Michael, Just an important note, that sometimes is overlooked by users: *** Inline evals and return value predicates MUST be time constant *** It means that an inline eval() must return the exact same value if it is executed now, or in 5 minutes from now, or whatever. So, it is not advisable for you to write the constraint as you did. The correct way would be to use a top level eval() that does not suffer from the same restriction: MyFact( $value : value ) eval( $value.before(DateHelper.getModifiedDate(-6, "MONTHS"))) The use of a non-time-constant inline eval (or return value predicates) causes unpredictable behavior in the engine. []s Edson 2008/5/7 Michael B. <michael.bain(a)mckesson.com&gt;: > > I dont know if this is still outstanding since the original post seems to > have disappeared, but this is what I did during my proof of concept that > I > am going through: > > In a helper class (i.e. DateHelper) I had this method: > > public static Date getModifiedDate(int amount, String unit) { > Calendar cal = Calendar.getInstance(); > cal.setTime(getNow()); > BusinessObject.stripTime(cal); > > int calUnit = Calendar.DAY_OF_YEAR; > > if (UNIT_MONTHS.equals(unit)) > calUnit = Calendar.MONTH; > else if (UNIT_YEARS.equals(unit)) > calUnit = Calendar.YEAR; > > cal.add(calUnit, amount); > return cal.getTime(); > } > > Then in my rule it would be like this: > > MyFact( eval( value.before(DateHelper.getModifiedDate(-6, "MONTHS")))) > > Hope that helps. > > ----- > Drools Noob since 5/2008 > -- > View this message in context: > http://www.nabble.com/Re%3A-Date-arithmetic-in--%C3%A2%C2%80%C2%9Cwhen%C3... > Sent from the drools - user mailing list archive at Nabble.com. > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > -- Edson Tirelli JBoss Drools Core Development Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users

Hi, you shouldn't put part of the "if" or "when" part after the "then". Put all conditions after the "when" so the rule engine will evaluate them. I guess you mean to write something like (although I haven't tested this): rule "ITR Discard" when req : LowFareRequest( $reqTime : requestedDeparture.time) itr : AirItinerary( discarded == false ) flight : Flight( departure.time - 2 * 3600000 < $reqTime, departure.time + 4 * 3600000 > $reqTime) then System.out.println("discard true"); end Christine _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users