I think they're talking about holidays. Like Thanksgiving, Christmas, etc. Pretty much every US company does this.
Lately I've seen a lot of 'unlimited' - read as less than your boss takes
In Europe 20 is the legal minimum
I took a job with "unlimited vacation" at one company and then AFTER I started my boss "explained" to me that "Unlimited means 4 weeks here." About two months after I started I was moved to a different team new boss. My new boss (same company) had clear deliverables and said, "Unlimited means Unlimited so long as you hit your deliverables." Glad I was moved to a new team.