protected function isDateAttribute($attribute)
	{
		switch ($attribute)
		{
			case 'LeapYear':
				return (bool) $this->format('L');
				break;
			case 'AmOrPm':
				return $this->format('A');
				break;
			case 'DaylightSavings':
				return (bool) $this->format('I');
				break;
		}

		throw new InvalidArgumentException('The date attribute ['.$attribute.'] could not be found.');
	}