Time Synchronization on Virtual Machines

There are many recommended methods of keeping a VMWare virtual machine's clock in sync with the host clock, like this one.

However, there are cases when the recommended methods simply don't work. Not even enabling the NTP protocol works sometimes. In these cases, as root add the following cron job (by typing crontab -e (as root)):

0,15,30,45 * * * * /usr/sbin/ntpdate clock.redhat.com 1> /dev/null
    

This will correct the time every 15 minutes. While this is not the ideal solution, it does work.