old_contents: from django.db import models
  
  from collections import defaultdict
  import datetime
  
  from helpers import parse
  from forms import TimedeltaFormField
  
  SECS_PER_DAY = 60*60*24
  
  # TODO: Figure out why django admin thinks fields of this type have changed every time an object is saved.
  
  # Define the different column types that different databases can use.
  COLUMN_TYPES = defaultdict(lambda:"char(20)")
  COLUMN_TYPES["django.db.backends.postgresql_psycopg2"] = "interval"
  COLUMN_TYPES["django.contrib.gis.db.backends.postgis"] = "interval"
  
  class TimedeltaField(models.Field):
      """
      Store a datetime.timedelta as an INTERVAL in postgres, or a 
      CHAR(20) in other database backends.
      """
      __metaclass__ = models.SubfieldBase
      _south_introspects = True
      
      description = "A datetime.timedelta object"
      
      def to_python(self, value):
          if (value is None) or isinstance(value, datetime.timedelta):
              return value
          if isinstance(value, int):
              return datetime.timedelta(seconds=value)
          if value == "":
              return datetime.timedelta(0)
          return parse(value)
      
      def get_prep_value(self, value):
          if (value is None) or isinstance(value, (str, unicode)):
              return value
          return str(value).replace(',', '')
          
      def get_db_prep_value(self, value, connection=None, prepared=None):
          return self.get_prep_value(value)
          
      def formfield(self, *args, **kwargs):
          defaults = {'form_class':TimedeltaFormField}
          defaults.update(kwargs)
          return super(TimedeltaField, self).formfield(*args, **defaults)
      
      def value_to_string(self, obj):
          value = self._get_val_from_obj(obj)
          return unicode(value)
      
      def get_default(self):
          """
          Needed to rewrite this, as the parent class turns this value into a
          unicode string. That sux pretty deep.
          """
          if self.has_default():
              if callable(self.default):
                  return self.default()
              return self.get_prep_value(self.default)
          if not self.empty_strings_allowed or (self.null):
              return None
          return ""
          
      def db_type(self, connection):
          return COLUMN_TYPES[connection.settings_dict['ENGINE']]
  
  
  
new_contents: from django.db import models
  
  from collections import defaultdict
  import datetime
  
  from helpers import parse
  from forms import TimedeltaFormField
  
  # TODO: Figure out why django admin thinks fields of this type have changed every time an object is saved.
  
  # Define the different column types that different databases can use.
  COLUMN_TYPES = defaultdict(lambda:"char(20)")
  COLUMN_TYPES["django.db.backends.postgresql_psycopg2"] = "interval"
  COLUMN_TYPES["django.contrib.gis.db.backends.postgis"] = "interval"
  
  class TimedeltaField(models.Field):
      """
      Store a datetime.timedelta as an INTERVAL in postgres, or a 
      CHAR(20) in other database backends.
      """
      __metaclass__ = models.SubfieldBase
      _south_introspects = True
      
      description = "A datetime.timedelta object"
      
      def to_python(self, value):
          if (value is None) or isinstance(value, datetime.timedelta):
              return value
          if isinstance(value, int):
              return datetime.timedelta(seconds=value)
          if value == "":
              return datetime.timedelta(0)
          return parse(value)
      
      def get_prep_value(self, value):
          if (value is None) or isinstance(value, (str, unicode)):
              return value
          return str(value).replace(',', '')
          
      def get_db_prep_value(self, value, connection=None, prepared=None):
          return self.get_prep_value(value)
          
      def formfield(self, *args, **kwargs):
          defaults = {'form_class':TimedeltaFormField}
          defaults.update(kwargs)
          return super(TimedeltaField, self).formfield(*args, **defaults)
      
      def value_to_string(self, obj):
          value = self._get_val_from_obj(obj)
          return unicode(value)
      
      def get_default(self):
          """
          Needed to rewrite this, as the parent class turns this value into a
          unicode string. That sux pretty deep.
          """
          if self.has_default():
              if callable(self.default):
                  return self.default()
              return self.get_prep_value(self.default)
          if not self.empty_strings_allowed or (self.null):
              return None
          return ""
          
      def db_type(self, connection):
          return COLUMN_TYPES[connection.settings_dict['ENGINE']]
  
  
  
subject: Remove unused constant.