Option Explicit
Private mblnTargetIsEmpty As Boolean
Private Sub Worksheet_Change(ByVal Target As Range)
With Target
If .Count = 1 Then _
If Not mblnTargetIsEmpty Then _
If .Address = Cells(Cells(Rows.Count, 6).End(xlUp).Row + IIf(.Value = vbNullString, 1, 0), 6).Address Then _
Cells(Cells(Rows.Count, 1).End(xlUp).Row + 1, 1).Value = Date
End With
End Sub
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
With Target
If .Count = 1 Then mblnTargetIsEmpty = IsEmpty(.Value)
End With
End Sub