Presbyters are brought together and concelebrate this Mass as witnesses and co-operators with their bishop in the consecration of the chrism because they share in the sacred office of the bishop in building up, sanctifying, and ruling the people of God. This Mass is therefore a clear expression of the unity of the priesthood and sacrifice of Christ, which continue to be present in the Church (CB 274).
The Bishop and the priests of the diocese usually celebrate this Mass at the cathedral. It is a focal time for the priests to renew their commitment to their vocation. The name of the celebration refers to the blessing and consecration of the oils which are used during the year:
Lent ends on Holy Thursday, prior to the evening liturgy.
Since the Easter season lasts for seven weeks it is preferable for school celebrations to focus on the themes of Lent during Holy Week and reserve the celebration of the resurrection to the Easter season. This is counter-cultural to the commercial world where Easter products take prime place well before Easter and are removed from the shelves without any awareness of the actual Easter season.