title: How to count unique values in Excel with two conditions
body: <p>I know there is already a question that has been answered about counting uniques with a condition (<a href="https://stackoverflow.com/questions/15944249/excel-count-unique-values-with-a-condition">Count Unique values with a condition</a>), but I want to know how to count uniques in a column with TWO conditions.</p>
  
  <p>I have a dataset with dates of locations created as well as city. Each location has an owner and sometimes an owner can have multiple locations so I want to count unique owners by city and month (both already exist as columns).</p>
  
  <p>How can I do this?</p>