If you're on a Unix system of some sort and have permission. 'cron' (man cron) would be the way to go, as it was designed exactly for this task.

If you're on a Windows box, they have a cron like 'Scheduler' that should server the same function.

HTH

/\/\averick
perl -l -e "eval pack('h*','072796e6470272f2c5f2c5166756279636b672');"