Some 20 years ago, I worked at a small company as their first employee. Salaried, and I worked lots of unpaid overtime as needed. After working there for almost a year, my boss came to me with a complaint. He said that he was only giving me ten paid days off per year, and that this number included not only sick days and vacation days, but also federal holidays when the office and our clients were closed and I couldn't work. And I was over 10 days off so far.
I was shocked. I pointed out that I didn't have the option to work those days, but that didn't matter to him. I then said that I was working multiple Saturdays and Sundays, so my “day's off” were comp time. And then I got out of there for a better job as fast as I possibly could.