You have some PTO that you're going to lose if you don't use it soon. When figuring out which days to pick for a random PTO day just to use it up, do you:
A. Pick the days that would be the least impacted by your day off
B. Pick the day that would get you the biggest bang for your buck. The days that seem to have the most bullshit, the heaviest work load, etc. You will get out of the hard work for that day but your absence might impact the productivity of the day or effect your co-workers work day.