Yup. I'm not sure it if's just debian/ubuntu, or it's for all of Linux (I assume the latter), but it's a scheduling daemon. Right now, here's root's crontabs.
30 22 * * * echo "Starting dist-upgrade: $(date)" >> /tmp/update.log && /usr/bin/apt-get update -y && /usr/bin/apt-get dist-upgrade -y
From the
Ubuntu Wiki Page about cron, it says that the first five spaces (here: "30 22 * * *") specify, in order, the *minute*, *hour*, *day of month*, *month* and *day of week*.
So I have these tasks scheduled to occur at 10:30 (2230 military time) each night:
Make a note about system upgrade in /tmp/update.log
Get list of latest updates (apt-get update -y)
Download + install them (apt-get dist-upgrade -y)