title: Laravel 4: Validate start and end date with before and after validation
body: <p>I want to validate two date fields in a form which is from_date and end_date. Need to check from_date is less than end_date.</p>
  
  <pre><code>$rules = array('from_date' =&gt; array('sometimes','date_format:"Y-m-d"', 'before:'.Input::get('to_date') ),
                          'to_date' =&gt; array('sometimes','date_format:"Y-m-d"', 'after:'.Input::get('from_date') ) );
  </code></pre>
  
  <p>This is what i tried. But that does not work. If i give the to_date as empty value it will through the error. </p>