CuriousInIL:
Ok—A very technical question. At what point in the mass can one leave and still have fulfilled the Sunday obligation? Does it matter if you are not in a state of grace and therefore will not be receiving?
I understand that the preference is to remain until the last note of the recessional song (and sing along). And, I am not talking about a person that would do this every week. This is about a very rare event. I have found many opinions on being late to mass; but, I have not seen the same on leaving mass early.
So, there is the question—as I said a very technical one in the sense of looking for a “rule” and not a discussion of best practices or feelings about those who consistently arrive late or leave early.
You are obligated to go to Mass on all Sundays and Holy Days of Obligation- whether you’re in a state of grace or not (but your reason should NOT be “because I have to”- I somehow doubt the obligation is fulfilled if that is the reason), and not be concerned about how long you have to stay to meet the obligation. If you go long enough with the mindset that all you’re doing is meeting an obligation, then it’s meaningless- as following rules simply for the sake of the rules is meaningless.
Ideally, you should get there before Mass starts to focus on what you’re about to do, and stay awhile after it ends, to reflect on what you just did. I understand life is not ideal- sometimes that just doesn’t happen- if you get there as soon as you possibly can, and stay until it’s over if at all possible- then you’re fine. If you’re late because of carelessness, or you are so late you cannot focus on the Mass, or if you run out to your car before communion to beat the rush, or right after communion as if to say “well, that’s over with- time to go eat”, I doubt the obligation is met. Going to Mass is about your relationship with God. How would you like it if you met a friend for dinner, they got there late, then left as soon as they were done eating without really taking time to talk to you? That’s how it is when you go to Mass late and/or leave early.
Remember- many Protestants go to church for 2 1/2 hours on Sunday mornings, often an hour on Sunday nights, sometimes an hour on Wednesday nights, and some go to things such as bible studies *at least *one other night a week- and their lives are just as busy- if not more so- as Catholics’ lives.
You mention this is a rare event- I wouldn’t worry about it. If you cannot help it, it’s not your fault. If possible, find another Mass to go to- so you can focus better, but if what causes this is beyond your control, then I wouldn’t worry about it.