SchoolLeader accounting uses both the current accounting period and the next accounting period to reconcile transactions. If you are within one period of the last period in your fiscal calendar, SchoolLeader will give you a warning that it is time to extend your fiscal calendar. This applies to all 3 fiscal calendars; A/R, A/P and G/L.
To extend your fiscal calendar, refer to chapter 3.4 Defining Your Fiscal Calendar.