title: Subtracting timestamp in oracle returning weird data
body: <p>I'm trying to subtract two dates and expecting some floating values return. But what I got in return is as below:</p>
  
  <pre><code>+000000000 00:00:07.225000
  </code></pre>
  
  <p>Multiplying the value by 86400 (I want to get the difference in second) is getting something even more strange value being returned:</p>
  
  <pre><code>+000000007 05:24:00.000000000
  </code></pre>
  
  <p>any idea? I'm suspecting is has something to do with type casting.</p>