How to add up join date info into album_pictureview template

[bartek24m]

hello i would like to add up a user join date info somewhere in album_pictureview template

i try to add up $userinfo[joindate] but insted date i can see some figures (1233566287)

i try in this way:
date('d-m-Y', $userinfo[joindate])

in the same template style but without any results :/