Private Sub Workbook_Open()
 
Dim zeile As Long
zeile = 2
Do
monat = Month(Cells(zeile, 1))
If monat = 1 Then
    Rows(zeile).Delete
    zeile = zeile - 1
End If
 
zeile = zeile + 1
Loop Until Cells(zeile, 1).Value = ""
 
End Sub