Dim arr As Variant
Private Sub Workbook_Open()
Dim lastzei As Long
lastzei = Cells(Rows.Count, Range("AB14").Column).End(xlUp).Row
arr = Range("AB14:AB" & lastzei)
End Sub
Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
Dim lastzei As Long
lastzei = Cells(Rows.Count, Range("AB14").Column).End(xlUp).Row
With Range("AB14:AB" & lastzei)
For i = 1 To .Cells.Count
If i > UBound(arr) Then
.Cells(i).Offset(0, 4).Value = Date
ElseIf .Cells(i) <> arr(i, 1) Then
.Cells(i).Offset(0, 4).Value = Date
End If
Next i
End With
End Sub