At first set time using tzsetup

At second need to add the next line to /etc/rc.conf file

ntpdate_enable="YES"

The third thing is to edit /etc/ntp.conf by adding lines

server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org
server pool.ntp.org
driftfile /var/db/ntp.drift

Reboot and time should be set automatically