<?php
$dob = "30/08/2002";
$a = explode('/',$dob);
$selection = 1;
switch ($selection){
case 1:
$b = mktime(0, 0, 0, date($a[1]), date($a[0]), date($a[2])+8);
echo date('d/m/Y',$b);
break;
case 2:
$b = mktime(0, 0, 0, date($a[1])+6, date($a[0]), date($a[2])+10);
echo date('d/m/Y',$b);
break;
case 3:
$b = mktime(0, 0, 0, date($a[1]), date($a[0]), date($a[2])+2);
echo date('d/m/Y',$b);
break;
}
You should have a default value for the switch statement, but I'll leave that to you,