I THINK you might be referring to how Market Force uses the terminology "report available" when you most definitely have an assigned date you picked and which also shows. If this is what you mean, no, you don't pick any day up through your assigned date. You would need to click to reschedule if you want to go on a different day.
There are shops out there with a due date and that allow you to go when the business is open, at your convenience, just get it done by the due date. You often don't pick a date at all for those but some will have you give the date you intend to go with room for adjusting for things like needing to schedule an appointment. For those, yeah, you do get to pick and you may not need to communicate changes unless something unusual happens. I had one with a two week window and they contacted me when I didn't go the first week just to be sure I was committed. They didn't want to miss a deadline and I was new to them, it made complete sense the.scheduler got nervous.