AFAIK, java Date type is independent from Timezone which means that it represents specific moment of time as long typed value. I found really weird thing here. This is the original value i tried to insert. (http-0.0.0.0-9080-4) 1352955600000 <-- long integer. (http-0.0.0.0-9080-4) Thu Nov 15 00:00:00 EST 2012 <-- User Friendly Format. After i finished inserting into Oracle 11g database, the value has changed! (http-0.0.0.0-9080-4) 1352952000000 (http-0.0.0.0-9080-4) Wed Nov 14 23:00:00 EST 2012 How could this happen?? The more weird thing is it only happens specific environments such as Jboss. I'm currently using below environments. java 1.6 ibatis 2.34 jboss-5.1 (server) tomcat 6.0 (local) oracle 11g Is there anybody who can give me a clue or link to be helpful? it really bugging me!!