Excel DateDif() or =NETWORKDAYS()

Question

I tried the functions listed in the subject, DateDif() and =NETWORKDAYs() with these parameters, =NETWORKDAYS(Today(), 5/31/2015). Now I keep getting an unusually large number for the context on my spreadsheet. I am not sure why. Any ideas?

=DateDif(5/31/2015,Today(), "D")

I get:

42237.0

This obviously is not true. Since in the last few months there have not been nearly that many days.

Answer 1

The slashes are interpreted as division signs so 5 ÷ 31 ÷ 2015 is almost 0, which means Jan 00, 1900. (I kid you not, there is such a date in Excel).

Use this:

=DateDif(DATE(2015,5,31),Today(), "D")

Which gives 82 days.