>Thanks,
>
>can you provide me with some instructions as to how to go about this, please?
>
>>You can have either a calculated field in a table or perform calculations in a stored procedure. If you go the second route, then I suggest to have Calendar table in your database. Having this Calendar table (that will put IsHoliday or IsWeekend for Holidays and Weekends) will make the calculations of Working days trivial.
>>
About adding Calendar table?

If so, check
http://blogs.lessthandot.com/index.php/DataMgmt/DataDesign/passing-multiple-ranges-to-stored-proced

I gave the script there.

Once you added the table, see, if you will be able to calculate the number of days. If you still will have problems, post back DDL and insert statements, I'll try to come up with the full solution.