Django model DateTimeField set auto_now_add format or modify the serializer

I have this field in my model:

createdTime = models.DateTimeField(_('Creation date'), help_text=_('Date of the creation'),
                                   auto_now_add=True, blank=True)

And it is saved with this format:

2016-05-18T15:37:36.993048Z

So I would like to convert it to this format DATE_INPUT_FORMATS = ('%d-%m-%Y %H:%M:S') but I dont know where to do it.

I have a simple serializer class, could I override it to modify the format? or maybe create a get_date() model method?

class ObjectSerializer(serializers.ModelSerializer):
    """
    Serializer for object.
    """
    class Meta:
        model = Object

My settings:

DATETIME_FORMAT = '%d-%m-%Y %H:%M:%S'

USE_I18N = True

USE_L10N = False

USE_TZ = False

Answer

Set DATETIME_FORMAT in your settings.py as specified here.

The default formatting to use for displaying datetime fields in any part of the system. Note that if USE_L10N is set to True, then the locale-dictated format has higher precedence and will be applied instead

The date part of your settings.py should afterwards look like so:

DATETIME_FORMAT = '%d-%m-%Y %H:%M:%S' 
USE_L10N = False
USE_TZ = False # if you plan to disable timezone support

Alternatively, you can manually change formats after retrieval by doing:

import datetime

datetime_str = '2016-05-18T15:37:36.993048Z'
old_format = '%Y-%m-%dT%H:%M:%S.%fZ'
new_format = '%d-%m-%Y %H:%M:%S'

new_datetime_str = datetime.datetime.strptime(datetime_str, old_format).strftime(new_format)
print(new_datetime_str)
#'18-05-2016 15:37:36'

This conversion can be added to your serializer or model as your proposed get_date() method