- abs: documentation ( source)
- floor: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
$date = "2014-11-29";
$today = date('Y-m-d');
echo $today;
$diff = abs(strtotime($date) - strtotime($today));
$days = floor($diff /3600/24);
echo $days;