Heck ya!! I used to work for a big company and it was some what encouraged to take your two personal days a year. I loved a surpise day off especially when you are not sick and can actually do stuff. I work for a small family company now so no time off unless you have a vacation scheduled or are in the hosiptal (not joking, if you are real sick, there is a couch in the office to lay down on but you still have to come in).
Enjoy your day!!!