By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
CREATE TABLE your_table ( trading_interval ) AS
SELECT DATE '2020-03-02' + INTERVAL '08:30' HOUR TO MINUTE FROM DUAL UNION ALL
SELECT DATE '2020-02-29' + INTERVAL '19:00' HOUR TO MINUTE FROM DUAL;
2 rows affected
ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
SELECT trading_interval,
NEXT_DAY( TRUNC( trading_interval ), 'SUNDAY' ) AS week_ending
FROM your_table;
| TRADING_INTERVAL | WEEK_ENDING |
|---|---|
| 2020-03-02 08:30:00 | 2020-03-08 00:00:00 |
| 2020-02-29 19:00:00 | 2020-03-01 00:00:00 |