From a reader:
I plan a trip to New Zealand to attend a conference. Current travel plans call for leaving LAX Saturday evening. The flight crosses the international date line, and so it lands in Auckland on Monday morning. What becomes of my Sunday obligation? (Attending a Saturday vigil Mass, I suspect. will be impractical, as I’ll be flying into LA from the east coast.)
I’m sure the question must have come up before; is there any authoritative answer?
If there is no Mass where you are on a day of precept, and you are there for a good reason and not to avoid going to Mass, then you cannot fulfill the obligation. If you cannot do it, because it is not possible, then you are not culpable for not not fulfilling the obligation.
This would apply also to astronauts on the International Space Station. I am not sure you can even tell, easily, what day it is there, since it is moving across the date line often during a terran day. Unless, perhaps, they are working from, say, UTC? Even then, unless they have a chaplain aboard, they can’t go to Mass.
Which of course raises the issue of how to follow the rubric about the priest raising his eyes heavenward,… not to mention the pouring of wine and water, etc. But I digress.
If you can’t get to Mass, really, then you haven’t committed a sin.