yes it does need to be fired from a page on a website (from a html or PHP file). You can also fire it via a cron job.
There are lots more details here: http://members.dwalker.co.uk/forum/viewtopic.php?f=1&t=919
BTW - hope you like phpjobscheduler, I first created it over 10 years ago: http://www.phpjobscheduler.co.uk/demo/readme.html#history