Django DateTimeRangeField used with date_hierarchy

[Laurence Sonnenberg]

Hi 

It's great that with 1.11 django.contrib.admin and django.contrib.postgres have brought the ability to use date_hierarchy with fields from other connected tables.

I was wondering if the ability to to create a transform on a given table existed so that fields other than DateField or DateTimeField could be used? For example DateTimeTZRange. Or perhaps it could be done in the postgresql backend?

A transform example might be: 

@admin.register(models.MyModel)

class MyModelAdmin(AdvancedModelAdmin):

    date_hierarchy = 'date_range_to_datetime'

    def date_range_to_datetime(instance):

        """

        Return a datetime from django date range.

        """

        return instance.range.lower

Is there anyone who might have some insight into how this could be done?