How Many Times Can One Receive Communion In A Day?

A reader writes:

I have a sacrament and liturgy question; to wit:  In your reading of canon Law ( Canon 917 in particular), and any additional notations or opinions on that canon (or pronouncements from the US CCB), how many times may an individual (not the celebrant) receive communion in one day (my definition of "day" being one calendar day of the same date, vs. any 24 hour period)? 

Your definition of "day" is the same as the Code of Canon Law’s definition:

Can. 202 §1.
In law, a day is understood as a period consisting of 24 continuous hours and begins at midnight unless other provision is expressly made.

Since other provision is not made in Canon 917, that’s the definition of "day" that is operative there.

Canon 917 deals with the number of times one may receive Communion:

Can.  917
A person who has already received the Most Holy Eucharist can receive it a second time on the same day only within the eucharistic celebration in which the person participates, without prejudice to the prescript of can. 921, §2.

Canon 921, §2 deals with the case of Viaticum for the dying, so it does not concern us here.

As a result of canon 917 and Canon 202, a member of the lay faithful can receive holy Communion twice in a twenty-four hour period spanning midnight to midnight, barring the exception of receiving it a third time as Viaticum.

The reader continues:

The specifics arose recently when two Extraordinary Ministers for Holy Communion attended 2 funeral masses during the day on a Saturday (receiving Holy Communion at both), and then participated (as EMs) in the vigil mass that evening.  Should they have declined to receive communion at the vigil Mass? 

Yes, they should have declined, as per the above.

I understand the general rule is that one may receive communion at a second Mass if the whole sacrifice of the Mass is participated as part of the second reception. 

This is mostly correct, but there is no requirement that one be participating in the whole of the Mass at the second reception. Canon 917 simply refers to participating in the Mass, not participating in the whole of it or the whole of any part of it (if one is considering the sacrifice as occurring, e.g., in the Liturgy of the Eucharist). This provision of Canon 917 is meant to distinguish the second reception from Communion from cases where one receives it outside of Mass altogether. This is provided for in the following canon:

Can.  918
It is highly recommended that the faithful receive holy communion during the eucharistic celebration itself. It is to be administered outside the Mass, however, to those who request it for a just cause, with the liturgical rites being observed.

So the first time one receives Communion, it may be in a Mass or outside of Mass (Can. 918), but the second time it must be in a Mass in which one is participating (as opposed to one where one happens to walk through Church at Communion time). This would indicate substantial participation in the Mass, but not participation in all of it.

I argued with our pastor that the vigil Mass (considered as meeting our Sunday obligation) could be treated as Mass for the next day for the purposes of this "rule."    Is there anything published within the Church that further addresses or elucidates this matter?

Yeah, it seems to me that Canon 202 deals with the definition of "day." There isn’t anything in 202 or 917 allowing for a "vigil" Mass. This concept is never mentioned in the Code of Canon Law (the relevant canon simply speaking of fulfilling one’s Sunday/holy day obligation at a Mass falling on the evening of the preceding day, not a special "vigil" Mass occurring then). While Masses are celebrated on the vigils of certain days using the following day’s readings under liturgical law, it is not liturgical law that determines how many times one can receive Communion.

Canon law does that, and in the absence of a re-definition of the word "day" in Can. 917 to allow for this,  Can. 202 is going to govern the situation, meaning that one cannot receive twice and then receive again at a "vigil" Mass later in the day.

Hope this helps!