a function i can't understand in php
<pre><code>for ($y = 25; $y &gt;= 7; $y--)
{
    $showYear = false;
    for ($m = 12; $m &gt;= 1; $m--)
    {
        if (blogList($m, $y))
            $showYear = true;
    }
    if ($showYear) {
        echo '&lt;h2&gt;' . (2000 + $y) . '&lt;/h2&gt;';
        for ($m = 12; $m &gt;= 1; $m--)
        {
            echo blogList($m, $y);
        }
    }
}

//blog archives

function blogList($month, $year) 
{
    $lastDate = array(31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);

    $beginDate = mkTime(0, 0, 0, $month, 1, $year);
    $endDate = mkTime(0, 0, 0, $month, $lastDate[$month - 1], $year);


    $query = .......;
}
</code></pre>

<ol>
<li>i don't know why he set the <code>$y=25</code>.<code>$showYear = false;</code></li>
<li>why the <code>$lastDate = array(31,29,31,30,31,30,31,31,30,31,30,31);</code>?</li>
</ol>
