total_sales保存了所有时间的总销售计数，因此您需要编写自定义查询来获取特定日期之间的销售计数。

//woocommerce get total sale count of a product after a specific data
function wh_get_total_sold_by_product_id($date_from, $product_id)
{
    global $wpdb;
    $date_to = date('Y-m-d');

    $sql = "
    SELECT COUNT(*) AS sale_count
    FROM {$wpdb->prefix}woocommerce_order_items AS order_items
    INNER JOIN {$wpdb->prefix}woocommerce_order_itemmeta AS order_meta ON order_items.order_item_id = order_meta.order_item_id
    INNER JOIN {$wpdb->posts} AS posts ON order_meta.meta_value = posts.ID
    WHERE order_items.order_item_type = 'line_item'
    AND order_meta.meta_key = '_product_id'
    AND order_meta.meta_value = %d
    AND order_items.order_id IN (
        SELECT posts.ID AS post_id
        FROM {$wpdb->posts} AS posts
        WHERE posts.post_type = 'shop_order'
            AND posts.post_status IN ('wc-completed','wc-processing')
            AND DATE(posts.post_date) BETWEEN %s AND %s
    )
    GROUP BY order_meta.meta_value";

    return $wpdb->get_var($wpdb->prepare($sql, $product_id, $date_from, $date_to));
}

字符串

• 代码放在你的活动子主题（或主题）的functions.php文件中。或者也可以放在任何插件php文件中。*
  用途

//$count = wh_get_total_sold_by_product_id($my_custom_date, $product_id);
$count = wh_get_total_sold_by_product_id('2016-05-26', 56);

型
请注意：* 所有日期均为Y-m-d。*

代码经过测试，可以正常工作。

希望这有帮助！