The basic syntax for the NETWORKDAYS function is: =NETWORKDAYS(Start Date,End Date,Holidays). With that in mind, let’s imagine that you want to find how many business days there are in January. First, enter the dates for January holidays as a list in A2:A3. Next, enter the start (1/1/2006) and ending (1/31/2006) dates in cells A9 and B9. Finally, click in the cell where you want to place the function (C9) and then type the function =NETWORKDAYS(A9,B9,A2:A3). If you set up the worksheet correctly, Excel should calculate 21 working days in January 2006.