Hey Jan,

Unfortunately if you use this function getFieldValue, it actually only display user birthday date instead of show their age directly, you can try to use my following suggestion code re-compute the age again.

$id = JRequest::getInt( 'id' , null );



// current user profile id

$my = Foundry::user($id); 



// Get your current birthday custom field unique key e.g. BIRTHDAY

$birthdayDate = $my->getFieldValue('BIRTHDAY');



// Pass birthday date into this section

$birthDate = new DateTime($birthdayDate);

$now = new DateTime();



// Use this formula generate to age

$age = floor(($now->format('U') - $birthDate->format('U')) / (60*60*24*365));

echo $age; // Result

By the way, I am really sorry but unfortunately our support policy does not cover customizations Hope you understand.