date group child?

This macro fragment seems a problem …

     <date variable="issued">
       <date-part name="month"/>
       <date-part name="day"/>
       <date-part name="year" prefix=", "/>
     </date>

… that might be easily resolved with a group element:

     <date variable="issued">
       <group suffix=", ">
         <date-part name="month"/>
         <date-part name="day"/>
       </group>
       <date-part name="year" prefix=", "/>
     </date>

But it’s not currently allowed. Should we add it? Or am I missing
something obvious (again!)?

For now I’m just doing:

     <group suffix=", ">
       <date variable="issued">
         <date-part name="month"/>
         <date-part name="day"/>
       </date>
     </group>
     <date variable="issued">
       <date-part name="year"/>
     </date>

Bruce