“Have you ever wandered near your Linux box in the middle of the
night, only to discover the hard disk working furiously? If you
have, or just want a way for some task to occur at regular
intervals, cron is the answer.
“The cron daemon, crond, packaged with most Linux
distributions, controls scheduling of regularly occurring
jobs.”
“I have provided a brief introduction to the cron facility, a
typical part of Linux and other UNIX operating systems. It will
provide a starting point for time-related work you want your Linux
system to perform. In brief, if you want to schedule repetitive
tasks so as not to type the same commands again and again, use
cron.”