How to set default timezone in jasper server report 4.5?

Hi,

        I have install jasper server 4.5 version.Login time any time zone select but generate report time America/New_York timezone apply not any other apply.

Which file set to by default give specific time zone

i have set setenv.bat file

set JAVA_OPTS=%JAVA_OPTS% -Duser.timezone=America/New_York    

but not default set report in display timezone in login time dropdown in selected value time zone display.

please how to use default time set timezone and not use dropdown to select  set timezone please help?

Regards,

Paresh R