- print_r: documentation ( source)
- date_default_timezone_set: documentation ( source)
<?php
date_default_timezone_set('America/Sao_Paulo');
$d1=new DateTime("2012-07-08 11:14:15.638276");
$d2=new DateTime("2012-07-08 11:14:15.889342");
$diff=$d2->diff($d1);
print_r( $diff ) ;