First, some background:
I go to confession only to parishes with long lines, because at those parishes confession is valued, both by the priests and by the parishioners. I know it’s valued because it’s available often and it’s used often. For me, waiting in line is part of the sacrament. I think it’s beautiful. It’s an enormous opportunity to experience being part of a community of sinners – all of us waiting together for forgiveness. This is very powerful. There’s almost a Final Judgment feel about it: awaiting our Messiah, all together.
In practical terms it is also a wonderful part of the penance: Having to wait, and having more time to reflect on our sins (and perhaps think of some more serious areas we haven’t worked on!).
I don’t want anyone to be timed or rushed – not my fellow penitents, not me. This is why I think it’s an extremely bad idea to schedule confessions only before Saturday Vigil Mass. (3:30 - 4:30, or worse in some cases I have seen, 4-4:30)
Second, the OP’s concern:
It sounds as if the OP is not in a parish with frequent confession and thus many options.
I agree with others that the priest should be made aware of what’s going on. Canon law provides for anonymous confessions, so no penitent should be made to feel he or she must make a private appointment, off-schedule. It it were I, I would send the priest a note about this frequent occurrence, noting what you have here, about your own promptness & patience.
Here is the solution, everybody – a solution which has been demonstrated to work.
For the singular priest in a parish, do what one of our locals does: ***Schedule Confessions Saturday morning, after the Sat. a.m. Mass. *** Saturdays and Sundays are normally a priest’s heaviest work days. Is he out running errands and having a day off on Saturday? Hardly. He’s ministering to his flock in most cases, most of the weekend. If he says Mass Saturday morning, he has to be there physically in church. Unless he has an even more urgent requirement every Saturday morning, involving administering the sacraments, Saturday morning confession time is merely one part of a Sacrament-heavy weekend. Broadly there should a “window,” but it means that if the “end” of the time is 9:30 or 10, no one will be turned away if someone else has taken very long.
In parishes of more than one priest, this is a no-brainer, and also works, every time: The priest saying Mass is not the priest hearing Confessions. No time limit, therefore. Confessions begin before Mass (weekdays and weekends, by the way, including Saturday afternoons), and continue until the last penitent is heard. The priest just waits in the confessional until no one shows up for quite a long period of time. This means that he’s usually there way before Mass plus deep into Mass.
There are 3 parishes in my region which do this, and it’s beautiful and powerful. Nothing dramatizes the redemption dynamic as much as having Penance and Eucharist simultaneously occurring, with long lines. I’m grateful for the enlightened priests who run these parishes, and I refuse to go anywhere else locally for confession.