protected void Page_Load(object sender, EventArgs e){ DateTime start = Convert.ToDateTime("2012-12-10"); DateTime end= Convert.ToDateTime("2012-12-18"); TimeSpan span = end - start; //int totleDay=span.Days; //DateTime spanNu = DateTime.Now.Subtract(span); int AllDays=Convert.ToInt32(span.TotalDays)+1;//差距的所有天數 int totleWeek = AllDays / 7;//差別多少周 int yuDay = AllDays % 7; //除了整個星期的天數 int lastDay = 0; if (yuDay == 0) //正好整個周 {  lastDay = AllDays - (totleWeek * 2); } else {  int weekDay = 0;  int endWeekDay = 0; //多余的天數有幾天是周六或者周日  switch (start.DayOfWeek)  {  case DayOfWeek.Monday:   weekDay = 1;   break;  case DayOfWeek.Tuesday:   weekDay = 2;   break;  case DayOfWeek.Wednesday:   weekDay = 3;   break;  case DayOfWeek.Thursday:   weekDay = 4;   break;  case DayOfWeek.Friday:   weekDay = 5;   break;  case DayOfWeek.Saturday:   weekDay = 6;   break;  case DayOfWeek.Sunday:   weekDay = 7;   break;  }  if ((weekDay == 6 && yuDay >= 2) || (weekDay == 7 && yuDay >= 1) || (weekDay == 5 && yuDay >= 3) || (weekDay == 4 && yuDay >= 4) || (weekDay == 3 && yuDay >= 5) || (weekDay == 2 && yuDay >= 6) || (weekDay == 1 && yuDay >=7))  {  endWeekDay =2;  }  if ((weekDay == 6 && yuDay < 1) || (weekDay == 7 && yuDay <5) || (weekDay == 5 && yuDay < 2) || (weekDay == 4 && yuDay < 3) || (weekDay == 3 && yuDay < 4) || (weekDay == 2 && yuDay < 5) || (weekDay == 1 && yuDay < 6))  {  endWeekDay = 1;  }  lastDay = AllDays - (totleWeek * 2) - endWeekDay; } lblTime.Text = lastDay.ToString();}