Finally, you can afford to spend up to 4 weeks per year without worrying about your presence at the business. You do not need to have a bad consciousness anymore when you take time off (whether you call it a small-scale sabbatical like seanwes does or time to travel and study the world like I prefer to do).
Step 1: Your calendar
Watch your calendar for a whole year.

What do you see? Obviously, 12 months with more or less 30 days. How many weeks are there per year? That is a bit harder. Ok, it is 52. That is it. You uncovered it already.