Recently, I'm on a server that chrony just barfs on, so my preferred time mechanism doesn't work. Indeed, ntpdate doesn't work as well. Turns out that ntpdate is obsolete (or being obsoleted). After a lot of nonsense, it turns out that running ntpd from the commandline is possible, as long as it is not currently running as a service. First, let's install NTP.
Install and Configure NTP on CentOS
sudo yum -y install ntp sudo service ntpd start sudo chkconfig ntpd on
Stop NTPD and Run Manually on CentOS
sudo service ntpd stop sudo ntpd -gq sudo service ntpd start