date "+%Z%z"

timedatectl status
timedatectl set-timezone Asia/Shanghai
cat /etc/timezone

rpm -ql chrony
# yum install chrony --RHEL7默认已安装chrony，而没有安装ntpd.
# systemctl status chronyd --查看chronyd服务状态
# systemctl enable chronyd --开机启动
chronyc sources - v
chronyc sourcestats -v
sudo netstat -antulp | grep chronyd
chronyc tracking
chronyc makestep