Postgres 17

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

create table t (id int, "timestamp" timestamp);

CREATE TABLE

insert into t values (100, '2025-01-25 10:00:00');
insert into t values (100, '2025-01-26 10:00:00');
insert into t values (100, '2025-01-27 10:00:00');
insert into t values (100, '2024-03-25 10:00:00');
insert into t values (100, '2024-04-20 10:00:00');
insert into t values (100, '2023-05-05 10:00:00');
insert into t values (100, '2022-08-01 10:00:00');

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

INSERT 0 1

select * from t order by "timestamp" desc;

id
timestamp

100
2025-01-27 10:00:00

100
2025-01-26 10:00:00

100
2025-01-25 10:00:00

100
2024-04-20 10:00:00

100
2024-03-25 10:00:00

100
2023-05-05 10:00:00

100
2022-08-01 10:00:00

SELECT 7

select id, "timestamp"
from t
where id = 100 
  and "timestamp" >= '2024-04-19 10:00:00'

union all

select id, "timestamp"
from (
    select id, "timestamp"
    from t
    where id = 100 
      and "timestamp" < '2024-04-19 10:00:00'
    order by "timestamp" desc
    limit 1
) as sub
  
order by "timestamp" desc;

id
timestamp

100
2025-01-27 10:00:00

100
2025-01-26 10:00:00

100
2025-01-25 10:00:00

100
2024-04-20 10:00:00

100
2024-03-25 10:00:00

SELECT 5

id	timestamp
100	2025-01-27 10:00:00
100	2025-01-26 10:00:00
100	2025-01-25 10:00:00
100	2024-04-20 10:00:00
100	2024-03-25 10:00:00
100	2023-05-05 10:00:00
100	2022-08-01 10:00:00