old_contents: import datetime
  
  from django.db import models
  from django.contrib.auth.models import User
  from django.db.models.signals import post_save
  
  class Reminder(models.Model):
      user = models.ForeignKey(User, unique=True)
      last_reminder = models.DateTimeField()
      next_reminder = models.DateField()
      wday = models.IntegerField()
      active = models.BooleanField()
  
  def add_reminder(sender, **kwargs):
      instance = kwargs.get('instance', None)
      try:
          reminder = Reminder.objects.get(user=instance)
      except Reminder.DoesNotExist:
          now = datetime.datetime.now()
          next = now + datetime.timedelta(days=7)
  
          reminder = Reminder()
          reminder.user = instance
          reminder.last_reminder = now
          reminder.next_reminder = next
          reminder.wday = now.timetuple().tm_wday
          reminder.active = True
          reminder.save()
  
  post_save.connect(add_reminder, sender=User)
  
  
new_contents: import datetime
  
  from django.db import models
  from django.contrib.auth.models import User
  from django.db.models.signals import post_save
  
  _ = lambda x: x
  
  # Reference: http://docs.python.org/library/time.html
  # - tm_wday => range [0,6], Monday is 0
  MONDAY = 0
  TUESDAY = 1
  WEDNESDAY = 2
  THURSDAY = 3
  FRIDAY = 4
  SATURDAY = 5
  SUNDAY = 6
  
  DAYS = (
      (MONDAY, _('Monday')),
      (TUESDAY, _('Tuesday')),
      (WEDNESDAY, _('Wednesday')),
      (THURSDAY, _('Thursday')),
      (FRIDAY, _('Friday')),
      (SATURDAY, _('Saturday')),
      (SUNDAY, _('Sunday'))
  )
  
  class Reminder(models.Model):
      user = models.ForeignKey(User, unique=True)
      last_reminder = models.DateTimeField()
      next_reminder = models.DateField()
      wday = models.IntegerField(choices=DAYS, verbose_name="Day",
                                 default=MONDAY)
      active = models.BooleanField()
  
  def add_reminder(sender, **kwargs):
      instance = kwargs.get('instance', None)
      try:
          reminder = Reminder.objects.get(user=instance)
      except Reminder.DoesNotExist:
          now = datetime.datetime.now()
          next = now + datetime.timedelta(days=7)
  
          reminder = Reminder()
          reminder.user = instance
          reminder.last_reminder = now
          reminder.next_reminder = next
          reminder.wday = now.timetuple().tm_wday
          reminder.active = True
          reminder.save()
  
  post_save.connect(add_reminder, sender=User)
  
  
subject: Set available options for weekday field of reminder's model