Find working days in a month

Syntax of Networkdays formula:

networkdays(from this date, to this date, [add this holidays as well])

Examples of Excel Networkdays formula:
networkdays("12/1/2008","12/31/2008") = 23

Examples That Use Cell References

A1: 12/24/92
A2: 12/25/92

Then, type the following formula in cell D1:

=NETWORKDAYS(DATEVALUE("1/1/92"),DATEVALUE("12/31/92"),A1:A2)

-or-

A1: 1/1/92
A2: 12/31/92
A3: 12/24/92
A4: 12/25/92

Then, type the following formula in cell D1:

=NETWORKDAYS(A1,A2,A3:A4)