This thesis describes "Hermes", a MOD developed as an extension of Post- greSQL. Hermes architecture is presented to show its general context of use through an SQL interface. The data types that comprise the data model are presented in three categories spatio-temporal, temporal, and spatial. A spatio- temporal 3D-Rtree index structure is proposed along with a collection of oper- ators that get support from it. Also, a showcase on an AIS dataset is presented to indicate some of the querying capabilities of Hermes. There are two cluster- ing algorithms implemented on Hermes that provide advanced functionality to the framework. Finally, the maturity of Hermes is shown by the fact that it is used in a real-world web application that o ers spatio-temporal querying functionality to its users.