A Framework for User Defined Periodic Calendars

Most contemporary calendaring and scheduling systems represent time using the Gregorian calendar. Systems that are more conscious of internationalization provide a choice of several predefined calendaring systems. We have observed that humans are constantly contriving new systems of time description that reflect specific domains of their activities, such as academic, agriculture, finance, sports calendars, and more. In this paper we investigate a model that offers the flexibility of adding an arbitrary time description system to an existing calendaring and scheduling application. Such a model allows organizations to define their own calendar and the periods of time that are significant to their activities, so that users within the organization can view, plan and reason about time in terms relevant to their domain.
Most of the formal symbolic definitions of calendars are logic oriented, and use constraints to represent valid dates, and to represent transformation rules between different calendars. This type of representation is not intuitive, and requires many hours of learning for a casual user to master. In this work we took an object oriented approach to representing calendars. The temporal concepts are represented by classes that are organized in hierarchies, and are related to each other via aggregation. A calendar definition is created by declaring instances of these classes, and the actual links between them.

By: Yael Shaham-Gafni, Daniel A. Ford

Published in: RJ10282 in 2003


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