hehe yes.. it was a typo.. I'm sleepy...
So if you want to get the start dates and end dates you can use your approach of storing the information somewhere with the org.drools.event.process.ProcessEventListener and then query that information. I'm not sure if adding that as process varible will be useful, do you need that information inside your process or you want to show that information in an administration console or something like that?
Cheers