Question: ntpd how to sync time?
Answer: On the Linux machine, log in as root.
Run the ntpdate -u <ntpserver> command to update the machine clock. For example, ntpdate -u ntp-time. ... 
Open the /etc/ntp. conf file and add the NTP servers used in your environment. ... 
Run the service ntpd start command to start the NTP service and implement you configuration changes.