Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("A1:A65536")) Is Nothing Then
Target.Offset(0, 1).Value = CDate(Format(Now(), "hh:mm:ss DD.MM.YY"))
End If
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("A1:A65536")) Is Nothing Then
    If Target.Offset(0, 1) = "" Then
    Target.Offset(0, 1).Value = CDate(Format(Now(), "hh:mm:ss DD.MM.YY"))
    End If
End If
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim d0_ As Range, d_ As Range
    Set d0_ = Intersect(Target, Columns(1))
    If Not d0_ Is Nothing Then
        Application.ScreenUpdating = 0
        cal_ = Application.Calculation
        Application.Calculation = xlCalculationManual
        Application.EnableEvents = 0
        For Each d_ In d0_
            With d_
                If .Value = "" Then
                    .Offset(, 1).ClearContents
                    d_.Resize(, 2).Borders.LineStyle = xlNone
                Else
                    .Offset(, 1) = CDate(Format(Now(), "hh:mm DD.MM.YY"))
                    d_.Resize(, 2).Borders.Weight = xlThin
                End If
            End With
        Next d_
        Application.EnableEvents = 1
        Application.Calculation = cal_
        Application.ScreenUpdating = 1
    End If
End Sub

                Else
                    .Offset(, 1) = Now
                    .Offset(, 1).NumberFormat = "yyyy/mm/dd h:mm"
                    d_.Resize(, 2).Borders.Weight = xlThin
                End If

.Offset(, 1) = CDate(Format(Now(), "hh:mm DD.MM.YY"))