Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
 
        ToolStripStatusLabel2.Text = TimeOfDay
 
        ' Laufzeit
        meinzähler += 1
        ToolStripStatusLabel4.Text = SecToTime(meinzähler)
 
    End Sub

Private Sub Datenabfrage_Tick(sender As Object, e As EventArgs) Handles _
  Datenabfrage.Tick
 
        Using wc As New Net.WebClient
            Try
                Dim abruf As String = wc.DownloadString(My.Settings.Kanal)
 
                Label1.Text = abruf
                Label1.Text = Replace(Label1.Text, ".", ",")
                If Label2.Text = "0" Then
                    Label2.Text = Label1.Text
                End If
 
 
                Dim differenz As Double = Label1.Text - Label2.Text
                Dim Platzhalter As String = "    "
                Label3.Text = Platzhalter & (String.Format("{0:n4}", _
                  differenz)) '& " kw/h"
                Label8.Text = Platzhalter & (String.Format("{0:n2}", differenz _
                * (My.Settings.Preis / 100))) & " €"
 
            Catch ex As Exception
                'Label1.Text = "offline"
            End Try
        End Using
 
 
    End Sub

Dim differenz As Double = Label1.Text - Label2.Text