Not only Sat. and Sun don't work. For example.
2016-06-09 is the Dragon Boat Festival of China.
That mean's Chinese don't work from 2016-06-09 to 2016-06-11,
but they have to work at 2016-06-12 (Sunday).
So, I hope admin can set which non-workday need to convert workday ,
and which workday don't need work.
And make it effective In gantt view, or calculate workdays.