title: SSRS datepart #error in report
body: <p>I am trying to set a simple expression in SSRS in my report using the <strong>datepart</strong> function:</p>
  
  <pre><code>=datepart("dw",Fields!period_dt.Value)
  </code></pre>
  
  <p>When I preview the report, the values come up as #error.</p>
  
  <p>Am I missing something completely obvious here?</p>
  
  <p>The <strong>Fields!period_dt.Value</strong> field contains dates in this format 12/31/2013 12:00:00 </p>