Abstract: Temporal modeling and calculus arc the fundamental logic problems in temporal information system. From the view of granularities, the semantics and properties of temporal granularities were discussed according to the partilion. The temporal primitives were characterized based on temporal granularities. Furthermore, conversion operators and their relationship were analyzed with different granularities; the calculus system of their relationship was constructed from the point view of algebraic system.

Key words: Temporal,Granularity,Temporal calculus