ALTER SESSION SET NLS_TIMESTAMP_FORMAT = 'DD-MON-YYYY  HH24:MI:SS.FF';

ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YYYY HH24:MI:SS';


CREATE OR REPLACE FUNCTION random_date(
  p_from IN DATE,
  p_to   IN DATE
) RETURN DATE
IS
BEGIN
  RETURN p_from + DBMS_RANDOM.VALUE() * (p_to -p_from);
END random_date;
/

CREATE OR REPLACE FUNCTION random_timestamp(
  p_from IN TIMESTAMP,
  p_to   IN TIMESTAMP
) RETURN TIMESTAMP
IS
BEGIN
  RETURN p_from + DBMS_RANDOM.VALUE() * (p_to -p_from);
END random_timestamp;
/


CREATE TABLE t1 (     
 seq_num NUMBER GENERATED BY DEFAULT AS IDENTITY (START WITH 1) NOT NULL,
   dt   DATE,
   ts TIMESTAMP 
);

INSERT into t1 (dt, ts) VALUES 
SELECT random_date (DATE'2022-04-01',DATE '2022-04-30'),
random_timestamp (DATE'2022-04-01',DATE '2022-04-30')
CONNECT BY LEVEL<=1000;