code: def diff(self, dt=None, abs=True):
          
          if dt is None:
              dt = self.now(self.tz)
  
          return Period(self, dt, absolute=abs)
docs: Returns the difference between two DateTime objects represented as a Duration.
  
          :type dt: DateTime or None
  
          :param abs: Whether to return an absolute interval or not
          :type abs: bool
  
          :rtype: Period