today, when you schedule an operation with a date/time in the past, it will work...but it will executed it immediately.  this is a "feature" of quartz, which is used to do the underlying task scheduling.

this is rather dangerous as users wouldn't naturally attempt to do this, i.e. they might have meant to schedule it on a different day but chose something in the past by accident.  instead of failing gracefully and telling them to pick a date in the future we instead happily execute the operation immediately.  schedule operations in the past should be disallowed.