary Novena. For thirty days, certain prayers which accompany the Rosary are said during this special novena. The Rosary Novena can be prayed at any time of the year. Finally, there is the Christmas Novena, thirty days of prayer which is a way of preparing for this Solemnity.