Mental health days, needed to take a short trip. PTO is for personal time off; I never even give a reason for why I'm calling-in. I just make sure to give at least a 4-hour heads-up (though the policy is 3 hours before it's considered "unexcused") as a professional courtesy. Other than that, those are my days to use as I see fit.

Now if I have something planned ahead of time, of course I'll let them know way in advance. But sometimes shit pops up and the PTO is mine to use as needed. But that's just how I feel about it