If the approach is polite and organized? As noted above, I understand that asking for last minute availability with someone is a bit rude, so I only do it when I suddenly find myself with unexpected time and availability on my hands, which is rare, but it has happened a few times in recent months.
Ideally, I then reach out to someone I have corresponded with a little bit, but that is not the case if I am out of town. So I make the call, apologize for the fire drill, and see if we can make something happen. I have all my references available, as well as specific times and am prepared to be flexible on location. I understand that I may pay a little extra, and that I better be extra nice, because the lovely person is jumping through hoops for me. And if the answer is no, I say thank you, sorry again, and I hope we can meet another time.
If approached that way, does it make it acceptable?
I also understand that there are ladies who have last minute availability, and may welcome that call, but I cannot quite figure out who they are. And your point, Barbie, about taking the time to get ready and be properly presented does make me wonder a little about those ladies who are ready to go on the spur of the moment. So, perhaps, my sense of urgency when I find myself all dressed up, and all worked up, with nowhere to go, is not at all in my best interest. Big head, tell the little head to heel, boy, heel!
Zig