VBA A simple second Timer

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
'For example: Start / Stop the timer every time the cell. 
'but may also be placed on a button or another ... 
   TimeOnOFF = Not TimeOnOFF
    If TimeOnOFF Then Timer
End Sub

Public TimeOnOFF As Boolean

Sub Timer()
Dim S As Integer
    While TimeOnOFF = True
        If Second(Now) > S Or Second(Now) = 0 Then
            '  Run code
            '....
            'for example
            Sheets("shee1").Range("A1").Value = Time
            
            S = Second(Now)
        End If
        DoEvents
    Wend
    
End Sub