Creating Custom 30 days product sales report CSV file and send to admin via email cron in D6

$site_email = variable_get('site_mail', '');

$today_date = mktime(0,0,0,date("m"),date("d"),date("Y"));
"Tomorrow is ".date("Y/m/d", $today_date);
$tomorrow = mktime(0,0,0,date("m"),date("d")-600,date("Y"));
 "Tomorrow is ".date("Y/m/d", $tomorrow);

$sql = "SELECT uc_order_products.order_product_id AS order_product_id, uc_orders.order_id AS uc_orders_order_id, uc_orders.uid AS uc_orders_uid, node.title AS node_title,  uc_orders.order_status AS uc_orders_order_status, uc_orders.primary_email AS uc_orders_primary_email, uc_order_products.qty AS uc_order_products_qty, uc_products.sell_price AS uc_products_sell_price, uc_orders.created AS uc_orders_created FROM uc_order_products uc_order_products LEFT JOIN node node ON uc_order_products.nid = node.nid LEFT JOIN uc_orders uc_orders ON uc_order_products.order_id = uc_orders.order_id LEFT JOIN uc_products uc_products ON uc_order_products.nid = uc_products.nid WHERE (node.type in ('product')) AND (node.status <> 0) ORDER BY uc_orders_created DESC";

$results = db_query($sql); // Run the query
$file_save_path = base_path() . 'sites/default/files/productsale_report_csvs/';

$output = "";
$output.= 'User id,User Name, User Email, User Created Date ';
$output .="
";
$headers = array('Order product ID','Order ID','User Id','Product Title','Order Status','User Email','Quantity','Price($)','Order Created Date');

$filename = 'product_sale_records_'.date('d_m_y_h_i_s').'.csv'; // exit;
$folder_path = $_SERVER['DOCUMENT_ROOT'] . $file_save_path;
$path = $_SERVER['DOCUMENT_ROOT'] . $file_save_path . $filename;

$fp = fopen($path, 'w+');
if ($fp && $results) {
    /*header('Content-Type: text/csv');
    header('Content-Disposition: attachment; filename=' . $filename);
    header('pragma: no-cache');
    header('Expires : 0');*/
    fputcsv($fp, array_values($headers));
    while ($row = db_fetch_array($results)) { // Get the next result, which will/must always be a single field
		$row['uc_orders_created']	=	date('M d, Y', $row['uc_orders_created']);
	    fputcsv($fp, array_values($row));
    }
    fclose($fp);
    $mailto = 'xyz@example.com';
    $from_mail = 'example_demo@demo.com';
    $replyto = '';
    $subject = "product sale reports ";
    $message = "Dear Admin,";
	$message .="
";
    $message .= "Please find the last 30 day product sales reports.";
    mail_attachment($filename, $folder_path, $mailto, $from_mail, $from_name, $replyto, $subject, $message);
	exit;
}

function mail_attachment($filename, $path, $mailto, $from_mail, $from_name, $replyto, $subject, $message) {
    $file = $path.$filename;
	$file_size = filesize($file);
	$handle = fopen($file, "r");
    $content = fread($handle, $file_size);
    fclose($handle);
    $content = chunk_split(base64_encode($content));
    $uid = md5(uniqid(time()));
    $name = basename($file);
    $header = "From: ".$from_name." <".$from_mail.">
";
    $header .= "Reply-To: ".$replyto."
";
    $header .= "MIME-Version: 1.0
";
    $header .= "Content-Type: multipart/mixed; boundary="".$uid.""

";
    $header .= "This is a multi-part message in MIME format.
";
    $header .= "--".$uid."
";
    $header .= "Content-type:text/plain; charset=iso-8859-1
";
    $header .= "Content-Transfer-Encoding: 7bit

";
    $header .= $message."

";
    $header .= "--".$uid."
";
    $header .= "Content-Type: application/octet-stream; name="".$filename.""
"; // use different content types here
    $header .= "Content-Transfer-Encoding: base64
";
    $header .= "Content-Disposition: attachment; filename="".$filename.""

";
    $header .= $content."

";
    $header .= "--".$uid."--";
	 if (mail($mailto, $subject, "", $header)) {
        //echo "mail send ... OK"; // or use booleans here
    } else {
        echo "mail send ... ERROR!";
    }
}