That sounds like an issue when the calendar doesn't reach far enough, per the product guide for Clarity Solution Pack:
"The time periods that display in the report and all of the amounts being converted to FTE depend on the report calendar table. This table is populated by running the Update Business Objects Report Tables job with the update reporting calendar option checked. This job populates calendar periods and calculates FTE amounts based on the availability of the resource with Resource ID of 'admin' and the time slice with the name MONTHLYRESOURCEAVAILCURVE (Administration/Data Administration-Time Slices). This time slice must be configured to cover the periods displayed in this report or the report will not calculate FTE data for those periods. "
and obviously time slicing job should be run as well