I gave a months notice, what more could you ask for?

I am an old man. I have been with this company for quite a few years. Today I asked permission to take a single day of PTO over a month in advance (laughable) and was asked to provide additional information as to WHY I need this day off. Why does my employer need this information? Why do I owe anyone an explanation on why or how I choose to use my EARNED PTO? I can’t help but feel any information I provide would be used against me…