Caution
Definition of a Factory Calendar

The preceding figure shows the details of a factory calendar.
Definition of Special Rules

If you set up end-of-period volume rebate arrangements with your suppliers, for example, you will conduct interim or final settlement accounting on certain dates. You must specify these dates in the form of special rules. Quarterly settlement of volume rebate arrangements requires the special rules, as shown in this figure.
Hint
As well as the factory calendar, you can also use plant-specific planning calendars.
Planning calendars are located on the SAP Easy Access screen under Logistics → Materials Management → Material Requirements Planning (MRP) → MRP → Master Data → Planning Calendar → Create Periods (MD25). You can maintain planning calendars for material requirements planning and to define a planning cycle or for scheduling. You can also use planning calendars during the scheduling agreements process in Materials Management (MM). During the scheduling agreements process, planning calendars can be a part of a release creation profile.
The maintenance of planning calendars is independent from factory calendars. That means that changes to the factory calendar don’t update planning calendars.