While almost all temporal query languages support temporal projection, the flexibility of that support varies greatly.
In some languages, temporal projection is implicit and is based the intersection of the times of the underlying facts. Other languages have special constructs to specify temporal projection.
The name has already been used extensively in the literature (+E3). It derives from the retrieve clause in Quel as well as the SELECT clause in SQL, which both serve the purpose of the relational algebra operator projection, in addition to allowing the specification of derived attribute values.