old_contents: import datetime
  
  from django.db import models
  
  
  class TwilioResponse(models.Model):
      date = models.DateTimeField()
      message = models.CharField(max_length=64, primary_key=True)
      account = models.CharField(max_length=64)
      sender = models.CharField(max_length=16)
      recipient = models.CharField(max_length=16)
      status = models.CharField(max_length=16)
  
      def save(self, **kwargs):
          if not self.date:
              self.date = datetime.datetime.now()
          return super(TwilioResponse, self).save(**kwargs)
  
new_contents: from django.db import models
  from django.utils import timezone
  
  
  class TwilioResponse(models.Model):
      date = models.DateTimeField()
      message = models.CharField(max_length=64, primary_key=True)
      account = models.CharField(max_length=64)
      sender = models.CharField(max_length=16)
      recipient = models.CharField(max_length=16)
      status = models.CharField(max_length=16)
  
      def save(self, **kwargs):
          if not self.date:
              self.date = timezone.now()
          return super(TwilioResponse, self).save(**kwargs)
  
subject: Use timezone aware datetime now.