title: Issue with DATEADD function in DAX
body: <p>I recently started learning DAX. I am unable to understand <code>DATEADD</code> function properly. The below expression is giving error.</p>
  <pre><code>DATEADD(FIRSTNONBLANK(DATATABLE(&quot;TodaysDate&quot;,DATETIME,{{&quot;9/24/2016&quot;}}),TRUE()),4,MONTH)
  </code></pre>
  <blockquote>
  <p>A table expression containing more than one column was specified in the call to function 'DATEADD'. This is not supported.</p>
  </blockquote>
  <p>But it's working with <code>EDATE</code></p>
  <pre><code>EDATE(FIRSTNONBLANK(DATATABLE(&quot;TodaysDate&quot;,DATETIME,{{&quot;9/24/2016&quot;}}),TRUE()),4)
  </code></pre>
  <p>and <code>FIRSTDATE</code> is not working like <code>FIRSTNONBLANK</code>. Is there a problem with <code>DATATABLE</code> usage?</p>
  <pre><code>FIRSTDATE(DATATABLE(&quot;Today1&quot;,DATETIME,{{&quot;9/24/2016&quot;}}))
  </code></pre>
  <blockquote>
  <p>A table expression containing more than one column was specified in the call to function 'FIRSTDATE'. This is not supported.</p>
  </blockquote>