Calculate the number of workdays using Excel

This is a cool function, that I didn’t know about.  I basically wanted to find out the number of working days between two dates.  Found the NETWORKDAYS function! This is extracted from the Help file ;-)

Description
Returns the number of whole working days between start_date and end_date. Working days exclude weekends and any dates identified in holidays. Use NETWORKDAYS to calculate employee benefits that accrue based on the number of days worked during a specific term.
Tip: To calculate whole workdays between two dates by using parameters to indicate which and how many days are weekend days, use the NETWORKDAYS.INTL function.

Syntax
NETWORKDAYS(start_date, end_date, [holidays])

The NETWORKDAYS function syntax has the following arguments:
Start_date    Required. A date that represents the start date.
End_date    Required. A date that represents the end date.
Holidays    Optional. An optional range of one or more dates to exclude from the working calendar, such as state and federal holidays and floating holidays. The list can be either a range of cells that contains the dates or an array constant of the serial numbers that represent the dates.