System Settings/Task Scheduler
First define what variables your application needs and their values, then select your application. When this is done you select at which times your application should be run and you're all set.
In KDE4, KCron now is a module which could be found in "system settings > advanced > system section > task scheduler"
In KDE3, KCron can be started using ALT+F2 or K-Menu.
- All the files that are modified are located in the /etc/cron directory where there are numerous files to look at.
- The command-line tool to have a look at the currently installed cron-jobs is crontab -l (that's the letter L).