well you need to compile wget on your server using there instructions and once its installed you simple input something like this to your cron file
You need ssh access and gcc and make access to install software on the server
30 0 * * * /usr/bin/wget --spider
http://www.viperalley.com/classifieds/sendnotice.php
alternatively you can try something like this in your cron file
30 0 * * * /path/to/classifieds/sendnotice.php