Here's one way to put a timer in a cell.
There are plenty of other ways, but this
will get you looking along these lines.
Post back if unsure;
<PRE><FONT color=#008000>'// Place this code in the Thisworkbook object module
</FONT>
Private Sub<FONT color=blue> Workbook</FONT>_Open()
<FONT color=#008000>'// Format the cell as required
</FONT>
<FONT color=blue>Range</FONT>("A1").NumberFormat = "mm/dd/yy hh:mm:ss"
StartTimer
<FONT color=blue>End Sub</FONT>
Private Sub<FONT color=blue> Workbook</FONT>_BeforeClose(Cancel <FONT color=blue>As</FONT> <FONT color=blue>Boolean</FONT>)
StopTimer
<FONT color=blue>End Sub</FONT>
<FONT color=#008000>'// Place this code in a STD Module
</FONT>
<FONT color=blue>Option Explicit</FONT>
<FONT color=blue>Dim </FONT>T
<FONT color=blue>Sub </FONT>StartTimer()
T = Now + TimeValue("00:00:01")
Application.OnTime T, "Update"
<FONT color=blue>End Sub</FONT>
<FONT color=blue>Sub </FONT>Update()
<FONT color=blue>Range</FONT>("A1").Value = Now
<FONT color=blue>Call</FONT> StartTimer
<FONT color=blue>End Sub</FONT>
<FONT color=blue>Sub </FONT>StopTimer()
<FONT color=blue>On Error</FONT> <FONT color=blue>Resume </FONT><FONT color=blue>Next</FONT>
Application.OnTime T, Procedure:="Update", Schedule:=False
<FONT color=blue>End Sub</FONT>
</PRE>