Private Function GetTimeSpan
        (hour1 As Integer, minute1 As Integer, second1 As Integer,
         hour2 As Integer, minute2 As Integer, second2 As Integer) As TimeSpan
 
        Dim day1 As Integer = 1, day2 As Integer = 1
 
        If hour1 = 24 Then
            If (minute1 <> 0 Or second1 <> 0) Then
                Throw New ArgumentException("Unzulässige Zeitangabe")
            End If
            hour1 = 0 : day1 = 2 'Tageswechsel
        End If
 
        If hour2 = 24 Then
            If (minute2 <> 0 Or second2 <> 0) Then
                Throw New ArgumentException("Unzulässige Zeitangabe")
            End If
            hour2 = 0 : day2 = 2
        End If
 
        Dim dt1 As New Date(1, 1, day1, hour1, minute1, second1)
        Dim dt2 As New Date(1, 1, day2, hour2, minute2, second2)
 
        Return New TimeSpan(dt2.Ticks - dt1.Ticks)
 
End Function