Just a quick reference for setting up your Gentoo server to get its time from an NTP server either local or on the Internet.
Get NTP onto the machine
emerge --ask -jv ntp
Edit the NTP config
Comment out the servers that you do not need and add your own, the address I have added below is a pool of servers so we only need to set one entry you could do this internally by creating a DNS round robin type situation or just specify three seperate entries.
Edit the NTP entry in conf.d
Add the below lines
NTPDATE_CMD="ntpdate" NTPDATE_OPTS="-b au.pool.ntp.org"
Now that it is configured start the service and make sure that it starts in your default run level.
/etc/init.d/ntp-client start ; rc-update add ntp-client default