This took me a little while to find the answer to…Hopefully this get indexed well for other’s Google searches…
How does Ubuntu 16.04 LTS and later handle NTP?
16.04 LTS time sync appears to be handled by sytemd specifically “timedatectl”
timedatectl status Local time: Wed 2016-11-30 17:45:18 CST Universal time: Wed 2016-11-30 23:45:18 UTC RTC time: Sun 2016-12-04 06:50:39 Time zone: America/Chicago (CST, -0600) Network time on: yes NTP synchronized: yes RTC in local TZ: no
More info here: Time Synchronisation with NTP