Your statement is not precise. Excel clearly does use full double precision
for time/date values, as the original post illustrates. It is true that only
5 decimal places are needed to resolve seconds (1/24/60/60 =
0.0000115740740740741 ~ 1E-5) or 6 decimal places to resolve tenths of a
second (the highest resolution in a time format). However, you can get
higher resolution time values for timing code
http://support.microsoft.com/?kbid=172338

Jerry

"Sasa Stankovic" wrote:

as I said - excel uses 10 decimal places for time/date not 15! for regular
numbers he uses 15 but with date/time only 10 -- 5 is good for calculation
or comparison (unless you're quantum physics...)