This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
As Bear mentioned, it's much easier to use the OS's scheduler. When calling Java programs from the Windows scheduler, I just wrap the Java program with a small batch script and call that script from the a scheduled task.
On Unix, the combination of wget and cron make this a one liner.