我需要以下列方式在时间 Span （fromDate，toDate）中找到 a) the number of total weeks 以及每周 b) the starting/ending dates (Monday, Sunday) ：

fromDate: Thursday, 9/1/2016
toDate: Friday, 10/14/2016
----------------------------------------------------
Week1: Thursday, 9/1/2016 - Sunday, 9/4/2016
Week2: Monday, 9/5/2016 - Sunday, 9/11/2016
Week3: Monday, 9/12/2016 - Sunday, 9/18/2016
Week4: Monday, 9/19/2016 - Sunday, 9/25/2016
Week5: Monday, 9/26/2016 - Sunday, 10/2/2016
Week6: Monday, 10/3/2016 - Sunday, 10/9/2016
Week7: Monday, 10/10/2016 - Friday, 10/14/2016

所以我还需要以正式的日历形式填充 incomplete weeks at the begging and at the end of the timespan （fromDate，toDate）

我已经在VB中实现了一个逻辑但是我错过了最后一周，在某些情况下，toDate日是：周一和周二 . 因此，某些参数或确切逻辑不是100％正确的 . 代码如下：

Public Shared Function GetWeeksFromTimespan(ByVal fromDate As Date, ByVal toDate As Date) As List(Of WeeksFromTimespan)

    Dim ListOfWeekTimespans As List(Of WeeksFromTimespan) = New List(Of WeeksFromTimespan)
    ' WeeksFromTimespan structure: WeekNumber As String, WeekNumber As Integer, fromDateWeek As Date, toDateWeek As Date
    ' fromDateWeek: week start date
    ' toDateWeek: week end date

    Dim Span As TimeSpan = toDate.Subtract(fromDate)

    Dim WeekCount As Integer = 0
    Dim Days As Integer = 0
    Dim DayCount As Integer = 0

    If Span.Days <= 7 Then

        If fromDate.DayOfWeek > toDate.DayOfWeek Then

            WeekCount = 2

            Dim DaysUntilEndOfFWeek As Integer = 0
            DaysUntilEndOfFWeek = 7 - fromDate.DayOfWeek

            Dim firstWeekEndDate As Date = fromDate.AddDays(DaysUntilEndOfFWeek)
            ListOfWeekTimespans.Add(New WeeksFromTimespan("Week1",1,fromDate,firstWeekEndDate))

            Dim secondWeekStartDate As Date = firstWeekEndDate.AddDays(1)
            ListOfWeekTimespans.Add(New WeeksFromTimespan("Week2",2,secondWeekStartDate,toDate))

        Else

            WeekCount = 1
            ListOfWeekTimespans.Add(New WeeksFromTimespan("Week1",1,fromDate,toDate))

        End If

    Else

        Days = Span.Days - 7 + CInt(fromDate.DayOfWeek)
        WeekCount = 1
        DayCount = 0

        Dim DaysUntilEndOfFWeek As Integer = 0
        DaysUntilEndOfFWeek = 7 - fromDate.DayOfWeek

        While DayCount <= Days

            If(DaysUntilEndOfFWeek>0) Then

                ListOfWeekTimespans.Add(New WeeksFromTimespan("Week" + WeekCount.ToString,WeekCount,fromDate.AddDays(DayCount),fromDate.AddDays(DaysUntilEndOfFWeek)))
                DayCount += DaysUntilEndOfFWeek+1
                WeekCount += 1
                DaysUntilEndOfFWeek = 0

            Else

                If(fromDate.AddDays(DayCount+6)<=toDate) Then
                    ListOfWeekTimespans.Add(New WeeksFromTimespan("Week" + WeekCount.ToString,WeekCount,fromDate.AddDays(DayCount),fromDate.AddDays(DayCount+6)))
                Else
                    ListOfWeekTimespans.Add(New WeeksFromTimespan("Week" + WeekCount.ToString,WeekCount,fromDate.AddDays(DayCount),toDate))
                End If

                DayCount += 7
                WeekCount += 1

            End If

        End While

    End If

    return ListOfWeekTimespans

End Function

但是，当上一个日期（toDate）在星期一，星期二时，上面的代码不会填充最后一个INCOMPLETE WEEK . 例如：

fromDate: 1/9/2016 (Thursday)
toDate: 11/10/2015 (Tuesday)
-----------------------------------------------
Week1: Thursday, 9/1/2016 - Sunday, 9/4/2016
Week2: Monday, 9/5/2016 - Sunday, 9/11/2016
Week3: Monday, 9/12/2016 - Sunday, 9/18/2016
Week4: Monday, 9/19/2016 - Sunday, 9/25/2016
Week5: Monday, 9/26/2016 - Sunday, 10/2/2016
Week6: Monday, 10/3/2016 - Sunday, 10/9/2016

所以使用上面的代码，我错过了最后一个不完整的一周：

Week7: Monday, 10/10/2016 - Tuesday, 11/10/2015.

需要优化此实施，以便能够准确计算两个日期之间“清晰”周的考试编号和日期 .

vb.net date logic