I'm gonna ask a grocery store employee if he had Friday off. Is that nosy of me?
Why would it matter if he had Friday off?
Genuine curiosity.
I don't think that is a good idea. You should not be nosy about a stranger's business. It doesn't concern you want his schedule is and you shouldn't pry into his life.
He's a cashier, it's his job to answer questions like this
No, it's not his job to answer questions like that, nor is it your business. Just grocery shop and don't pry into his life.