title: SAS PROC SQL - How to add months to a date
body: <p>How can I add months to a date?
  I've tried the function <code>ADD_MONTHS(&lt;my date&gt;, 6)</code> and <code>DATEADD(Month, 6, &lt;my date&gt;)</code> but both functions are not recognized.</p>
  
  <p>What's the correct function to use?</p>