- time: documentation ( source)
- floor: documentation ( source)
- strtotime: documentation ( source)
<?php
$now = time();
$date = strtotime('2014-05-01');
$total_days = floor(($now - $date)/60/60/24);
$weeks = floor($total_days/7);
$days = $total_days % 7;
echo $weeks . ' weeks and ' . $days . ' days ago';