Geographic Temporal Schema (GTS) extensible markup language is a component of the XML Schema Implementation of Geographic Information Metadata documented in ISO/TS 19139:2007. GTS includes all the definitions of http://www.isotc211.org/2005/gts namespace. The root document of this namespace is the file gts.xsd. The temporalObjects.xsd schema contains the XML implementation of TM_Object, TM_Primitive and TM_PeriodDuration from ISO 19108. The encoding of these classes is mapped to ISO 19136 temporal types and W3C built-in types.