gistfile1.py

class UTCTimeAuditedModel(models.Model):
    """
    Abastract model providing UTC time auditing.

    Adds two fields `utc_created_at` set on first save of the instance, and
    `utc_updated_at` updated on every item save to the current utc datetime
    """
    utc_created_at = models.DateTimeField(editable=False, verbose_name=_(u"created at (utc)"))
    utc_updated_at = models.DateTimeField(editable=False, verbose_name=_(u"updated at (utc)"))

    class Meta:
        abstract = True

    def save(self, force_insert=False, force_update=False):
        utcnow = datetime.datetime.utcnow()
        if not self.pk:
            self.utc_created_at = utcnow
        self.utc_updated_at = utcnow
        return super(UTCTimeAudited, self).save(force_insert, force_update)