function cn_calendar($categid = '0'){
global $cache, $year, $month, $day, $PHP_SELF, $sql, $config;

//Если категория не указана
if ($categid == '0')
{$cat_cat = $sql->select(array('table' => 'news', 'where' => array('date < '.(time() + $config['date_adjust'] * 60))));}

//Если указана одна категория
elseif (!strpos($categid,',')) 
{$cat_cat = $sql->select(array('table' => 'news', 'where' => array('category ? ['.$categid.']' , 'and', 'date < '.(time() + $config['date_adjust'] * 60))));}

//Если указано несколько категорий
else {
$line = explode(',',$categid);
$cat_cat = $sql->select(array('table' => 'news', 'where' => array('category ? ['.$line[0].']' , 'and', 'date < '.(time() + $config['date_adjust'] * 60))));
    for ($i=1; $i<count($line); $i++) {
    array_push($cat_cat, $sql->select(array('table' => 'news', 'where' => array('category ? ['.$line[$i].']' , 'and', 'date < '.(time() + $config['date_adjust'] * 60)))));
    }

}
    if (!$post_arr = $cache->get('calendar')){
        foreach ($cat_cat as $row){
            $save[] = $row['date'];
        }

        @rsort($save);
        $post_arr = $cache->put(@join("\r\n", $save));
    }

    $post_arr = explode("\r\n", $post_arr);

    $year  = ($year ? $year : $_GET['year']);
    $month = ($month ? $month : $_GET['month']);
    $day   = ($day ? $day : $_GET['day']);

    if ($year and $month){
        $this['month'] = $month;
        $this['year']  = $year;
    } else {
        $this['month'] = date('m', $post_arr[0]);
        $this['year']  = date('Y', $post_arr[0]);
    }

    if (!$calendar = $cache->get(($day ? $day.'.' : '').$this['month'].'.'.$this['year'])){
        foreach ($post_arr as $date){
            if ($this['year'] == date('Y', $date) and $this['month'] == date('m', $date)){
                $events[date('j', $date)] = $date;
            }

            if ($this['month'].$this['year'] != date('mY', $date)){
                $prev_next[] = $date;
            }
        }

        $calendar = $cache->put(calendar($this['month'], $this['year'], $events, $prev_next, $categid));
    }

return $calendar;
}

function calendar($cal_month, $cal_year, $events, $prev_next, $categid){
global $year, $month, $day, $PHP_SELF;

    $first_of_month  = mktime(0, 0, 0, $cal_month, 7, $cal_year);
    $maxdays         = date('t', $first_of_month) + 1; // 28-31
    $cal_day         = 1;
    $weekday         = date('w', $first_of_month); // 0-6

    if (is_array($prev_next)){
        sort($prev_next);

        foreach ($prev_next as $key => $value){
            if ($value < $first_of_month){
                $prev_of_month = $prev_next[$key];
            }
        }

        rsort($prev_next);

        foreach ($prev_next as $key => $value){
            if ($value > $first_of_month){
                $next_of_month = $prev_next[$key];
            }
        }
    }

    if ($prev_of_month){
        $tomonth['prev'] = '<a href="'.cute_get_link(array('date' => $prev_of_month), 'month').($categid != '0' ? '&category='.$categid : '').'" title="'._etc_lang(date('n', $prev_of_month), 'month').date(' Y', $prev_of_month).'">&laquo;</a> ';
    }

    if ($next_of_month){
        $tomonth['next'] = ' <a href="'.cute_get_link(array('date' => $next_of_month), 'month').($categid != '0' ? '&category='.$categid : '').'" title="'._etc_lang(date('n', $next_of_month), 'month').date(' Y', $next_of_month).'">&raquo;</a>';
    }

    $buffer = '<table id="calendar" width="100%" cellpadding="2" cellspacing="0" border="0">
    <tr>
     <td colspan="7" class="menu"><span style="text-transform: uppercase"><b>'.$tomonth['prev'].'<a href="'.cute_get_link(array('date' => $first_of_month), 'month').($categid != '0' ? '&category='.$categid : '').'" title="'._etc_lang(date('n', $first_of_month), 'month').date(' Y', $first_of_month).'">'._etc_lang(date('n', $first_of_month), 'month').' '.$cal_year.$tomonth['next'].'</a></b></span>
    <tr>
     <th class="weekday" style="border-bottom: 1px solid #909090">'._etc_lang(1, 'weekday').'
     <th class="weekday" style="border-bottom: 1px solid #909090">'._etc_lang(2, 'weekday').'
     <th class="weekday" style="border-bottom: 1px solid #909090">'._etc_lang(3, 'weekday').'
     <th class="weekday" style="border-bottom: 1px solid #909090">'._etc_lang(4, 'weekday').'
     <th class="weekday" style="border-bottom: 1px solid #909090">'._etc_lang(5, 'weekday').'
     <th class="weekend" style="border-bottom: 1px solid #909090">'._etc_lang(6, 'weekday').'
     <th class="weekend" style="border-bottom: 1px solid #909090">'._etc_lang(7, 'weekday').'
    <tr>';

    if ($weekday > 0){
        $buffer .= '<td colspan="'.$weekday.'">&nbsp;';
    }

    while ($maxdays > $cal_day){
        if ($weekday == 7){
            $buffer .= '<tr>';
            $weekday = 0;
        }

        # В данный день есть новость
        if ($events[$cal_day]){
            $date['title'] = langdate('l, d M Y', $events[$cal_day]);
            $link = cute_get_link(array('date' => $events[$cal_day]), 'day').($categid != '0' ? '&category='.$categid : '');

            if ($weekday == '5' or $weekday == '6'){ // Если суббота и воскресенье. Слава КПСС!!!
                if ($day == $cal_day){
                    $buffer .= '<td class="weekend"><a href="'.$link.'" title="'.$date['title'].'"><b>'.$cal_day.'</b></a>';
                   } else {
                       $buffer .= '<td class="endday"><a href="'.$link.'" title="'.$date['title'].'">'.$cal_day.'</a>';
                   }
            } else { // Рабочии дни. Вперёд, стахановцы!!!
                if ($day == $cal_day){ // активный
                    $buffer .= '<td class="weekday"><a href="'.$link.'" title="'.$date['title'].'"><b>'.$cal_day.'</b></a>';
                } else {  // пассивный, дурашка
                    $buffer .= '<td class="day"><a href="'.$link.'" title="'.$date['title'].'">'.$cal_day.'</a>';
                }
            }
        } else { // В данный день новостей нет. Хуйовый день...
            if ($weekday == '5' or $weekday == '6'){ // дни, когда по телеку нихуя нет :(
                $buffer .= '<td class="endday">'.$cal_day;
            } else { // работяги хлещат водку после труда
                $buffer .= '<td class="day">'.$cal_day;
            }
        }

        $cal_day++;
        $weekday++;
    }

    if ($weekday != 7){
        $buffer .= '<td colspan="'.(7 - $weekday).'">&nbsp;';
    }

return $buffer.'</table>';
}

echo cn_calendar();

echo cn_calendar('18');

echo cn_calendar('18,19,20');