I got solution!!!! Followed Toni Rikolla http://stackoverflow.com/questions/13572661/drools-guvnor-how-do-dates-and-times-work

rule "name"

when

                DateRange($endDate: endDate !=null, isValidStructure($endDate.toString));

then

                log.info("..........")

end

function Boolean isValidStructure (String date){

}

From: rules-users-bounces@lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Gopu Shrestha
Sent: Thursday, March 13, 2014 10:54 AM
To: Rules Users List
Subject: [rules-users] compare date structure in WHEN part

I want to compare the date structure YYYY-MM-DD in when part. Can I do this?? any help will be appreciated..

rule "name"

when

                DateRange($endDate: endDate !=null) // $endDate ==” YYYY-MM-DD”  structure

then

                log.info("..........")

end