Multi-Calendar Appointment Scheduling: Calendar Modeling and Constraint Reasoning

This article proposes a framework to model and reason on what we call multi-calendar appointment scheduling problems. Multicalendar appointment scheduling problems such as planning a phone conference of three persons in France, Tunisia, and Japan refer to various temporal conditions, involving arbitrary calendric types such as months (Islamic months are defined differently from Gregorian months) possibly belonging to different calendars (e.g. the Gregorian calendar and the Islamic calendar). To solve such problems, we suggest a new class of Constraint Satisfaction Problems (CSPs); we call them Multi-Calendar CSPs. In this framework, the constraint variables are identified with finite, convex intervals in some calendric type and time constraints on such variables are expressed in terms of typed finite domain constraints. To solve time constraints which are defined on variables of different calendric types, a novel constraint, called calendar conversion constraint is proposed.