The cron Job is the Linux version of Windows Scheduled Tasks.
To setup a cron you can choose to use the simple setup screen or the advanced screen.
Using advanced the cron will look like this:
0 9 * * * * /home/mysite/cgi-bin/somescript.cgi
For those that wish to use the advanced screen below is a breakdown of the syntax.
Each is a number or wild card where a asterisk ( * ) is the wild card.
Minutes are from 0 to 59
Hours are from 0 to 23
Day is from 1 to 31
Month is from 1 to 12
Day of Week is from 0 to 6
Hours are in 24 hour format so 13 would be 1 PM
Zero = 12 AM
For day of the week zero equals Sunday.
To run a PHP script use either these two methods.
php -q /home/username/public_html/script-name
or
curl -s /dev/null http://websitename/script-name
For a full list of curl usage go to http://curl.haxx.se/docs/manual.html