Thank you very much for your nice support!
Then I`ll wait for your snippet :-D

Have a nice weekend, Hermann

Hi, Hermann.

Here it is:

<?php $cuser = CFactory::getUser($row->user->id);
$birthDate = $cuser->getInfo('FIELD_BIRTHDATE');
$yearOnly = date("Y", strtotime($birthDate));
echo $yearOnly;
?>

You don't have to declare $cuser = CFactory::getUser($row->user->id); if you already did that.
Code displays year only from field FIELD_BIRTHDATE.
You may change field name to different one but field needs to use calendar/birthdate.