Another way to do it is with a cron job. There are several frontends available but none are as complete as the command line. Cron lets you schedule times for things to run or stop, even activate at boot. One thing to note is that if it requires sudo powers you type sudo crontab -e and for normal launches simply crontab -e.
For example, if I add
30 5 30 3 apt-get install calligraflow dia -y --force-yes --fix-mi
to sudo crontab -e the computer will download and install calligraflow and dia at 5:30AM the 30th of march.