title: How to get TimeSpan from DateTime
body: <p>Scenario:</p>
  
  <p>Third party web service returns <code>datetime</code> in two separate fields i.e. date and time. I need a way to concatenate into single field.</p>
  
  <pre><code>e.g.
  
   startDate='24-06-2012'
   startTime='1-01-1970 1:00:00 AM'
  
  Expected result:
   fullStartDateTime='24-06-2012 1:00:00 AM'
  </code></pre>
  
  <p>I tried to get the TimeSpan part from startTime and got no where. Could someone let me know if there's a smart way to achieve above.</p>