How to set time and date using ntpd (CentOS)?
If ntpd is already running, then the time should already be set correctly.
If you didn’t install ntpd, then:
# yum install ntp
# chkconfig ntpd on
# ntpdate pool.ntp.org
# service ntpd start
If ntpd is running, but the time is way off, then you can force an update:
# service ntpd stop
# ntpdate pool.ntp.org
# service ntpd start