Good question.
At my store we have the issue where some managers will okay/deny anything as soon as it comes up and others who wait to the last possible minute. There is one assistant and our store mgr. that if they look at the dates put in will deny them no matter who you are, and even if you have spoken to someone about the dates. They do this to everyone.
I have had it where my dates have been approved almost as quickly as i put them in, and other times not knowing if they approved/denied it until about a week before, and some that they never looked at and dind't get a yes or a no and so the schedule was put up and i was working that day or already scheduled off. Once they scheduled me for a day i had asked for to go to the doctor. They had never approved/denied it in the system. I went straight to an assistant and told thme i had asked for it off about a month before and no one had ever approved/denied and i wasnt' going to be here on that day, so just a heads up. He went ahead and took care of it, and apologized.