After a change to Daylight Savings Time from standard time, log files display incorrect times. All time entries in logs are behind by one hour compared to the server time, which is correct. This problem indicates that the time zone data in the Java Runtime Environment (JRE) needs to be updated.
Use the Sun TZupdater utility to update the JRE with the latest time zone data. After you run TZupdater, the time stamps in logs will reflect the time on the server.
Sun Developer Network (SDN) Topic