Hello, i have this doubt...

i have two tables, the table "A" named Calls that contains 4 fields ( let's deal with tow of them, field 1: callopen(date when you open a call) and field 2: callclose(date when you close a phone call) ) type datetime and another one table "B" named hollidays with one datetime field.

Here's what i need to do:
- first i need to know how many total days are between the date when you open a call (callopen) and when you closed (callclose) but considering the hollidays ( allocated in the table hollidays ).

-After this and considering the previous requirement i need to consider the work time(this is between 8:00 am and 5:00 pm) of the result.

How i do this in a query? Thanks for the help