Finding the number of workdays (Monday through Friday) between two dates can't be done by simply subtracting one date from another. It requires a prewritten formula called the NETWORKDAYS function, which calculates the net number of workdays between two dates.

It's still June 9, 2010, and your vacation still starts on August 21, 2010, but now you want to find how many workdays until vacation. You would type the formula:

**=NETWORKDAYS(A2,A3)**

There are 53 workdays until vacation. The values in cells A2 and A3 are the arguments, information that tells NETWORKDAYS what to calculate. Parentheses separate the function from the **arguments**. Within the parentheses, a comma separates the arguments from each other.

**Note** After you type an equal (=) sign and the beginning letters of a function name, Excel displays a list of functions. To let Excel enter the name for you, select NETWORKDAYS from the list. Formula AutoComplete then displays the function argument names. You can finish the formula by using Formula AutoComplete, or you can ignore it and continue typing on your own.