.NET Framework

So the user can select 2 different dates, a start date and an end date from 2 calendars, when they click 'add' the dates between&including the dates selected will be added to the DB, each date as a separate record.
 
This works fine however I dont want weekends to be added to the DB.
 
Iv updated the UI of datepicker http://www.kelvinluck.com/assets/jquery/datePicker/v2/demo/datePickerCustomCellRender.html but if a user selects fri-mon for example fri,sat,sun and mon will be added to the db Iv tried to only run the code if datyofweek is not saturday or sunday

 public ActionResult listHolidays(Holiday holiday, int? PersonId, string HolidayDate, string endDate)
        {
            DateTime startDates = Convert.ToDateTime(HolidayDate),
                     endDates = Convert.ToDateTime(endDate);
 
            while (startDates <= endDates)
            {
                if (startDates.DayOfWeek != DayOfWeek.Saturday || startDates.DayOfWeek != DayOfWeek.Sunday)
                {
                    Holiday holiday1 = new Holiday();
                    holiday1.PersonId = PersonId.Value;
                    holiday1.HolidayDate = startDates;
              
                    db.Holidays.AddObject(holiday1);
                    db.SaveChanges();
 
                    //say start date is 10. AddDays(1) will make it 11 then return it to startDates in 'startDates' = startdates,
                    //but doesnt chage the value of startdates = 'startdates'
                   // startDates = startDates.AddDays(1);

                     startDates = startDates.AddDays(1);
                }
            }
 
            return RedirectToAction("Index");
        }