You have to do the math.
Say 10 candidates with the skills required, then whittle that down to 5 maybe 6 who have been asked for interview.
So the hiring managers read 10 CV’s, some of them will have been structured enough with summaries and key bulleted skills required and targeted/aligned to the role, some of them will just be a 5-7 page wordy mess with waffle and embellishment.
So the hiring managers read all that, give them an hour max to read them, if they are busy they’ll have read the first line of each role you have done. They’ll have contacted HR or whomever to arrange interviews, another hour or two depending on the level of crap they have to deal with. Then HR’s given feed back as to when theres a free diary and the managers made the decision to do all this in the shortest time possible, so a day maybe 2. After all, all the information on the candidates got through the first hurdle.
On the basis that an interview takes 1hr each, to thats 3 in a morning, 2/3 in an afternoon. So that one whole day devoted to listening and quizzing from/to the candidate, cost wise this is an expensive day already.
Your chances of re-aranging are slim to the point of non existent prior to the interview, call in on the day and you maybe lucky in that the hiring managers “got an hour back to do something else” and happy, or pissed off that you can’t attend.
Nobody knows what the hiring managers thinking feeling on the day, or beforehand, so you have to make sure you attend to at least be in with a chance.