oracle time

 select TO_DATE('01/01/1970', 'MM/DD/YYYY') + r.starttime / 86400000 +
                TO_NUMBER(SUBSTR(TZ_OFFSET(sessiontimezone), 1, 3)) / 24
                 into startdate
 select TO_DATE('01/01/1970', 'MM/DD/YYYY')  from dual;
 
select '86400000' / 86400000 + TO_NUMBER(SUBSTR(TZ_OFFSET(sessiontimezone), 1, 3)) / 24 from dual;

select TO_NUMBER('01/01/1970', 'MM/DD/YYYY') / 86400000 + TO_NUMBER(SUBSTR(TZ_OFFSET(sessiontimezone), 1, 3)) / 24 from dual;

select TZ_OFFSET(sessiontimezone) from dual;

select SUBSTR(TZ_OFFSET(sessiontimezone), 1, 3) from dual;

select TO_NUMBER(SUBSTR(TZ_OFFSET(sessiontimezone), 1, 3)) from dual;

select 8 /24 from dual;