<?php
function birthday ($birthday){
list($year,$month,$day) = explode("-",$birthday);
$year_diff = date("Y") - $year;
$month_diff = date("m") - $month;
$day_diff = date("d") - $day;
if ($day_diff < 0 || $month_diff < 0)
$year_diff--;
return $year_diff;
}
echo birthday ("1991-08-01");
?>
<?php
echo date("Y-m-d");
?>