Dim FirstDate As Date
        Dim IntervalType As String
        Dim Number As Integer
 
        '##########
        FirstDate = CDate(BuchungsdatumTextBox.Text).ToShortDateString
        Number = nud_Buchungswiederholung.Value        'Buchung monatlich 
        ' wiederholen
        IntervalType = "m"
        For i As Integer = 0 To Number
           Dim D As date FirstDate.Add(IntervalType, i, FirstDate)
 
           'und dann der Datatable hinzufügen
        Next

  Dim DateFrom As Date = New Date(2019, 1, 1)
        Dim DateTo As Date = New Date(2019, 12, 31)
        Dim n As Integer = CInt((DateTo.Date - DateFrom.Date).TotalDays)
 
        For i As Integer = 0 To n
 
            Dim D As Date = DateFrom.Date.AddDays(i)
 
            Dim DR As DataRow = mDT.NewRow
            'DR.Item(0) = Nothing
            DR.Item(1) = D.ToString("ddd")
            DR.Item(2) = D
 
            If D.DayOfWeek = DayOfWeek.Saturday Or D.DayOfWeek = _
              DayOfWeek.Sunday _
              Then
                DR.Item(3) = D
                DR.Item(4) = D
                DR.Item(5) = New TimeSpan(0, 0, 0).TotalMinutes
                DR.Item(6) = New TimeSpan(0, 0, 0).TotalMinutes
                DR.Item(7) = "WE"
            Else
                DR.Item(3) = D.Add(New TimeSpan(7, 30, 0))
                DR.Item(4) = D.Add(New TimeSpan(16, 0, 0))
                DR.Item(5) = New TimeSpan(0, 45, 0).TotalMinutes
                DR.Item(6) = New TimeSpan(6, 48, 0).TotalMinutes
                DR.Item(7) = "Anwesend "
            End If
 
            mDT.Rows.Add(DR)
        Next