  from django.utils.translation import ugettext_lazy as _
  from django.utils.datastructures import SortedDict
  
  from rest_framework import ISO_8601
  from rest_framework.compat import timezone, parse_date, parse_datetime, parse_time
  from rest_framework.compat import BytesIO
  from rest_framework.compat import six
  from rest_framework.compat import smart_text
  from rest_framework.settings import api_settings
  
 
</s> remove     format = ', '.join(formats).replace(ISO_8601, 'YYYY-MM-DDThh:mm[:ss[.uuuuuu]][+HHMM|-HHMM|Z]')
 </s> add     format = ', '.join(formats).replace(ISO_8601,
             'YYYY-MM-DDThh:mm[:ss[.uuuuuu]][+HHMM|-HHMM|Z]')
from rest_framework.compat import (timezone, parse_date, parse_datetime,
                                   parse_time)
  from django.utils.translation import ugettext_lazy as _
  from django.utils.datastructures import SortedDict
  
  from rest_framework import ISO_8601
from rest_framework.compat import (timezone, parse_date, parse_datetime,
                                   parse_time)
  from rest_framework.compat import BytesIO
  from rest_framework.compat import six
  from rest_framework.compat import smart_text
  from rest_framework.settings import api_settings
  
keep keep keep keep replace keep keep keep keep keep
 Added humanized field names and types 
rest_framework/fields.py