title: Convert month string to int format
body: <p>I have the following string "Dec".</p>
  
  <p>How can I convert this string to the month number 12?</p>
  
  <p>I tried this:</p>
  
  <pre><code>DateTime.ParseExact("Dec", "MMMM", null).Month
  </code></pre>
  
  <p>This doesn't work.</p>