Public Class frmWerktage
 
    'ab hier ins Formular kopieren
 
    'Erstellen und Einrichten der Controls
 
    'Labels
    Dim lblStart As New Label With _
        {.Parent = Me, .Width = 200, .Text = "Startdatum: "}
 
    Dim lblEnde As New Label With _
        {.Parent = Me, .Left = 250, .Width = 200, .Text = "Enddatum: "}
 
 
    'DateTimePicker
    Dim WithEvents dtpStart As New DateTimePicker With _
        {.Parent = Me, .Top = 40, _
        .Width = 200, .Value = CDate("1.1.2013")}
 
    Dim WithEvents dtpEnde As New DateTimePicker With _
        {.Parent = Me, .Top = 40, .Left = 250, _
        .Width = 200, .Value = CDate("1.1.2013")}
 
 
    'Berechnungsbutton
    Dim WithEvents btnCompute As New Button With _
        {.Parent = Me, .Top = 100, _
        .Width = 200, .Text = "Werktage berechnen"}
 
    'Anzeige des Ergebnisses
    Dim lblWerktage As New Label With _
        {.Parent = Me, .Top = 100, .Left = 250, _
        .Width = 200, .Text = "", .BackColor = Color.LightGray}
 
 
    Private Sub btnCompute_Click(sender As Object, _
            e As System.EventArgs) Handles btnCompute.Click
 
        'Berechnung der Differenz zwischen den Daten (Werktage)
 
        Dim dt As Date = DateValue(dtpStart.Value.ToString)
        Dim dtend As Date = DateValue(dtpEnde.Value.ToString).AddDays(1)
        Dim c As Integer = 0
 
        If New TimeSpan(dtend.Ticks - dt.Ticks).Ticks <= 0 Then
            lblWerktage.Text = "Unplausibles Zeitintervall" : Exit Sub
        End If
 
        Do
            Dim wochentag As Integer = Microsoft.VisualBasic.Weekday(dt)
            'Unter Annahme: 1 = Sonntag, 7 = Samstag
            If wochentag > 1 And wochentag < 7 Then
                c += 1
            End If
            dt = dt.AddDays(1)
        Loop While dt < dtend
 
        lblWerktage.Text = "Werktage: " & CStr(c)
    End Sub
 
    Private Sub dtp_ValueChanged(sender As Object, e As System.EventArgs) _
        Handles dtpStart.ValueChanged, dtpEnde.ValueChanged
        lblWerktage.Text = ""
    End Sub
 
    'bis hier ins Formular kopieren
 
End Class