ABSTRACT
The great majority of GIS developments have dealt with reality and related problems utilising multiple static databases. Time has only been used as an attribute to index specific facts. Imprecise, nevertheless very useful and frequently used knowledge of time (including order and intervals) has not been possible yet. Furthermore, formalisation of change between two different states (facts or situations) in time has not been developed. There still seem to be major conceptual problems in dealing with spatial change in GIS. Spatial change is intrinsically associated with time.
