public function toPHP($value, Driver $driver)
    {
        if ($value === null || strpos($value, '0000-00-00') === 0) {
            return null;
        }

        $instance = clone $this->_datetimeInstance;
        $instance = $instance->modify($value);

        if ($this->setToDateStart) {
            $instance = $instance->setTime(0, 0, 0);
        }

        return $instance;
    }