In BRM, all the time and date is stored in number format and it is required to convert them if you are reading it from the DB.
Lots of developers write functions or utilities to convert it to date. Here is a similar function:
create or replace function u2d(
v_tstamp IN number)
v_date := to_date('01-JAN-1970', 'DD-MON-YYYY') + (v_tstamp+19800)/86400;