The December 2013 version of the Quality Data Model (QDM) no longer includes definitions for relative timings or operators. The QDM references the Measure Authoring Tool (MAT) user guide as the definition for these operators. Although the QDM may not be the ideal location for operators and relative timings, it is a better alternative to the MAT User Guide. There is also overlap between the relative timings and operators that would be defined in the QDM and the specifications used to express the measures, namely HQMF and HeD. Reconciliation also needs to be done to align the operators defined by the QDM and the specifications. However, allowing the specifications to directly define the set of operators and their definitions would tightly couple the definition of the measure logic to specific specifications. Therefore, having the definitions of operators included in the QDM is likely the best alternative, maintaining the understanding that there needs to be a viable path to map the QDM operators to the associated specifications.