Calculate the Days between 2 dates

<?php
// >= 5.4
$date1 = new DateTime('2013-02-05');
$date2 = new DateTime('2013-03-05');

$interval = $date1->diff($date2);
 
// Suppose you only want to display the days
printf("difference %d days <br>",$interval->days);



// bis 5.3
$date1 = '2013-02-05';
$date2 = '2013-03-05';

$diff = abs(strtotime($date2) - strtotime($date1));

$years = floor($diff / (365*60*60*24));
$months = floor(($diff - $years * 365*60*60*24) / (30*60*60*24));
$days = floor(($diff - $years * 365*60*60*24 - $months*30*60*60*24)/ (60*60*24));

printf(" %d days<br>",  $days);
?>