actually the easiest way is to use wget, you just use wget (installed by default on redhat linux) and setup the cron job that way, do a yahoo.com search for running php page with cron wget, and there will be examples out there, depending on how they are doing it, there are different ways to do it, you can do it command line, you just edit crontab -e with vi or if they are at the physical machine, there is something called task scheduler, where they can set the cron to run, they need to set it up with apache as running it to make it work