単純注文番号の考え方(時間＋タイムスタンプ)

		   //               YYYYMMDD(   ) +         
            let currDate = new Date();
            let year = currDate.getFullYear();
            let month = currDate.getMonth() + 1 < 10 ? "0" + (currDate.getMonth() + 1): currDate.getMonth() + 1;
            let day = currDate.getDate()<10 ? "0"+currDate.getDate() : currDate.getDate();
            
            //     
            let date = year + month + day; //20190524
            
            //       
            let timestamp = Date.parse(currDate); //155866554500
            
            //    
            let orderId = date + timestamp; //20190524155866554500