向日期添加工作日

• 下载源代码 - 89.7 KB

引言

你是否曾经需要向日期添加天数，然后确保这些天数都是工作日？

我确实遇到过很多次这种情况，当一位初级开发人员问我如何处理时，我想与大家分享一下。这只适用于标准工作周。也就是说，周一到周五。周六和周日将被视为周末。代码很容易理解，如果需要，应该很容易修改以适应你自己的特定用途。

Using the Code

要简单地向起始日期添加 2 个工作周，你可以调用函数 CalculateTenBusinessDaysFromInputDate 并将 StartDate 传递给它。该函数将返回一个距离 StartDate 有 10 个工作日的日期。如果 Startdate 是 周六，我们只需向 StartDate 传递的值添加 16 天。如果 StartDate 是 周日，则向 StartDate 添加 15 天。对于一周的任何其他日期，我们只需向 StartDate 添加 14 天。

VB.NET

Public Function CalculateTenBusinessDaysFromInputDate(ByVal StartDate As Date) As Date
    'This simply adds at least 2 full weeks to the start date.

    Select Case StartDate.DayOfWeek

        Case DayOfWeek.Sunday
            'if the start date is not a sunday you need to add 
            '1 day to push it to a monday that is why the number is 15.
            Return StartDate.AddDays(15)
        Case DayOfWeek.Monday, DayOfWeek.Tuesday, _
		DayOfWeek.Wednesday, DayOfWeek.Thursday, DayOfWeek.Friday
            'if the start date is any other day then just add 14 days to the start date.
            Return StartDate.AddDays(14)
        Case DayOfWeek.Saturday
            'if the start date is on a Saturday you need to add 
            '2 days to push it to a monday that is why the number is 16.
            Return StartDate.AddDays(16)
        Case Else
            Return StartDate

    End Select

End Function

C#

public System.DateTime CalculateTenBusinessDaysFromInputDate(System.DateTime StartDate)
{
    //This simply adds at least 2 full weeks to the start date.

    switch (StartDate.DayOfWeek)
    {
        case DayOfWeek.Sunday:
            //if the start date is not a sunday you need to add 
            //1 day to push it to a monday that is why the number is 15.
            return StartDate.AddDays(15);
            break;
        case DayOfWeek.Monday:
        case DayOfWeek.Tuesday:
        case DayOfWeek.Wednesday:
        case DayOfWeek.Thursday:
        case DayOfWeek.Friday:
            //if the start date is any other day then just add 14 days to the start date.
            return StartDate.AddDays(14);
            break;
        case DayOfWeek.Saturday:
            //if the start date is on a Saturday you need to add 
            //2 days to push it to a monday that is why the number is 16.
            return StartDate.AddDays(16);
            break;
        default:
            return StartDate;
    }
}

这段代码更具现实意义。要使用 CalculateBusinessDaysFromInputDate 函数，你需要提供 StartDate 以及要添加到 StartDate 的工作日数量。在 CalculateBusinessDaysFromInputDate 中，我们首先检查 StartDate 是否为 周六 或 周日。如果是，则我将工作日数量减少 1。我这样做是因为我们不希望结果日期是 11 个工作日之后。注意：我没有在 CalculateTenBusinessDaysFromInputDate 中这样做。 例如，如果 StartDate 是 周一，并且我们向其添加 12 个工作日，那么结果应该在星期三。在返回结果日期之前，我们需要确保该日期不是周末。如果是，我会将日期移动到下一个 周一。你也可以通过简单地使用 .AddDays() Date 函数并传递一个负数来将日期移回之前的 周五。例如 .AddDays(-2)。

VB.NET

Public Function CalculateBusinessDaysFromInputDate_
	(ByVal StartDate As Date, ByVal NumberOfBusinessDays As Integer) As Date
    'Knock the start date down one day if it is on a weekend.
    If StartDate.DayOfWeek = DayOfWeek.Saturday Or StartDate.DayOfWeek = _
	DayOfWeek.Sunday Then
        NumberOfBusinessDays -= 1
    End If
    
    For index = 1 To NumberOfBusinessDays
        Select Case StartDate.DayOfWeek
            Case DayOfWeek.Sunday
                StartDate = StartDate.AddDays(2)
            Case DayOfWeek.Monday, DayOfWeek.Tuesday, DayOfWeek.Wednesday, _
				DayOfWeek.Thursday, DayOfWeek.Friday
                StartDate = StartDate.AddDays(1)
            Case DayOfWeek.Saturday
                StartDate = StartDate.AddDays(3)
                
        End Select
        
    Next
    
    'check to see if the end date is on a weekend.
    'If so move it ahead to Monday.
    'You could also bump it back to the Friday before if you desired to. 
    'Just change the code to -2 and -1.
    If StartDate.DayOfWeek = DayOfWeek.Saturday Then
        StartDate = StartDate.AddDays(2)
    ElseIf StartDate.DayOfWeek = DayOfWeek.Sunday Then
        StartDate = StartDate.AddDays(1)
    End If
    
    Return StartDate
    
End Function

C#

public System.DateTime CalculateBusinessDaysFromInputDate
	(System.DateTime StartDate, int NumberOfBusinessDays)
    {
        //Knock the start date down one day if it is on a weekend.
        if (StartDate.DayOfWeek == DayOfWeek.Saturday | 
			StartDate.DayOfWeek == DayOfWeek.Sunday)
        {
            NumberOfBusinessDays -= 1;
        }
        
        int index = 0;
        
        for (index = 1; index <= NumberOfBusinessDays; index++)
        {
            switch (StartDate.DayOfWeek)
            {
                case DayOfWeek.Sunday:
                    StartDate = StartDate.AddDays(2);
                    break;
                case DayOfWeek.Monday:
                case DayOfWeek.Tuesday:
                case DayOfWeek.Wednesday:
                case DayOfWeek.Thursday:
                case DayOfWeek.Friday:
                    StartDate = StartDate.AddDays(1);
                    break;
                case DayOfWeek.Saturday:
                    StartDate = StartDate.AddDays(3);
                    break;
            }
        }
        
        //check to see if the end date is on a weekend.
        //If so move it ahead to Monday.
        //You could also bump it back to the Friday before if you desired to. 
        //Just change the code to -2 and -1.
        if (StartDate.DayOfWeek == DayOfWeek.Saturday)
        {
            StartDate = StartDate.AddDays(2);
        }
        else if (StartDate.DayOfWeek == DayOfWeek.Sunday)
        {
            StartDate = StartDate.AddDays(1);
        }
        
        return StartDate;
    }

关注点

这是一种非常简单的计算工作日的方法。它没有复杂的算法。
如果你需要计算过去的天数，这也可以正常工作。希望这在某种程度上有所帮助。

历史

• 2009 年 10 月 28 日：初始版本