Private Sub Worksheet_Change(ByVal Target As Range)

   On Error GoTo ws_exit:
   Application.EnableEvents = False
   If Target.Address = "$C$59" Then
       With Target
           .Offset(0, 1).Value = Format(Now, "dd mmm yyyy hh:mm")
       End With
   End If

ws_exit:
   Application.EnableEvents = True
End Sub
'This is worksheet event code, which means that it needs to be
'placed in the appropriate worksheet code module, not a standard
'code module. To do this, right-click on the sheet tab, select
'the View Code option from the menu, and paste the code in.

crazy person.. use a database for this type of activity