[quote="Red_Meg, post:5, topic:242115"]
I'm not sure how "authoritative" an answer you need... Betsy is a cooperator of Opus Dei, IIRC, and a long-standing source of very good, reliable information about the Work here on CAF.
I'm a supernumerary who posts far less frequently, and I can say that you do your best with daily Mass. I know there have been instances when a daily Saturday Mass was not an option (ie just not offered in the vicinity) for a particular member of the Work, so attendance at both Saturday evening vigil and Sunday morning Mass was done instead. Back in my college days when the Saturday vigil was my Sunday Mass of choice (I was in charge of the music for that Mass) that normally meant for me Saturday morning Mass, then Saturday evening Mass.
That being said, back to Utopia's original query about "breach of contract"-- the norms of piety we promise (not vow!) to follow in Opus Dei are not binding under pain of sin. We don't have the same weight of obligation a vowed religious does. We do it because we want to, not because we have to. And during those times when the "other" demands of my vocation (i.e. nine children) prevent me from attending Mass on a given day, I've been advised in confession to simply offer it up and make a spiritual communion during the time I would have attended Mass had I been able. There aren't "plan of life police" walking around monitoring us.
Hope this helps? I'll try to pop back in later and check for replies but it may be a while...
My point is that if you have a question about Opus Dei then you should ask Opus Dei. Just as if you have a question about an order or diocese you should ask them.
I do not understand why someone who has a question about a specific group and how they do things would ask that question in an anonymous internet forum. Doing so does not really get you an answer, it gets you the opinion of those who respond.