You can schedule routine system administration tasks to execute daily, weekly, or monthly by using the crontab command.
Removing files more than a few days old from temporary directories
Executing accounting summary commands
Taking snapshots of the system by using the df and ps commands
Performing daily security monitoring
Running system backups
Rebuilding the catman database for use by the man -k command
Listing files not used during a specific month
Producing monthly accounting reports
For step-by-step instructions on scheduling crontab jobs, see How to Create or Edit a crontab File.