A general framework and reasoning models for time granularity

This paper presents a general framework to define time granularity systems. We identify the main choices differentiating the systems and investigate the formal relationships among granularities in these systems. The paper also introduces the notion of a network of temporal constraints with granularities emphasizing the semantical and computational differences from constraint networks with a single granularity. Consistency is shown to be NP-hard and an approximate algorithm proposed.