Ubuntu 18.04 Disable Auto Time Updates

Firstly disable automatic times

timedatectl set-ntp off

Then simple set the time manualy, or the time itself will still automatically update.

sudo date --set "21 Dec 2020 14:42:00"

To re-enable automatic date/time updates use

timedatectl set-ntp on

To check the status use

timedatectl status

You should see something like below. the three ‘no’ mean it’s disabled.

Local time: Mon 2020-12-21 15:00:02 SAST
Universal time: Mon 2020-12-21 13:00:02 UTC
RTC time: Mon 2020-12-21 12:56:50
Time zone: Africa/Johannesburg (SAST, +0200)
System clock synchronized: no
systemd-timesyncd.service active: no
RTC in local TZ: no