Last spring I made a post on how to set the time source on Windows Server 2008.  Nothing has changed, so no need to rehash it. Just remember, if you need to set a time source for your Windows Domain, run the commands on your Windows Server with the PDC emulator role.

If  you are using Linux, some versions have a command named ntupdate to update against a time server. This command also works in FreeBSD and probably other *nix environments.  The command line  to update against a server (in this case the NRC) is:  ntpdate time.nrc.ca. If you want it to update automatically, add the command as a cronjob. 

Finally, if you are using ntpd, change the servers by editing the /etc/ntp.conf file.  Add the line server time.nrc.ca to add the time server at the NRC.