Periods
Periods are used to add time-related information to events.
For example, a free loan may be offered to subscribers on each anniversary. This annual loan is valid for a period of two weeks.
A Period type is connected to an Event concept.
An event concept represents an event occurring during concept life, for example a change of season. An event concept marks the impact on a concept of a phenomenon internal or external to the concept. Concept events can be distinguished as concept start events, end events and intermediate events.
The Period is connected to an Individual event.
An individual event represents an event occurring during during the life of the individual. It is an instance of an event concept of the concept to which the individual is connected.
For more details, see "Using periods".