title: strtotime() doesn't return false
body: <p><code>strtotime(" ")</code> doesn't return false when I provide string containing just space or any other character.</p>
  
  <p>Are there any less code solutions to make it return false?</p>
  
  <p>I can't use <code>preg_match</code>, because date formats are all different depending on locale of each user.</p>
  
  <p><a href="http://php.net/manual/en/function.strtotime.php" rel="nofollow">http://php.net/manual/en/function.strtotime.php</a></p>
  
  <blockquote>
    <p>Returns a timestamp on success, FALSE otherwise. Previous to PHP
    5.1.0, this function would return -1 on failure.</p>
  </blockquote>
  
  <p><strong>Edit: I need to validate the date string, not to trim spaces or other user-provided characters.</strong></p>