Create the script you would like to run from your crontab. A crontab is a list of commands, one per line, that will execute automatically at a given time. Numbers are supplied before each command to specify the execution time. The numbers appear in five fields, as follows:
Day of month 1-31
Day of week 0-6, with 0=Sunday
Use a comma between multiple values, a hyphen to indicate a range, and an asterisk to indicate all possible values. For example:
59 3 * * 5 find / -print | backup_program
This command backs up system files every friday at 3:59am.
0 0 1,15 * * echo "Timesheets due" | mail_user
This command mails a reminder on the 1st and 15th of the month at midnight.
Contab options are:
-e to edit
-l to list
-r Delete the user's file in the crontab directory
If you cannot access crontab, contact you system admin. They can set you up.