@RaeYcrep You absolutely can. I'm not a debian/ubuntu/raspian user but the following should do what you need:

30 20 * * * root apt-get update && apt-get upgrade -y > /home/your-user-name/updates.log

So at 20:30 run (as root) apt-get update and if successful (&&) run an upgrade with -y (yes to 'are you sure') and write a log file to your home directory.

Make sense?