86,400 - it's not a good idea, it's just the law.

["Keith F. Lynch" <cbmvax!uunet!LARCH.LCS.MIT.EDU!kfl>]

>> Now if you want to redefine all our clocks to fill a day with
>> 100,000 units approximately equal to 0.864 seconds ...

> In the late 50's, Donald Knuth (yes, THE Donald Knuth) published a
> piece entitled "The Potrzebie System of Units" in Mad Magazine, in
> which he did just that.

He doesn't have priority.  Shortly after their 1789 revolution, the
French established a new clock, in which there were 10 hours in a day,
100 minutes in an hour, and 100 seconds in a minute, thus 100,000
seconds in a day.  (At the same time, they established a new calendar
with twelve 30 day months of four 10 day weeks plus 5 or 6 leap days
per year.  Both soon fell into disuse, and were officially abolished
by Napoleon.  The system of weights and measures they introduced at
the same time had better success, and is now used everywhere but
the US.)
								...Keith