Adding time using PL/SQL

For example, say you want to add 1 hour and 30 minutes to your new time. You can do the following:

1 hour and 30 minutes is equal to 3600 + 1800 = 5400 seconds.

DECLARE

my_date_var DATE := null;
time_to_add  NUMBER := 5400 ; --  Between 0 and 86399 and whatever value you 
--  need to add
BEGIN
   
 SELECT DATE_FIELD
              INTO my_date_var
 FROM my_time_table
        WHERE MY_ID = ;

-- Set your values for time_to_add

IF time_to_add is between 0 and 86399 THEN
My_date_var := to_date(to_char(my_date_var, 'SSSSS') + time_to_add, 'SSSSS')
END IF;
...

-- UPDATE my_time_table or whatever business logic you need to process
...

END;