Standardize on get_default_time_display

cms/djangoapps/contentstore/views/component.py

@@ -220,7 +220,7 @@ def edit_unit(request, location):
         'section': containing_section,
         'create_new_unit_template': Location('i4x', 'edx', 'templates', 'vertical', 'Empty'),
         'unit_state': unit_state,
-        'published_date': item.cms.published_date.strftime('%B %d, %Y') if item.cms.published_date is not None else None,
+        'published_date': get_default_time_display(item.cms.published_date) if item.cms.published_date is not None else None
     })