public bool IsHoliday(DateTime date)
        {
            //土日・祝日ならばfalse
            //WEEKDAY = 月~日 != 平日
            var dayInfo = HolidayChecker.Holiday(date);

            if (dayInfo.holiday != HolidayChecker.HolidayInfo.HOLIDAY.WEEKDAY ||
                (dayInfo.week == DayOfWeek.Saturday || dayInfo.week == DayOfWeek.Sunday) ||
                (dayInfo.name == "12月31日" || dayInfo.name == "1月2日" || dayInfo.name == "1月3日"))
            {
                return(true);
            }
            return(false);
        }