Calculate hours difference between 2 dates excluding weekends holidays and non working time

Hi,

I need the hours difference between two dates in two different tables, exluding weekends, holidays and non working time which is from 11PM till 6AM. For instance first date is friday 9PM and second date is tuesday 7AM. Monday is a holiday. Hours difference is then 3, which is 2 hours on Friday (from 9 till 11PM) and 1 hour on Tuesday (from 6 till 7AM).

Question is how to calculate this and how to create a table with weekends and holidays of our company, or is there another method to define this?