Dim Stunde As Integer ' = txtStunde.text
    Dim Minute As Integer ' = txtMinute.text
    Dim Sekunde As Integer ' = txtSekunde.text
 
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Timer1.Tick
        Dim d As DateTime = DateTime.Now
        If d.Hour >= Stunde And d.Minute >= Minute And d.Second >= Sekunde Then
            ' runterfahren
        End If
    End Sub