Is it legal for an employer to ask why you are taking time off from work?

It is not illegal for me to ask, it is illegal for me to ask with conditions. You come to me and say “hey I need Tuesday and Wednesday off next week." I have mostly good relationships with my staff. I say “sure no problem I can cover it by then”. Here is where I LOVE PTO. It makes no difference why you take off whatsoever. I can ask why you are needing the days, and you can choose to respond or not. Most of my employees just tell me they have family functions, or they need a doctor visit, or some family related things. Some just say they want to relax at home. All perfectly fine I could care less really. If they choose not to say anything, or they say it's personal, that is perfectly fine too. Usually I don't really have to ask they tell me.

Where it gets illegal is if I were to say “well lazing around the house is not acceptable, so your time off is rejected". Or another example is if you said it was personal, and I said well you better tell me or you are fired! That would be illegal.

Our company is extremely lax when it comes to time off. That is why, for us, it is so much easier to accrue PTO hours. If you are sick and need a day off, take your PTO. Just please let me know as soon as you possibly can so I can get your spot covered. What really makes me angry are those who choose to call me ten minutes before their shift and say they decided to take some PTO. You have no idea how stressful that makes my day! My workload just doubled, my stress levels just exploded. All because you could not make your mind up fast enough. The act of doing this several times will get you legally fired, the reason for doing it makes no difference to me.

Scoop: Nike names Michael Gonda as chief communications officer - Axios

As I stated above, the reason for you taking time off is irrelevant to me. As long as it was done by the rules, mostly that you give me 24hr notice and it does not fall on every holiday (just like everyone else you need to work one or two holidays a year). I had someone come in and say they saw an employee partying it up at a concert, and that is why they called out sick. I simply said I didn't care WHY they called out, only that they let me know more than 24hours before their shift and I was able to cover the spot. That shuts down the rumor and gossip rather easily. Did I mention I love the PTO system??