If you are interested in scheduling tasks in JBoss AS, there are few pointers that you should look at and choose:
1) Quartz Scheduler
The EJB3 subsystem has quartz integration that you may want to utilize.
2) Use java.util.Timer
You will need to create your own instances of timer tasks in your application.
3) JBoss Scheduler
Section 10.7 and 10.8 of http://docs.jboss.org/jbossas/docs/Server_Configuration_Guide/4/html/index.html