QUAERITUR: Do I follow the law from back home when I am travelling?

From a reader:

What should one do when one is travelling on an HDO? Should one follow the rule for the diocese one is actually in, or the one where one resides? What if one is on the plane during the day? How does one know which rule to follow? My husband and I have actually had this dilemma and didn’t have a clue what to do.

HDO…. HDO… I assume this means Heavy Derrick Operator.

If you are traveling on a Heavy Derrick Operator, then please get off now. I don’t think that either he or your husband will approve of this odd way of traveling, and you may be getting into all sorts of problems with unions and overtime.

St. Augustine recounts an episode about his mother, St. Monnica, when she was with him in Milan.  Monnica carried on with her North African custom of refrigeria meals (called laetitia in Confessions 6.2.2) in cemeteries by the tombs of the dead.  This  raised many Milanese eyebrows, including those of bishop Ambrose.

Augustine says that Ambrose instructed Monnica not to do this in Milan, for it was not their local custom.  Ambrose said that when he was in Rome, he followed the Roman laws concerning fasting, which were different from those of Milan: “When I am here I do not fast on Saturday, but when I am at Rome I do; whatever Church you may come to, conform to its custom”  (cf. Augustine ep 36.14.32 and ep 54.2.3).

In other words, when in Rome you do as the Romans do.

We follow the local rules of the place where we are, according to our Church.  Latin Church members follow Latin Church rules of the local Latin diocese even if they go to a Ukrainian Catholic Church for Divine Liturgy that day.

And, yes, this applies to HDO.

I also applies to Holy Days of Obligation.

But, make sure to check if Thursday, Ascension THURSDAY, has been transferred to Ascension Thursday Sunday in the place you actually observe it.

About Fr. John Zuhlsdorf

Fr. Z is the guy who runs this blog. o{]:¬)
This entry was posted in "How To..." - Practical Notes, ASK FATHER Question Box and tagged . Bookmark the permalink.


  1. They can always say the Office for Ascension Thursday. I don’t think it matters if you don’t have a canonical obligation to say the Office.

  2. pseudomodo says:

    We presume that the place that you are in is following the rubrics!

    When in Rome do as the Romans do. When not in Rome, do as the Romans do! We are under no obligation to follow poor or wrong liturgy.

  3. CharlesG says:

    When traveling with a group in Italy to see the Shroud of Turin last year, the American chaplain for the group celebrated Ascension twice — once on Thursday following the (eastern) US rule, and once on Sunday following the Italian rule (I think he didn’t realize the rule that you follow the locality until after the Thursday mass). What a mess! I just hope other bishops’ conferences will take their cue from the English and Welsh bishops and move Ascension and Epiphany back to their proper days. At least the eastern US bishops have the sense to keep Ascension on Thursday.

  4. Willebrord says:

    Father, in our diocese the Ascension is Ascension Thursday (today), and we are parishioners of a diocesan parish.. However, we live on a military base in this diocese, and since the chapel on post is part of the military archdiocese, Ascension is on Sunday. Are we under the obligation of the military archdiocese or of the diocese, for which day to celebrate the Ascension?

    It’s not a serious matter since we already go to the Mass in the parish on Ascension Thursday, but I’m curious.

  5. One year I took my vacation from Ascension Thursday to Pentecost Sunday. Before leaving on my cross-country drive, I attended Mass here in New York on Ascension Thursday, where it is still a holy day of obligation. Not wanting to get a second Ascension Thursday Mass the following Sunday, I made sure that on Sunday I landed in the only other state west of the Mississippi River to observe Ascension Thursday on Thursday– Nebraska. After that, I decided that I am better off staying home during that time and vacationing at other times where liturgical tinkering is not prevalent.

