Most of the time a freshly installed server will automatically set its timezone to be locally orientated, this can be easily changed for user preference.
Finding your Ubuntu systems time can be done with
This will return formated data like
Local time: Fri 2020-01-31 23:41:09 AEDT Universal time: Fri 2020-01-31 12:41:09 UTC RTC time: Fri 2020-01-31 12:41:09 Time zone: Australia/Melbourne (AEDT, +1100) System clock synchronized: yes systemd-timesyncd.service active: yes RTC in local TZ: no
You can see the time and date, the time zone and UTC time and date.
Changing this time require you to know the timezone for the new setting, you can find all the timezones by using:
timedatectl list-timezones | grep -i [zone]
Or to be more specific you can specify the parent zone:
timedatectl list-timezones | grep -i America
Changing the timezone is done by unlinking the local time setting
sudo unlink /etc/localtime
Then adding your zone where the X is:
sudo ln -s /usr/share/zoneinfo/X /etc/localtime
sudo ln -s /usr/share/zoneinfo/America/Chicago /etc/localtime
timedatectl again to confirm the timezone and time has changed.