Qubes OS is an operating system designed for security and nothing breaks the security faster than an unpatched system.
Qubes notifies you when there are updates and you can do them on your own terms. But for the lazy and forgetful people like myself, we prefer the updates to be added automatically. Both in the templates and in the dom0.
This is very easily achieved by using cron. Simply run the following command in the dom0 terminal:
sudo crontab -e
And add inside:
01 01 * * * qubesctl --skip-dom0 --templates state.sls update.qubes-vm 30 01 * * * qubes-dom0-update
Every night, at 01:01 and 01:30 all the templates will be started and updated followed by an update of the dom0.
It should be noted that you need to restart the VMs for them to be updated. A daily reboot can be added in the same way, if you do not shutdown your computer at rest.