Option Explicit
Dim bAbort As Boolean
 
Private Sub Button_Click()
  If Button.Caption <> "Stop" Then
    bAbort = False
    Button.Caption = "Stop"
  Else
    Button.Caption = "Weiter"
    bAbort = True
  End If
End Sub
 
Private Sub DeineSub()
  Do
    <font color=green>' hier kommt Deine Zeitberechnung rein</font>
 
    DoEvents
  Loop Until bAbort
End Sub