Cron\Validator\CrontabValidator::findReplacements PHP Method

    protected function findReplacements($pattern)
    {
        if (0 !== strpos($pattern, '@')) {
            return $pattern;
        }
        $replace = ['@yearly' => '0 0 1 1 * *', '@annually' => '0 0 1 1 * *', '@monthly' => '0 0 1 * *', '@weekly' => '0 0 * * 0', '@daily' => '0 0 * * *', '@hourly' => '0 * * * *'];
        if (isset($replace[$pattern])) {
            $pattern = $replace[$pattern];
        }
        return $pattern;
    }