A/R, G/L and A/P modules all have settings for the periods which are open. Open periods can be modified in each respective module, or it can be set in the G/L Module for all.
The G/L Module has a Starting and Ending Open Period, as does the A/R Module.
The A/P Module can have the Open Periods be set by system Company.
Make modifications to the opened and closed periods as needed and click save at the bottom of the screen.