Automatic server updates & reboots

A cron job can take care of that:

echo "0 3 * * * (apt-get update & apt-get -y upgrade && apt autoclean -y && apt autoremove -y)" >> mycron && \
echo "0 4 * * 4 reboot" >> mycron && \
crontab -u root mycron && \
rm mycron && \
crontab -l

Make sure you have the right timezone set:

timedatectl set-timezone Europe/Berlin

To check the status and list the timezones:

timedatectl status
timedatectl list-timezones