<?php

// Set how old you "are"
$age = 21;

date_default_timezone_set('America/New_York');
$age_offset = 31556926 * $age;

$current_date = time();
$birth_date = strftime('%m/%d/%Y', $current_date -  $age_offset);

echo "Hai I'm soooo $age only. Born on $birth_date and everything!";
# echo $birth_date; // Short, sweet, and to the point

?>