ntpdate failing to synchronise clock.

My client timing was ahead of the NTP Server by 15 hours. When I did a

# ntpdate -q 0.centos.pool.ntp.org

The synchronization did not work.

To force the client to synchronise no matter how absurd the time differences, you have to use a "-b" parameter.

# ntpdate -b 0.centos.pool.ntp.org