我使用下面的代码减去两个日期
Dim OpenDate, ClosedDate As DateTime
dim Result as String
OpenDate = Convert.ToDateTime(some string contain date and time)
ClosedDate = Convert.ToDateTime(some string contain date and time)
Result = ClosedDate.Subtract(OpenDate).ToString
它工作正常，格式正确（天.小时：分钟：秒）
我需要的是
如果关闭日期和打开日期之间的时间段包含星期五或星期六，则从结果中减去
例如。如果结果 9.03:02:10 包含 2 个星期六和星期五，则它必须是 6.03:02:10 等等
【问题讨论】：
一种幼稚但易读的方法：
Public Shared Function GetBusinessDays(startDay As DateTime, endDay As DateTime) As Integer
Dim today = Date.Today
Dim weekend = {DayOfWeek.Saturday, DayOfWeek.Sunday}
Dim businessDays =
From d In Enumerable.Range(0, (endDay.Date - startDay.Date).Days + 1)
Select day = today.AddDays(d)
Where Not weekend.Contains(day.DayOfWeek)
Return businessDays.Count()
End Function
测试：
Dim days As Int32 = GetBusinessDays(Date.Now, Date.Now.AddDays(9))
Console.Write(days) ' 7
LINQ 查询首先创建从 0 到天的整数范围（+1，因为包括最后一天）。然后它通过today.AddDays(days) 创建Date 对象。由于weekend 是DayOfWeek 的数组，您可以使用Enumerable.Contains 仅获取不是周末日期的日期。最后一步是使用Enumerable.Count 执行查询以获取工作日数。
您可以通过为银行假日提供ParamArray 来改进它：
Public Shared Function GetBusinessDays(startDay As DateTime, endDay As DateTime, ParamArray bankHoliday As Date()) As Integer
Dim today = Date.Today
Dim nonWorkingDays = New HashSet(Of Date)(bankHoliday)
Dim weekend = {DayOfWeek.Saturday, DayOfWeek.Sunday}
Dim businessDays =
From d In Enumerable.Range(0, (endDay - startDay).Days + 1)
Select day = today.AddDays(d)
Where Not weekend.Contains(day.DayOfWeek) AndAlso Not nonWorkingDays.Contains(day)
Return businessDays.Count()
End Function
即使您没有银行假日，它也可以正常工作。如果你有一个或多个，你可以传递一个真正的数组作为参数，也可以传递单个对象，比如圣诞节：
Dim christmas = New Date(2014, 12, 25)
Dim days As Int32 = GetBusinessDays(Date.Now, Date.Now.AddDays(9), christmas)
或几个单一的对象：
Dim christmasEve = New Date(2014, 12, 24)
Dim days As Int32 = GetBusinessDays(Date.Now, Date.Now.AddDays(9), christmasEve, christmas)
【讨论】：
确实应该是：
Select day = startDay.AddDays(d)
因为指定范围的开始日可能并不总是今天。
【讨论】：