Recently GRASS GIS has been extended to provide spatio-temporal modeling, processing, analysis and visualization capabilities based on the field based view of geographic data. Space time datasets were introduced to represent collections of time stamped raster, 3D raster and vector maps. A comprehensive set of new spatio-temporal modules were introduced that make the management, processing and visualization of massive time series data as easy as possible. The integrated temporal topology approach allows the investigation of temporal and spatial relationships between different space time datasets. New interfaces to spatio-temporal analysis and processing software as R, ParaView and CDO were implemented for seamless data exchange. These new capabilities transform GRASS into a comprehensive temporal GIS.