crontab 并没有博主所说的的详细情况
crontab -l
*/20 * * * * /usr/sbin/ntpdate pool.ntp.org > /dev/null 2>&1
30 2 * * 1 /usr/local/python/bin/certbot renew --renew-hook "/etc/init.d/nginx reload"
crontab -l
*/20 * * * * /usr/sbin/ntpdate pool.ntp.org > /dev/null 2>&1
30 2 * * 1 /usr/local/python/bin/certbot renew --renew-hook "/etc/init.d/nginx reload"