Use cron. Cron essentially acts like a running process that fires off things when necessary, (yes, I know that this isn't strictly true...) why reinvent the wheel?

That being said, cron does have a few gotchas:
* Funny things happen when DST kicks in or out (you can search perlmonks for my recent thread on this.)
* Scripts run from cron have a pristine environment, without a normal path env var etc, etc. You must keep this in mind when coding your scripts.

Editing a crontab file to schedule your scripts is not at all difficult. Consult man crontab for details.