DTV11 — DTV Issue: Clause 11 depends on clause 9

Clause 11, Gregorian Calendar, defines concepts 'year value', 'years duration value set', 'month value', and 'months duration value set' – all of which are dependent upon concepts defined in clause 9, 'Duration Values'. But (1) the 'Gregorian Calendar Vocabulary' does not include the 'Duration Values Vocabulary', and (2) figure 7.3 fails to show the dependency. Both of these should be fixed.

As described. The included calendar references in the Gregorian Calendar Vocabulary are corrected. Introductory text is also added to the beginning of Clause 11.