问追溯Windows 2012服务器的日期以在另一个日期使用程序

EN

create table testpast(
  id serial primary key,
  time timestamp with time zone not null default now()
);

insert into testpast (time) values (default);

select * from testpast;
 id |             time              
----+-------------------------------
  1 | 2018-03-16 00:09:20.219419+01
(1 row)

create function time_20_years_back() returns trigger as $$
    begin
        NEW.time = now()-'20 years'::interval;
        return NEW;
    end;
$$ language plpgsql;

create trigger testpast_time_20_years_back
    before insert on testpast
    for each row
    execute procedure time_20_years_back();

insert into testpast (time) values (default);

select * from testpast;
 id |             time              
----+-------------------------------
  1 | 2018-03-16 00:09:20.219419+01
  2 | 1998-03-16 00:09:55.741345+01
(2 rows)