Install NTPd and Configure NTP server for time adjustment.
[1] Install NTPd.

[root@localhost ~]# yum -y install ntp
[root@localhost ~]# vi /etc/ntp.conf
# line 18: add the network range you allow to receive requests
restrict 10.0.0.0 mask 255.255.255.0 nomodify notrap
# change servers for synchronization
#server 0.centos.pool.ntp.org iburst
#server 1.centos.pool.ntp.org iburst
#server 2.centos.pool.ntp.org iburst
#server 3.centos.pool.ntp.org iburst
server 2.vn.pool.ntp.org iburst
server 2.asia.pool.ntp.org iburst
server 0.asia.pool.ntp.org iburst
[root@localhost ~]# systemctl start ntpd
[root@localhost ~]# systemctl enable ntpd

[2] If Firewalld is running, allow NTP service. NTP uses 123/UDP

[root@localhost ~]# firewall-cmd --add-service=ntp --permanent
success
[root@localhost ~]# firewall-cmd --reload
success

[3] Verify it works normally like follows

[root@localhost ~]# ntpq -p