Stefano Bragaglia wrote Agreed, one may want to write both qualitative ( A after B ) and quantitative constraints ( A.time > x ) on an event. While this is possible when the even timestamp is assigned externally, this is very hard to do with the fusion-managed timestamp. Unfortunately, what you propose won't work, since that particular configuration (setting a @timestamp field) would break the assumption of immutable events. We would need something like: //operator-like, even better with implicit unification Event( this happensAt $t ) // timestamp Event( this lasts $d ) // duration //accessor-like Event( $t := happensAt, lasts > 100 ) Probably this needs to be taken to the dev channel or to the jira feature requests Best Davide -- View this message in context: http://drools.46999.n3.nabble.com/Drools-Fusion-Accessing-Events-time-rea... Sent from the Drools: User forum mailing list archive at Nabble.com.