Unlimited vacation is in no way the same thing as 6 weeks of actual vacation. Look into it a bit more. You'll see that unlimited vacation is really just a scam. In your case it's worked out. Actual vacation days are tracked and part of your salary. For example, if you leave, you are entitled to the wages of your remaining untaken vacation days. Unlimited vacation is a favor that your manager is granting. The company is not obligated to grant your request. You have no legal right to take the days off as you do with real vacation.