Currently a calendar timer being created out of a ScheduleExpression which doesn't have any future timeouts, fails with:

java.lang.IllegalArgumentException: No timeout in future from now Wed Aug 18 19:59:56 SGT 2010 Invalid schedule expression: javax.ejb.ScheduleExpression@4803581
at org.jboss.ejb3.timerservice.mk2.TimerServiceImpl.createCalendarTimer(TimerServiceImpl.java:433)
at org.jboss.ejb3.timerservice.mk2.TimerServiceImpl.createCalendarTimer(TimerServiceImpl.java:166)
at org.jboss.ejb3.timerservice.mk2.TimerServiceImpl.createCalendarTimer(TimerServiceImpl.java:154)

We shouldn't be failing the timer creation for such schedules. Instead, the timer creation must pass and any invocations on getNextTimeout() or other such methods should throw an exception as mandated by the spec.