Given the importance that the ordination of a bishop, a priest, or a deacon has for the life of the particular Church, its celebration calls for as many of the faithful as possible to take part. It should take place preferably on Sunday, in the cathedral, with solemnity appropriate to the occasion. All three ordinations, of the bishop, of the pRiest, and of the deacon, follow the same movement. Their proper place is within the Eucharistic liturgy.
Source: Catechism of the Catholic Church (Vatican.va)