title: Created_at or updated_at not displaying full dateTime
body: <p>In my laravel app i need to compare 2 dateTime, the created_at and the updated_at, but i notice that when i call this properties of the record is not disaplayed the seconds, onlu hour and minutes, i need to get the seconds, what i need to change or include to show all info? I beend checking on the documentation and didnt found anything.</p>
  
  <p>Ex:</p>
  
  <pre><code>$calculation-&gt;created_at
  </code></pre>
  
  <p>output:</p>
  
  <pre><code>2017-03-03 21:03
  </code></pre>
  
  <p>And in database is:</p>
  
  <pre><code>2017-03-03 21:03:22
  </code></pre>