title: Perform string to date manipulation inside SSIS package with logical operators
body: <p>There are 2 string columns on an inbound file, both formatted YYYYMMDD.</p>
  
  <p>If column 1 is after 10/1/2015, add 90 days to the column 1 date and load in column 2.  The data needs to be loaded in the system as YYYYMMDD string (so convert it back).</p>
  
  <p>I'm trying to set up a Dervied Column module to do this, but I haven't been having much luck.</p>
  
  <p>Here's what I have so far:</p>
  
  <p><code>[Column 1] &gt;= (DT_DATE)"2015-10-01" ? DATEADD("dd",90,[Column 1])</code></p>
  
  <p>Please help.</p>