Ubuntu time not updating
One you are happy after a few days or weeks, you can simply remove the cronjob or disable it with a # at the beginning If you want to keep running it forever but only have one alert per day, let’s say in the morning only, then your cron could be setup like this Then this will only do the timecheck every morning at am. As for the bug, the Ubuntu people really need to sort this out and Fix NTP on Ubuntu as it involves the deprecated ntpdate package which should actually be removed altogether and this is causing a lot of problems for people, most who seem totally unaware of this issue.
UPDATE: The original fix I suggested below is actually NOT the correct solution, I have left it here however to once again show how one can be lead astray by people suggesting stupid solutions on Ubuntu bug reports that actually do NOT fix the problem because those suggesting the solutions don’t understand the actual problem.
I will simply just provide you with the correct fix and it will take you all of a minute or two to fix.
In order to have an accurate time and time synchronization to work properly, the system has to be configured with the correct timezone.
Then it dawned upon me to check NTP as I have been experiencing problems with NTP crashing on both upgrades from Ubuntu 14.0 16.04 and even on fresh 16.04 installs.
I immediately saw what had caused the issue, NTP was not running and the system time had run a good 16 hours into the future causing a major DNSSEC failure on my part.
During the upgrade this NTP bug surfaced and I was not aware of it. When my DNSSEC on bind re-signed a bunch of domain names using DNSSEC it signed them with a date about 16 hours into the future, this resulted in a bunch of signed records in the domains being detected as BOGUS and immediately caused several web sites of mine to go down.
Not immediately knowing the cause of the issue I temporarily disabled DNSSEC on the domains until I could investigate further.