With wide acceptance of the data warehousing technology, researchers are proposing data models and development methodologies. While they recognize time as an important dimension, the suggested modeling is largely ad-hoc and experience driven. On the other hand, the research in temporal databases since mid-eighties has made many fundamental contributions, and has created a formal and powerful framework both at modeling and technology levels.In this paper, we review the temporal issues in data warehousing, and propose a temporal model for data warehouses. The concepts of states, events, object lifecycles, temporal constraints and temporal operators are used to enrich the data model for warehousing. We propose a logical data warehouse design step that takes into account temporal characteristics of data, followed by a physical design step to address efficient storage and access. We also propose an integrated framework of applications and data warehouse, where the applications are made 'warehouse aware' for pushing complete and consistent data into the data warehouse. We also identify some important issues for future investigations.