  6. That passage from Augustine made it into the Decretum of Gratian (D. 12 c. 11) and so was part of the legal patrimony of the Church until the 1917 code. The following two glosses from the Ordinary Gloss on that passage in the Decretum elaborate on the principle. Note that if one is merely passing through, one is not even bound by the local custom. Although “some” canonists mentioned in the gloss suggested that the traveler passing through quickly should follow Roman practice as it is a model for the whole Church. But the consensus of the Decretists was that the rapid traveler need not follow any custom, not even Roman.

    f community?So it may be argued that everyone is bound to live according to the custom of those among whom he lives, as here and D. 8 c. 2; D. 41 c. 1. B. Hence the verse: “When in Rome, do as the Romans do, and when elsewhere, live as they.”
    g where you are?So it may be argued that travellers are bound to follow the custom of the place where they are, as here and in D. 8 c. 2. To the contrary, see Dig. 5. 1. 19. The solution is as noted in D. 100 c. 8, because it depends on whether they will stay or leave quickly, and whether the custom is obvious or not.

  7. I’m no canon lawyer; but I would think that when you’re on the post you’re physically in the US military archdiocese, and when you’re in the parish you’re physically in the parish’s archdiocese. It’s like embassies are legally part of the country they represent, even if they’re completely surrounded by the other country that gave them the land. (Different Rites being a different matter.)

  8. Rachel says:

    “When in Rome, do as Romans do.” Hobbes applied that rule in a Calvin and Hobbes strip:


  9. Jerry says:

    @Fr. Thompson – the same principles are codified in canon 13 sec. 2:

    Can. 13 §2 Peregrini [travelers] are not bound:

    1° by the particular laws of their own territory while they are absent from it, unless the transgression of those laws causes harm in their own territory, or unless the laws are personal

    2° by the laws of the territory in which they are present, except for those laws which take care of public order, or determine the formalities of legal acts, or concern immovable property located in the territory.

    §3 Vagi [transients] are bound by both the universal and the particular laws which are in force in the place in which they are present.

  10. diffal says:

    “But, make sure to check if Thursday, Ascension THURSDAY, has been transferred to Ascension Thursday Sunday in the place you actually observe it. ”

    I got caught out like this a few years ago. The diocese where I live observes Ascension Thursday, I went to visit my family in my home country where they observe “Ascension Thursday” Sunday. I travelled from my family home back to my own home on the Friday in-between these two days forgetting about the calendar nonsense and I managed to completely miss the feast of the Ascension. The sooner they bring back Ascension Thursday the better!

  11. Cath says:

    “HDO…. HDO… I assume this means Heavy Derrick Operator.”

    Thank you, I needed a good laugh today!

  12. Catholictothecore says:

    Laughed out loud as well! You’re hilarious sometimes, Fr. Z. God Bless you!

  13. jvacek says:

    Had it happen in college where I went home from MO to NE the weekend after Ascension Thursday and so missed out on the Ascension. College diocese transferred it to Sunday, and home diocese kept it on Thursday.

  14. James Joseph says:

    If go to the Extraordinary Form 99.9% of the time, can I get out of some obligation, like say… fasting during the ember days, by putting on polyester slacks and heading off to the local Ordinary Form for that one weekend?

  15. LawrenceK says:

    I missed Ascension entirely one year, because I was on the West Coast on Thursday and then in Arkansas on the 7th Sunday in Lent.

    Maybe someday we will have colonists on the Moon and on Mars. If you think your calendar woes are difficult, just think of what theirs will be!

  16. Chatto says:

    I had the same thought as pseudomodo. I’ve just returned from Bruges in Belgium, and went to three Masses. At each, there was no kneeling whatsoever, and the congregation joins in with the Per Ipsum (they were all OF). I was happy to follow the rest of their customs, but knelt (on the floor, because no church I saw had pews – they have individual chairs) during the consecration, and didn’t join in during the Per Ipsum.

  17. Fr. Basil says:

    \\Latin Church members follow Latin Church rules of the local Latin diocese even if they go to a Ukrainian Catholic Church for Divine Liturgy that day.\\

    Could you please explain what you mean by this, Fr. Z? [Pretty straight forward. Latin Church Catholics are bound by the Latin Church Code of Canon Law, not the Eastern Church Code.]

  18. teomatteo says:

    I agree with Father Z. When I travel i prefer the EF, Electrodiesel Frieghter. This i enjoy more than being stuck with an OF, Oceanic Frigate.

