having the wrong date and time in the system can be disastrous as many applications will be using the system date and time. It is therefore very important to have the right date and time.
yum install ntp chkconfig ntp on ntpdate pool.ntp.org service ntpd start
You can add the ntpdate command to cron to automate the syncing process. Another easy way is to do it in the GUI, if you have it.