I'm not an 'active' expert on this anymore because I'm retired now, but I have always thought that a person needs to have a break from work now and then, and especially if you are a good worker, you deserve a reward. We all need to recharge the batteries now and then and it's great to be able to do something enjoyable and special. It isn't good if you abuse the privilege.
You shouldn't have to be in a position for your employer to make you feel guilty about taking some days off of work, and especially when they get advance notice so they can prepare for it.
The year before I retired, my manager was unhappy with me because I took time off for two short surgeries. In August I needed to have my gall bladder removed (the short version, not the long one) and then in October, I injured my knee and had to have arthroscopic surgery. He said 'well, I certainly expect that this will take care of your problems, won't it?' I said sure, unless I have another injury or illness. And by the way, I'll be taking my last two weeks of vacation at the end of December. I think he thought I should forfeit my vacation time, but fortunately, the company didn't have any such rule.
I may not have injured my knee on 'company time' but I'm very sure that my gall bladder went bad while I was working. lol
just my opinion