nice clean way is to create the /etc/inet/ntp.conf file with the following contents:
server ip_of_timeserver
server ip_of_timeserver
server ip_of_timeserver
logfile /var/ntp/ntp.log
driftfile /var/ntp/ntp.drift
server 127.127.1.0
fudge 127.127.1.0 stratum 8
replacing ip_of_timeserver with the IP of the server or servers (make 3 the same if theres just 1).
then stop and start /etc/init.d/xntpd
you can monitor the progress by using ntptrace or by using the interactive utility ntpq (use show peers).
using ntptrace, if it ever shows as a "stratum 16" server, it means that it is no-longer timesynched, and is broken. The stratum number should always be +1 of the upstream timeserver.
give it a while to synch though, it takes a few minutes.