old_contents: import json
  
  from website.util.permissions import reduce_permissions
  
  from admin.users.serializers import serialize_simple_node
  
  
  def serialize_node(node):
      embargo = node.embargo
      if embargo is not None:
          embargo = node.embargo.end_date
  
      return {
          'id': node._id,
          'title': node.title,
          'public': node.is_public,
          'parent': node.parent_id,
          'root': node.root._id,
          'is_registration': node.is_registration,
          'date_created': node.date_created,
          'withdrawn': node.is_retracted,
          'embargo': embargo,
          'contributors': [serialize_simple_user_and_node_permissions(node, user) for user in node.contributors],
          'children': map(serialize_simple_node, node.nodes),
          'deleted': node.is_deleted,
          'pending_registration': node.is_pending_registration,
          'creator': node.creator._id,
          'spam_status': node.spam_status,
          'spam_pro_tip': node.spam_pro_tip,
          'spam_data': json.dumps(node.spam_data, indent=4),
          'is_public': node.is_public,
      }
  
  
  def serialize_simple_user_and_node_permissions(node, user):
      return {
          'id': user._id,
          'name': user.fullname,
          'permission': reduce_permissions(node.get_permissions(user))
      }
  
new_contents: import json
  
  from website.util.permissions import reduce_permissions
  
  from admin.users.serializers import serialize_simple_node
  
  
  def serialize_node(node):
      embargo = node.embargo
      if embargo is not None:
          embargo = node.embargo.end_date
  
      return {
          'id': node._id,
          'title': node.title,
          'public': node.is_public,
          'parent': node.parent_id,
          'root': node.root._id,
          'is_registration': node.is_registration,
          'date_created': node.date_created,
          'withdrawn': node.is_retracted,
          'embargo': embargo,
          'contributors': [serialize_simple_user_and_node_permissions(node, user) for user in node.contributors],
          'children': map(serialize_simple_node, node.nodes),
          'deleted': node.is_deleted,
          'pending_registration': node.is_pending_registration,
          'registered_date': node.registered_date,
          'creator': node.creator._id,
          'spam_status': node.spam_status,
          'spam_pro_tip': node.spam_pro_tip,
          'spam_data': json.dumps(node.spam_data, indent=4),
          'is_public': node.is_public,
      }
  
  
  def serialize_simple_user_and_node_permissions(node, user):
      return {
          'id': user._id,
          'name': user.fullname,
          'permission': reduce_permissions(node.get_permissions(user))
      }
  
subject: Add date_registered to node serializer