millseconds to CT date time zone

select to_char(from_tz(CAST (to_date('1970-01-01 00:00:00000','yyyy-mm-dd HH24:MI:SSSSS') +(wl_access_time)/(1000*24*60*60) AS TIMESTAMP),'GMT')at  TIME ZONE 'US/Central','YYYY-MM-DD HH:MI:SS') from wl_servlet_sessions;