Triggers can modify history

create table t (a int, s timestamp(6) as row start, e timestamp(6) as row end, period for system_time(s,e)) with system versioning;

insert into t values (1,'2022-01-01','2023-01-01');

create trigger tr before insert on t for each row set new.s = '2022-01-01', new.e = '2023-01-01';

insert into t (a) values (1);

select * from t for system_time all;

# Cleanup

drop table t;

create table t (a int, s timestamp(6) as row start, e timestamp(6) as row end, period for system_time(s,e)) with system versioning;

create trigger tr before insert on t for each row set new.s = '2022-01-01', new.e = '2023-01-01';

insert into t (a) values (1);

select * from t for system_time all;

a	s	e

1	2022-01-01 00:00:00.000000	2023-01-01 00:00:00.000000

drop table t;