title: Can I find total time of 1st time and 2nd time in DATETIME?
body: <p>I would like to find total time of 2 DATETIME. Now I have 2 DATETIMES: loginDT and logoutDT. For loginDT I get from Database and logoutDT is now. like this code below</p>
  
  <pre><code>DateTime loginDT = (DateTime)readerS["login_Date_Time"];
  DateTime logoutDT = DateTime.Now;
  DateTime total = ??????????????
  </code></pre>
  
  <p>How should I do?
  Thanks All</p>