Only way would be to run a macro continuously (or periodically) and either
update the cell or cause a calculate. In either case, you will find Excel's
responsiveness will be adversely affected. Obviously running periodically
will be less intrusive

http://www.cpearson.com/excel/ontime.htm
Chip Pearson's page on the use of Ontime

--
Regards,
Tom Ogilvy

"Khalid Ismail" <Khalid wrote in message
...
The NOW function changes only when the worksheet is calculated or when a
macro that contains the function is run. It is not updated continuously.
So, please How i can countinuously update time?