I've done scheduled events in terms of storing them for display on a calendar.

Instead of trying to come up with my format for storing the information, I dumped the database out of my palm, and took a look at how they organized things.

These days, I'd probably use iCal, for which there seem to be a number of modules in CPAN. If you wanted to embed the data in something else, there's also hCalendar. Another common standard for scheduling is the Vixie crontab format, as you look to be scheduling commands to trigger ... and there's modules for that, too. (hell, there's modules for cron, even.)