Rearranging posts based on categories

Hey everyone on Stackexchange!

I’m trying to find a way to prioritize posts based on a category in a loop, which is sorted by dates. All posts are grouped under their respective dates. The date labels appear once on top of posts of the same date like this:

Date

• Post1
• Post2
• Post3

Date before that

• Post 4
• Post 5

etc

I’m trying to achieve a result, where if a post belongs to a certain predetermined category (I would only be using 1 category), it would be moved above others under a date as such:

Date

• Post3 (special category)
• Post1
• Post2

Date before that

• etc

I’ve done research for a while on this topic and I can’t figure out whether this would even be possible or not. Some query functions seem to serve a similar purpose, but I’m not certain and the date sorting makes it harder to figure out. Would I need multiple loops or something of that nature?

My loop: http://pastebin.com/Pp0rA5j7

The loop and the sorting mechanism look like this in general (pastebin for a full code):

<?php $w_h = $w_d = $last = 0; ?>

<?php if (have_posts()) : while (have_posts()) : the_post(); ?>

    <?php
    if ( date('Yz') == get_the_time('Yz') ) {
        if (!$w_d++) echo '<h6>Today</h6>';
    } elseif ( date('Yz')-1 == get_the_time('Yz') ) {
        if (!$w_h++) echo '<h6>Yesterday</h6>';
    } else {
        echo the_date('', '<h3>', '</h3>');
    }; ?>

// post content

    <?php endwhile; ?>
    <?php endif; ?>
                     <?php else : ?>

Sample site: http://goldenred.web44.net (I would like to move the post test 6 with the category “test” above others under February 3, 2013)

I would be extremely thankful if anyone more experienced could help or at least point me towards a general direction. All comments are welcome.

May be it’s a bad idea, but it’s the only.

Don’t print posts immediately, but collect them in different variables: one for category “test”, one for the rest.

<?php
$w_h = $w_d = $last = 0;
// init variables to concatenate content later
$primary_posts = $secondary_posts="";
// empty array to fill later
$category_names = array();
if (have_posts()) :
    while (have_posts()) :
        the_post();
        if ( date('Yz') == get_the_time('Yz') ) {
            if (!$w_d++) echo '<h6>Today</h6>';
        } elseif ( date('Yz')-1 == get_the_time('Yz') ) {
            if (!$w_h++) echo '<h6>Yesterday</h6>';
        } else {
            echo the_date('', '<h3>', '</h3>');
        };
        // get post categories
        $category_objects = get_the_category();
        foreach($category_objects as $category_object) {
            $category_names[] = $category_object->name;
        }
        // if posts belongs to category 'test'
        if( in_array('test', $category_names) ) {
            $primary_posts .= '<div class="post">Post of category "test"';
            // title, categories and excerpt goes here
            $primary_posts .= '</div><!-- .post -->';
        }
        else {
            $secondary_posts .= '<div class="post">Post of category other than "test"';
             // title, categories and excerpt goes here
            $secondary_posts .= '</div><!-- .post -->';
       }

    endwhile;
    // output all posts of category "test"
    echo $primary_posts;
    // output all posts of category other than "test"
    echo $secondary_posts;
endif;