In search of the appropriate semantics for the illusion of structures and operations that will meet the needs of a wide class of users interested in a database system supporting temporal views of their data the paper includes both a discussion of many problems that must be addressed and a proposal for an extended relational algebra the informal discussion of issues motivates the proposal to time-stamp the attributes of relations rather than the tuples the proposed algebra incorporates this view with a general treatment of non first-normal-form relations.