Off the bat, the Ubuntu server is installed with ntpdate.
At the command line enter “ntpdate ntp.ubuntu.com” (or some other ntp source)
You’ll get something like this back:
“7 Feb 22:29:34 ntpdate: step time server 126.96.36.199 offset 40.918237 sec”
ntpdate pulls the time from an ntp server, or more than one. It then adjusts the clock on the server.
The Ubuntu Linux distro runs ntpdate once at boot time. You can also enter it as a daily cron job.
See also NTP FAQ.