Crontab
From Linuxintro
crontab is a configuration file in the /etc folder that tells the cron daemon when to perform what commands. It can look like this:
# Sample crontab file */10 * * * * fetchmail -p pop3 -u 612696 -v pop.gmx.net
A line starting with a # is a comment. The other line in this example follows the form
<minute> <hour> <day of month> <month> <day of week> [user] <command>
where [user] is optional.
Examples
Run the command fetchmail every day at 10 minutes past 1:
10 1 * * * fetchmail
Run the command fetchmail every day and hour at 10 minutes past the hour:
10 * * * * fetchmail
Run the command fetchmail every 10 minutes:
*/10 * * * * fetchmail
