Preventive schedule plan date problem

Hi experts,

I prepared preventive plan for 1 yr with time base in scheduling parameter. But now problem is come for weekly off day ,all weekly off days plan shifted to next day.

How can I get the preventive plan for weekly off day ,say Sunday . All preventive come for 6 days in week ,so can get it for 7 days in week.

or How can I prepare Factory calender for 7 days working.

With Best Regards.

Avi DDS