Hi "SKI_ .......,
To try to run something continuously or even just every second,
my not appear to have much of an effect if you have only one
workbook open, with only one sheet, but much beyond that you
are going to see an impact. Of course you could buy another
computer for $600 install $800 worth of software to simulate
a $6 clock not everyone has the extra space for that though.
Concerning clocks:
If you it is a clock that you want, and the reason is to see seconds,
you can get clocks to run in your task bar or that run in your browser
that will not impact your system as a clock within Excel would.
Within Excel that clock is interfering, even if that sheet is not visible.
TClockEx, Taskbar Clock Enhancer v1.4.2 «, Dale Nurden.
http://www.rcis.co.za/dale/tclockex/index.htm, to see seconds, date and
more in tray clock, CPU% not displaying on Win2000. Mouse over shows
your customized mini summary, mouse-click a calendar, right-click more options.
If you want to keep your clock at the right time
Time, Set Your Computer Clock Via the Internet,
NIST Network Time Service (NTS) -- nistime-32bit.exe.lnk,
http://www.boulder.nist.gov/timefreq/service/its.htm
More information on Date and Time in
http://www.mvps.org/dmcritchie/excel/datetime.htm
More information on ONTIME to run a macro at a scheduled
time or for an interval by reinvoking each time your macro runs. see
Chip Pearson's
http://www.cpearson.com/excel/ontime.htm
The clocks that you see that run in Excel use ONTIME.
You can have Excel enter the time as a constant with
Ctrl+Shift+: (colon) or you can use an Event macro to have
Excel enter the time in Column B when you place data or
update something in Column A (or other columns)
http://www.mvps.org/dmcritchie/excel/event.htm#addtime