Hi, In general I am writing rules for events which equal(by attributes values) events can occur any time in consecutive manner(every second). I want to fire rules for matched events only on an hourly bases. In more details: I want to fire a rule when an event is inserted for the first time (not exist yet) OR when an event is inserted and if and only if equal events are already inserted to the working memory BUT the newest of them is at least one hour ago old. What is a reasonable way of writing a rule of that kind, taking events duration will be 24H Thanks -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Drools-Repeated-Event... Sent from the Drools - User mailing list archive at Nabble.com.