Public stopMe As Boolean 
Public resetMe As Boolean 
Public myVal As Variant 
Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean) 
    If Target.Column = 1 Then 
        If Target.Value = myVal And Target.Value <> "" Then 
             'Changed
            Dim startTime, finishTime, totalTime, timeRow 
            startTime = Timer 
            stopMe = False 
            resetMe = False 
            myTime = Target.Offset(, 2).Value 
            Target.Offset(, 1).Select 
startMe: 
            DoEvents 
            timeRow = Target.Row 
            finishTime = Timer 
            totalTime = finishTime - startTime 
            Target.Offset(, 1).Value = Format(myTime + totalTime, "0.0000") & " Seconds" 
            If resetMe = True Then 
                Target.Offset(, 1).Value = 0 
                Target.Offset(, 2).Value = 0 
                stopMe = True 
            End If 
            If Not stopMe = True Then 
                Target.Offset(, 2).Value = totalTime 
                GoTo startMe 
            End If 
            Cancel = True 
            End 
        Else 
             'Not Changed
            stopMe = True 
            Cancel = True 
        End If 
    End If 
End Sub 
Private Sub Worksheet_SelectionChange(ByVal Target As Range) 
    myVal = Target.Value 
End Sub