You'll need to run your script via a scheduler like cron (a UNIX daemon, but available for Windows, which has its own scheduler called "Task Scheduler", IIRC), or set up your program as a service (in Windows) or a daemon (*nix). If you choose to do the latter, have a look at the thread "Install a perl script as a Win NT/2000/XP service.". I would strongly recommend you set up your script using the scheduler.