How to set the correct timezone on the server
sudo dpkg-reconfigure tzdata
Remove the old NTP server
Previous versions of Ubuntu used another NTP server.
sudo apt autoremove ntp
How to automatically synchronize the time on the server with a NTP server
The following port must be open for outgoing traffic in the firewall:
UDP port: 123
Check current status:
date
Turn on NTP syncronisation:
sudo timedatectl set-ntp on
The current status of time and time configuration:
timedatectl status
Check the status more in detail via:
systemctl status systemd-timesyncd
Restart the service
sudo systemctl restart systemd-timesyncd.service