The Network Time Protocol daemon (ntpd) program is a Linux operating system daemon. It sets and maintains the system time of day in synchronism with time servers (Mills).You need to configure ntpd via /etc/ntp.conf configuration file. The file is well documented and you easily configure it.he Network Time Protocol daemon (ntpd) program is a Linux operating system daemon. It sets and maintains the system time of day in synchronism with time servers (Mills).