如何获得给定的日期避开假期14天前(How to get 14 days prior to the

在我的系统，该法案的到期日必须在发出日期后14天内。
我有到期日和我想知道发行日期。
我要计算：

issued date = 14 days prior to the due date

但有14天必须是工作日，节假日不。
假期存储在像这样的表“tblHolidayMaster”，

日期说明
2012/05/13母亲节
2012/06/02 Saturnday
2012年12月25日圣诞节

我如何计算的发行日期间避免假期？
感谢您对所有您的利益和回复。

Answer 1:

我会使用类似下面的函数（我使用）计算日期

public static DateTime AddBusinessDays(DateTime date, int days)
 {
    if (days == 0) return date;

   if (date.DayOfWeek == DayOfWeek.Saturday)
   {
    date = date.AddDays(2);
    days -= 1;
  }
  else if (date.DayOfWeek == DayOfWeek.Sunday)
  {
    date = date.AddDays(1);
    days -= 1;
  } 



 date = date.AddDays(days / 5 * 7);
 int extraDays = days % 5;

 if ((int)date.DayOfWeek + extraDays > 5)
 {
    extraDays += 2;
 }

int extraDaysForHolidays =-1;
//Load holidays from DB into list
List<DateTime> dates = GetHolidays();

while(extraDaysForHolidays !=0)
{

 var days =  dates.Where(x => x >= date  && x <= date.AddDays(extraDays)).Count;
 extraDaysForHolidays =days;
 extraDays+=days;  
}


return date.AddDays(extraDays);

}

没有测试的AST节不放假

Answer 2:

我去的直线前进循环的解决方案，所以这将是长的时间间隔慢。但对于短的间隔像14天，它应该是相当快的。

你需要在构造函数中的假期通过。实例BusinessDays是不可改变的，可重复使用。在实践中，你可能会使用一个IoC单或类似的结构得到它。

AddBusinessDays引发ArgumentException如果开始日期为非工作日，因为你没有指定如何处理这种情况。特别AddBusinessDays(0)在非工作日否则将有奇怪的特性。它会打破任何时间反演对称性，或返回一个非营业日。

public class BusinessDays
{
    private HashSet<DateTime> holidaySet;
    public ReadOnlyCollection<DayOfWeek> WeekendDays{get; private set;}

    public BusinessDays(IEnumerable<DateTime> holidays, IEnumerable<DayOfWeek> weekendDays)
    {
        WeekendDays = new ReadOnlyCollection<DayOfWeek>(weekendDays.Distinct().OrderBy(x=>x).ToArray());
        if(holidays.Any(d => d != d.Date))
            throw new ArgumentException("holidays", "A date must have time set to midnight");
        holidaySet = new HashSet<DateTime>(holidays);
    }

    public BusinessDays(IEnumerable<DateTime> holidays)
        :this(holidays, new[]{DayOfWeek.Saturday, DayOfWeek.Sunday})
    {
    }

    public bool IsWeekend(DayOfWeek dayOfWeek)
    {
        return WeekendDays.Contains(dayOfWeek);
    }

    public bool IsWeekend(DateTime date)
    {
        return IsWeekend(date.DayOfWeek);
    }

    public bool IsHoliday(DateTime date)
    {
        return holidaySet.Contains(date.Date);
    }

    public bool IsBusinessDay(DateTime date)
    {
        return !IsWeekend(date) && !IsHoliday(date);
    }

    public DateTime AddBusinessDays(DateTime date, int days)
    {
        if(!IsBusinessDay(date))
            throw new ArgumentException("date", "date bust be a business day");
        int sign = Math.Sign(days);
        while(days != 0)
        {
            do
            {
              date.AddDays(sign);
            } while(!IsBusinessDay(date));
            days -= sign;
        }
        return date;
    }
}

Answer 3:

我认为这是你需要什么。这很简单，我已经测试过它，这是工作......而且这还不是写在数据库中的函数或SP，而写在C＃中复杂的代码个不错的办法......（日期的变化列名作为你的D b。）

令其功能或SP，你想要什么。

注意：评论“星期六”和“星期日”的检查。如果在你的表reocrds已经添加。

declare @NextWorkingDate datetime
declare @CurrentDate datetime
set @CurrentDate = GETDATE()
set @NextWorkingDate = @CurrentDate 
declare @i int = 0
While(@i < 14)
Begin
    if(((select COUNT(*) from dbo.tblHolidayMaster where convert(varchar(10),[Date],101) like convert(varchar(10),@NextWorkingDate,101)) > 0) OR DATENAME(WEEKDAY,@NextWorkingDate) = 'Saturday' OR DATENAME(WEEKDAY,@NextWorkingDate) = 'Sunday')
    Begin
        print 'a '  
        print @NextWorkingDate
        set @NextWorkingDate = @NextWorkingDate + 1
        CONTINUE
    End
    else
    Begin
        print  'b ' 
        print @NextWorkingDate
        set @NextWorkingDate = @NextWorkingDate + 1
        set @i = @i + 1
        CONTINUE
    End
End
print @NextWorkingDate

Answer 4:

我计算发行日期间避免你的表“tblHolidayMaster”只有你的假期。

 int addDay = -14;
  DateTime dtInputDay = System.DateTime.Now;//Your input day
  DateTime dtResultDate = new DateTime();
  dtResultDate = dtInputDay.AddDays(addDay);
  bool result = false;
  string strExpression;
  DataView haveHoliday;
  while (!result) {
      strExpression = "Date >='" + Convert.ToDateTime(dtResultDate.ToString("yyyy/MM/dd")) + "' and Date <='" + Convert.ToDateTime(dtInputDay.ToString("yyyy/MM/dd")) + "'";
      haveHoliday = new DataView(tblHolidayMaster);
      haveHoliday.RowFilter = strExpression;
      if (haveHoliday.Count == 0) {          
        result = true;
      } else {
          addDay = -(haveHoliday.Count);
          dtInputDay = dtResultDate.AddDays(-1);
          dtResultDate = dtResultDate.AddDays(addDay);
      }
  }

您的发行日期是dtResultDate