networkdays function

[NYTOG]

I am using networkdays function, however, it seems to me the no of working
days returned is not consistant.

e.g.
cell A1 is 1/5/2010
cell A2 is 1/8/2010
cell A3 is 1/9/2010

in cell A4, type =networkdays(A1, A2)=4
in cell A5, type =networkdays(A1,A3) =4

by counting physically from the calendar, from 1/5/2010 to 1/8/2010 is 4
working days and from 1/5/2010 to 1/9/2010 should be 5 working days, why the
formula return 4?

I actually tested couple of other days as well, whenever the end day is
friday, this problem show up.

Any idea?

 

[PJ]

Hi NYTOG

According to my calendar January 9 2010 is a Saturday, so Excel is correct
in not counting it as a workday.