public function getDateType($key, $format = 'Y-m-d')
	{
		if (!strlen($format))
		{
			$format = 'Y-m-d';
		}
		
		if ($this->exists($key) and $this->get($key))
		{
			return date($format, strtotime($this->get($key)));
		}
		
		return null;
	}