This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Lots of ways; doing a search of these fora will reveal other threads about the same subject. Try a java.util.Timer or a javax.swing.Timer, or repeatedly querying Calender objects for the time, or anacron or cron, or Windows task scheduler. As I said, a search will reveal many possible solutions.