How to do it...

Open the models.py file in your myprojects.apps.core package, and insert the following content there:

# myproject/apps/core/models.py
from django.db import models
from django.utils.translation import gettext_lazy as _


class CreationModificationDateBase(models.Model):
    """
    Abstract base class with a creation and modification date and time
    """

    created = models.DateTimeField(
        _("Creation Date and Time"),
        auto_now_add=True,
    )

    modified = models.DateTimeField(
        _("Modification Date and Time"),
        auto_now=True,
    )

    class Meta:
        abstract = True