” Following this lead, Canon 921, §2 stipulates, “Even if they have received Communion in the same day, those who are in danger of death are strongly urged to receive again.” Succinctly, a Catholic may receive Holy Communion twice a day.
Obligation for receiving Holy Communion
In ordinary circumstances, an individual is obligated to participate fully in the entire Mass; making an offering of oneself to the Lord. The person ought to be present from the very beginning until the very end of the Mass; giving full attention as best one can. Such full participation and attention dispose the individual to receive Holy Communion. The worthy reception of Holy Communion not only enables the individual to enter into communion with the Lord but also binds that individual in a communion of faith and love with the other members of the Church.
Never, in ordinary circumstances, do we isolate the reception of Holy Communion from the rest of the Mass. The Church grants the permission of receiving Holy Communion twice in one day to meet those situations of a person attending perhaps a wedding Mass and a funeral Mass on the same day, or attending the regular daily Mass and then some special Mass the same day; nevertheless, the stipulation is that the person attends the whole Mass in both instances.
Special circumstance for receiving communion
As qualified in Canon 921, §2, in those special circumstances when a person is in danger of death, then he may receive Holy Communion as viaticum along with Penance and Anointing of the Sick, even though he may have received twice already that day.
Another special circumstance arises when the person is confined in a hospital or homebound: here the person may receive outside the context of Mass, but would not receive more than once a day unless in danger of death.