change parent of a page inside a reference field inside a repeater field

[froot]

Inside a Repeater field I have a page reference field. The pages that I select here have a date. I basically want to change the parent (send to the archive) when the date ist older (smaller) than today.
Long story short, I managed to change the parent of the referenced page alright. Also seemingly managed to remove it from the selected items in the page reference field. I can not however save the page for some reason, don't know what I'm doing wrong, the selected pages stay the same in the admin backend.

Here's my code

// this just won't save the changes
$organize = function() use($pages, $page) {
    $reps = $page->reps->find("type=posts_rep"); // the type of repeater items in question
    foreach ($reps as $rep) :
        foreach ($rep->posts as $post) : // loop through the selected referred pages
            $d = date('Ymd', $post->getUnformatted('post_date'));
            $j = date('Ymd');
            if ($d < $j) :
                $page->of(false);
                $rep->posts->remove($post);
                $page->save(); // pass an argument? which one?
                $page->of(true);
            endif;
        endforeach;
    endforeach;
    
    $posts = $pages->find('template=post');
    $today = date('Ymd');
    $archive = $pages->get("id=1075");

// this following part works fine
    foreach ($posts as $post) :
        $post_date = date('Ymd', $post->getUnformatted('post_date'));
        $p = $post->parent;
        $pp = $p->parent;
        if ($post_date < $today && $pp != $archive) :
            $post->of(false);
            $np = $archive->child("title=$p->title");
            $post->parent = $np;
            $post->save();
            $post->of(true);
        endif;
    endforeach;    
};

$organize();

and while I'm at it, I ultimately want to turn this into a cronjob of some sort. Would Lazycron be an option? How would that work, something like: 

$organize->everyDay(86400); // can't be that easy, can it

 

[froot]

[SOLVED] OK so apparently I need to do $rep->save(); instead of $page->save(); which is kind of weird, I thought I had to always save the page where the field is on.