title: SSRS: [BC30455] Argument not specified for parameter 'DateValue' of 'Public Function Day(DateValue As Date) As Integer'
body: <p>I'm trying to calculate the difference between two days using DATEDIFF (). I use following code for this:</p>
  
  <pre><code>=DATEDIFF(DAY,CDate(Fields!Eingang_Kundenanfrage.Value),CDate(Fields!Ausgang_Angebot.Value))
  </code></pre>
  
  <p>Every time I try to save the report, I get this error message:</p>
  
  <pre><code>[BC30455] Argument not specified for parameter 'DateValue' of 'Public Function Day(DateValue As Date) As Integer'.
  </code></pre>
  
  <p>The DataSource is a SharePoint List and the Date is given in the following format: 23.05.2014 00:00:00 (DD.MM.YYYY HH:MM:SS).</p>
  
  <p>I've googled for a working solution for a long time now, but I had no success.</p>
  
  <p>Is there someone who can help me?</p>