DTV12 — DTV Issue: Inconsistency between designs of "Duration Value" and "Time Coordinate

The concepts 'time coordinate' and 'duration value' serve similar purposes: one defines how time points are represented in terms of calendars, and the other addresses how durations are represented in terms of measurement units. 'Time Coordinate' is defined as a "representation of a time point" in clause 10.6.1, which is fine. In contrast, 'duration value' is defined in clause 9.2 as being either an 'atomic' or 'compound' duration value, with the former having a number and a unit. So 'duration value' is NOT a representation.

I believe the final design of 'time coordinate' was decided late in the FTF phase after considerable discussion – and the FTF overlooked converting 'duration value' to a similar design. This should be fixed

The RTF agrees that neither a duration value nor a time coordinate is a ‘representation’ in the SBVR sense. Each can have more than one ‘expression’. Rather, the instances of both are “conceptual structures of meaning”. A duration value is the instantiation of a reference scheme for duration. It is a structure of meaning that is interpreted as a definite description of a duration. A time coordinate is a structure of meaning that ‘indicates’ (is interpreted as) a concept that is a category of time interval. The text and the UML model are revised to state these characterizations.
A reference scheme for the concept ‘time point’ that is actually used in Gregorian calendar time coordinates is (time point kind, index), and this is added to the reference schemes for time point.
Issue 19547 identifies additional problems with the same sections of clause 10.6. It modifies many of the same diagrams and entries. Therefore the revised text of this issue resolution is merged with that of Issue 19547.