BIP KB:
How To Install NTP Server On Centos 6

Introduction to NTP In this how to we will be installing the NTP (network time protocol) daemon.

We first start by installing ntp:

yum -y install ntp

Now we will configure NTP to start on bootup.

chkconfig ntpd on

Lets now make sure our time is up to date on our server:

ntpdate 0.centos.pool.ntp.org

You should see an output like:

# ntpdate 0.centos.pool.ntp.org
 6 Mar 12:39:40 ntpdate[19226]: step time server 208.68.36.129 offset 2.464276 sec

Now lets start the NTP service:

service ntpd start

Congrats, you have now configured your server as a NTP Server.