MySQL. How to get the difference between two dates excluding weekends?

Question

MySQL

Hello.
Have date#1 = 2017-01-26 10:59:17
Have date#2 = 2017-01-27 11:34:55
How to get the difference between them while excluding holidays?
In this example, 28.29 is the weekend. Accordingly, somehow these 48 hours must be excluded from the difference ..
Thank you in advance!
PS
So far I'm counting the difference like this:
TIMESTAMPDIFF(SECOND, date1, date2)

Answer 1

1. Weekends are not just weekends.
2. Saturday and Sunday are not necessarily days off.
3. There are not necessarily 24 hours in a day.
pp. 1 and 2 are regulated by law, 3 robots can count themselves for the current time zone.

Answer 2

Create and use the "Calendar" table, where weekends and holidays are indicated, if necessary, working hours. Data can be taken, for example, a production calendar .