SSH into the server.
Check the status of the ntpd service
service ntpd status
Is ntpd running ?
if not start the service and ntpd will start checking in for time updates.
If you want to update time now
service ntpd stop
ntpdate -s 0.centos.pool.ntp.org
date
service ntpd start
if you cant connect to your ntp server you should see the time change.