  19. RCGuerilla says:

    Yesterday the church was empty for the mass at 630 PM (BTW I live in Brazil). I never thought to check or ask. In Brazil they rolled over Ascension Thursday to Sunday. I know Boston and a few other Archdiocese back home (US) still celebrate it on Thursday.

  20. helgothjb says:

    If you live on a US military base you are in the military Archdiocese.

  21. Jim of Bowie says:

    A similar problem occurs because of the two calendars. My diocese celebrates Ascension on Sunday. I will be attending a TLM on Sunday where the mass for the Sunday after Ascension will be said. Have I failed to meet my obligation?

  22. Jim of Bowie, the obligation is to assist at Mass on the day or the afternoon/evening before (I am not sure at which point of the evening before Mass covers the Holy Day obligation). Unless I am very much mistaken, there is no obligation to attend a Mass with a specific set of readings or prayers, simply to assist at Mass.

    However, if there is a TLM on the Thursday, it would perhaps be wise for the priest to arrange it at such at time as would facilitate people’s assistance at the Mass even if they have to work on the day. It would then surely make sense to try to assist at the EF Mass on this day. However, that is a different matter from having an obligation to attend.

  23. The Dublin Latin Mass chaplaincy, for instance, has Mass at 8am on ordinary weekdays, but 8am and 7pm on working Holy Days. In Ireland, Holy Thursday has been transferred to Holy Thursday Sunday so the obligation to attend Mass on the actual Holy Thursday has been removed, but there is then still the opportunity to assist at the Holy Thursday Mass in the Extraordinary Form.

  24. thoscole says:

    What if, for instance, you started the day in the Province of Baltimore, where the obligation is transferred to Sunday, but later in the day went to the Province of Philadelphia, where the obligation is in force? Would there be an obligation to attend an evening Mass there, if feasible? Would it matter whether or not you lived in Pennsylvania, or were only visiting for the evening?

  25. RichardT says:

    I think we discussed this on this blog a few years ago, and from memory, Jerry’s quote (5:28pm) was settled on as being the right answer.

    Under that there are 3 situations:

    1) If you are in a diocese where you have (or are taking up) a regular residence, you follow the rules of that diocese. So (I think; I’m not a canonist) if you regularly live during the week in a diocese that keeps Ascension on the Thursday, and regularly live during the weekend in a diocese that moves it to Sunday, you have to do both.

    2) If you live regularly in a diocese, at any time when you are temporarily outside that diocese you are not (generally) bound by the particular rule of either your home diocese or the diocese you are temporarily in, but only by the general laws of the Roman Church (which I think means Ascension Thursday is on Thursday).

    3) If you don’t have any fixed abode, you are bound by the rules of whichever diocese you happen to be in at the time.

    Obviously there’s room for discussion as to what counts as a regular residence in a diocese.

    It seems an odd ruling to me. I’d have thought it would make more sense for (2) (the temporary traveller) to continue to be bound by the rules of his home diocese, and for (3) (the vagrant with no fixed abode) to be bound only by the universal rule of Rome. But there is no doubt a good reason.

  26. My Canon Law prof. in seminary made it very clear to us: Canon Law comes up through your feet, meaning, observe the law in that place where you find yourself. I do not think, however, that anyone need question what to do if they are in a diocese that observes something different for their own just for part of one day. So, if you live where the Ascension is transferred to Sunday but take a day trip on Ascension Thursday to a place where it is observed on Thursday you don’t have to attend Mass on Thursday. You’ll be going home that night. However, if you’re staying longer then observe the local laws. One year I was in Canada on vacation from August 10 – 20th. The Assumption is not a day of obligation there. Despite being American I did not attend Mass on the 15th (this was when I was still a layman) because there was no obligation to do so while I was in Canada.

  27. pelerin says:

    Very surprised to learn that the Feast of the Assumption was not a Holyday of Obligation in Canada especially with the French influence there. I presumed it was a universal feast day. How I wish they were standardised. This year the feast day will be on the Monday in France but here in England it has been moved to the Sunday. As I hope to be in France on the Monday I shall be attending Mass there and it would not have occurred to me not to because it was not a holy day in England. I have always understood that ‘when in Rome do as the Romans do’ so it is up to the traveller to find out the dates of holy days in the country they are visiting.

Comments are closed.