: This paper brings together two research areas, i.e. “Data Warehouses” and “Temporal Databases”, involving representation of time. Looking at temporal aspects within a data warehouse, more similarities than differences between temporal databases and data warehouses have been found. The first closeness between these areas consists in the possibility of a data warehouse redefinition in terms of a bitemporal database. A bitemporal storage mechanism is proposed along this paper. In order to meet this goal, a temporal study of data sources is developed. Moreover, we will show how Object-Oriented temporal data models contribute to add the integration and subject-orientation that is required by a data warehouse.