so you want a php script to automatically run on a predefined schedule?
if your server is linux and you have the permissions (u r friends with the admin or you are the admin yourself 🙂 ), set a cronjob.
and, you'll need to have php installed as cgi, too.
as for cronjobs:
http://www.aota.net/Script_Installation_Tips/cronhelp.php4
put the cronjob entries into the www user's crontab (or any user's crontab who has the permissions to run the script). if your script performs database operations and it doesn't work as a cronjob because of missing environment variables, copy these settings from the www user's .bashrc and put them at the top of www's crontab.
