You could do some replacing with arrays.
$days = array("mon","tue","wed","thu","fri","sat","sun");
$months = array("jan","feb","mar"); //etc
$day = date("w");
$month = date("n");
$numday = date("j");
$day = $days['$day'];
$month = $months['$month'];
echo "$day, $months $numday";
There probably is some other way, setting some local setting or something, but I don't know.