Amount of "business hours" between two dates

Hi guys, I'm not familiar with advanced functions much and unfortunately haven't found hint in older threads. What I want to do is to get amount of "business hours" between two dates.

Example: Business week is Mon-Fri, 8AM - 4PM. Starting date (e-mail received) is "2/13/2016 12:45:00 PM" and end date (response sent) is "2/16/2016 4:06 PM". It's 75.3h in total but it's "just" 16 business hours.


Any help would be really appreciated!

Thanks in advance.

You do not have the answer.
Probably because you're unclear.
I'm not so friendly with working hours, especially because of the differences US and EU
Try to see this example, you put an additional question that may help others to help you solve the problem.

BTW: How can it be 16 "business hours"?