Php 如何在 Woocommerce 中自动删除旧的已完成订单

我需要将WooCommerce设置为自动清理旧的已完成订单.搬到垃圾桶是可以的，但我真的更愿意把它们删除.以下是我现在使用的方法，但似乎不起作用:

function expire_after_x_days(){
        global $wpdb;
    // Get current time
        $today = date("mdy");

    // set time to expire
        $time_to_expire = "-180 days";
        $expiration_date = date("mdy", strtotime( $today . $time_to_expire));

    // Get orders with processing status
        $result = $wpdb->get_results("SELECT * FROM $wpdb->posts WHERE post_type = 'shop_order' AND post_status = 'wc-completed'");

        if( !empty($result)) foreach ($result as $order){
            // Get order's time
            $order_time = get_the_time('mdy', $order->ID );

    // Compare order's time with current time -10 days
        if ( $order_time < $expiration_date ){

    // Update order status    
               wp_delete_post($order_id,true);
            }
        }
} 

    // Use the best HOOK for your case 
    add_action( 'admin_footer', 'expire_after_x_days' );

    // OR simply call the function if you are pasting this in your functions.php 

我做错了什么？

function expire_after_x_days(){
        global $wpdb;
    // Get current time
        $today = date("mdy");

    // set time to expire
        $time_to_expire = "-180 days";
        $expiration_date = date("mdy", strtotime( $today . $time_to_expire));

    // Get orders with processing status
        $result = $wpdb->get_results("SELECT * FROM $wpdb->posts WHERE post_type = 'shop_order' AND post_status = 'wc-completed'");

        if( !empty($result)) foreach ($result as $order){
            // Get order's time
            $order_time = get_the_time('mdy', $order->ID );

    // Compare order's time with current time -10 days
        if ( $order_time < $expiration_date ){

    // Update order status    
               wp_delete_post($order_id,true);
            }
        }
} 

    // Use the best HOOK for your case 
    add_action( 'admin_footer', 'expire_after_x_days' );

    // OR simply call the function if you are pasting this in your functions.php 

我做错了什么？