Ntp

Supposed to sync clock at startup.

ntp.halfface.se

Print a list of the peers known to the server as well as a summary of their state

ntpq -pn

Verify communication with ntp server.

nc -u -z ntp.ongame.com 123

Set date from ntp server.

ntpdate -u ntp.ongame.com

ntpq -n4c pe -c as -c rl

Troubleshoot ntp

http://www.linuxquestions.org/questions/linux-server-73/ntp-client-error-ntpstat-shows-unsynchronised-749641/