Temporal data type and temporal relation operations

This paper discuses the presentation and the operation of temporal data from the point of view of data types. It presents the operation of temporal data as data-value operation and time-value operation. It extends the relational algebra operators to carry out temporal operations. These operations are self-contained in some restriction conditions. Temporal data type is regarded as a standard data types to users in a system, and temporal data are managed completely by the system. The users can make use of temporal data type expediently, and accord with customs of user.