The Holy Hour
A pious exercise of mental or vocal prayer, in union with the prayer of Our Lord in the Garden of Olives on Maundy Thursday night, when He wae abandoned by the Apostles.
It was taught as a practise to Saint Margaret Mary Alacoque by Our Lord Himself, who appeared to her in 1673, as she was in adoration before the Blessed Sacrament.
In 1829 Father Debrosse, S.J., founded a confraternity at Paray-le-Monial for the purpose of spreading this devotion, and in virtue of a rescript of Pius IX, 1875, the associates of the Apostleship of Prayer can gain a plenary indulgence by keeping the Holy Hour.
It may be practised publicly, when any hour may be named for any day in the week by the local directors; or in private, when the time is restricted between 2 P.M. on Thursday and 6 P.M.. on Friday.
No special prayers are obligatory but the Holy Hour should be offered in memory of Our Saviour's Passion, and in particular of His prayer and agony in the Garden of Gethsemani.
It has become a general and popular practise weekly in some parishes, and a favorite termination for parish missions, and for retreats of clergy and religious.
The best way of making it is by dividing the hour into quarters, devoting five minutes to points for reflection, five for silent prayer or meditation, and five for congregational singing.
New Catholic Dictionary