On Mar 16, 1:30*pm, Bill Sharpe wrote:
Chip Pearson has an explanation of how Excel stores
dates and times at
http://www.cpearson.com/excel/datetime.htm.
There are six digits set aside to store 24 hours of time.
Do the math and you'll see that you won't get any closer
accuracy than tenths of a second.

Exactly how did you "do the math"?

First, Chip's description of the internal format is over-simplified
and frankly incorrect to the degree that you interpreted it (literally
6 digits "set aside" for time).

Second, even if we assume there are 6 digits for time, I do not see
how to "do the math" to reach the conclusion that you did. (Hint:
Try entering =0.01/86400 and format it as Number. How many decimal
places do you need?)

Nonetheless, your conclusion is correct.