This function will calculate the number of working days between two dates.
It will exclude weekends and any holidays.
Holidays : This is a list of dates which will be excluded from the calculation, such as Xmas
and Bank holidays.
The result will be shown as a number.
The calculation does not include the last day. The result of using 1-Jan-98 and 5-Jan-98 will
give a result of 4. To correct this add 1 to the result. =NETWORKDAYS(Start,End,Holidays)+1
The following example shows how a list of Holidays can be created.