The Monday, Tuesday and Wednesday before the feast of the Ascension are Rogation Days or days of the 'Lesser Litanies', lesser as they are less ancient and celebrated with less solemnity than the 'Greater Litanies' celebrated on the 25th April.
Today, Monday of the Rogations, the Office is of the ferial day. At Mattins a homily from St. Ambrose is read at the nocturn. At Lauds the antiphon on the Benedictus is proper, Petite, et accipietis etc., as is the collect Praesta, quaesumus etc. Following this collect a commemoration of St. Boniface is sung followed by the Commemoration of the Cross. At the Hours all is taken from the ferial Psalter except the collect which is that which was sung at Lauds. At Prime the Dominical preces are sung.
After None the altar is vested in a violet antependium. The celebrant, vested in violet cope, assisted by deacon and subdeacon in violet dalmatic and tunicle reverence the altar then kneel and pray for a short while. They rise and the cantors begin the antiphon Exsurge Domine. The choir continue....adjuva nos, et libera nos, propter nomen tuam. Ps. Deus auribus nostris audivimus patres nostri annuntiaverunt nobis. Gloria Patri etc, Sicut erat etc and then Exsurge Domine is repeated. All all kneel (except the crucifer and acolytes who go and stand at the entrance of the choir) and the cantors then begin the Litany of the Saints. Each invocation is doubled, i.e. the cantors sing e.g. Pater de caelis, Deus, miserere nobis and this is repeated in its entirety by everyone else. When Sancta Maria, ora pro nobis has been repeated all rise and the Procession sets off.
The Procession goes outside of the Church and may visit other Churches on its route. In this case the celebrant is offered lustral water at the entrance to the church and processes to the High Altar. After a moment for silent prayer the choir signs the antiphon of the patron of the church, its versicle and response (with Alleluia added as it is Paschaltide) and the celebrant sings the collect of the Patron. The Litany is then resumed and the Procession continues. If the Procession has a long route the Litany, from Sancta Maria etc may be repeated or the Seven Penitential Psalms sung to the tonus in directum. When the Procession enters the church where Mass will be celebrated, lustral water is received on entering and the Procession goes to the sanctuary. All kneel as the Litany ends. The celebrant intones Pater noster etc and then the cantors sing psalm 69. After the versicles that follow the celebrant stands to sing the ten collects. He then kneels again as Exadiat nos etc is sung. The ministers then rise and the celebrant changes from a cope to chasuble and all put on their maniples. The Mass Exaudivit is then sung. The chants are those used for ferial Masses. The Gloria is not sung, the second collect is of St. Boniface and the third collect is Concede nos. The dismissal is Benedicamus Domino. The Paschal Candle is not lit.
Vespers are of the following feast of St. John Baptist de la Salle.
Those obliged to the Office who do not take part in Rogation Processions must recite the Litany on the three days.
In the 'liturgical books of 1962' when the Rogation Procession takes place the Litany may be sung in the vernacular if the faithful are present. The petitions are not duplicated. In the votive Mass that follows all the 'preparatory prayers' i.e. In nomine Patris..., Introibo ad altare Dei..., Judica me Deus..., Confiteor Deo..., the versicles, Aufer a nobis... and Oramus te, Domine are all cut out. The dismissal is Ite, missa est. However, the Ordinary may substitute other excercises/services in place of the Rogation Procession. Those not present at the Procession or other designated services are not bound to recite the Litany. Vespers are ferial.