title: Plus 2 date in SQL
body: <p>I really need help on this those function DATEDIFF OR DateAdd , because I have no idea on those things.</p>
  
  <pre><code>Declare @EstDate as Date,
          @Shipdate as Date,
          @Workingday as Int,
  </code></pre>
  
  <p>I need to do like this:</p>
  
  <pre><code>@EstDate(Date) = @ShipDate(DATE) - @WorkingDay(int) - 2days
  </code></pre>
  
  <p>Example: @EstDate(date) = '6/11/2011' - 5days - 2days.</p>
  
  <p>How can I do this formula in SQL ? >_&lt; In PHP its easy, but in SQL 2000 up, I have no ideas.</p>