variances of work center group of a machine group in AX 4.0.

Dear All,
I find difficult to understand variances of work center group of a machine group in AX 4.0.
The problem is that in the capacity tab of variance window (basic → work center groups
→ variance button → capacity tab. The days table consists of
work hour of the work center group from monday to friday based on calendar setup to it.
However when I click “>” button above to look for capacity from date to date,
the saturday and sunday filled in by the system, it should be empty because it’s closed
in the calendar. I have composed working times more than once with difference recurrence
but it still happened, I also copied what I set in AX 3.0 but still different with AX 3.0.
How to create capacity of work center group variances stable at saturday and sunday (the
closed day is not moving, but keep on existing saturday and sunday) ?
I appreciate your answer so much. tks in advance.

Rgds,