SELECT 
    CURRENT_TIMESTAMP 
    - INTERVAL 2 YEARS 
    + INTERVAL 1 MONTH 
    - INTERVAL 3 DAYS 
    + INTERVAL 10 HOURS 
    + interval 30 MINUTES 
    - INTERVAL 20 SECOND AS past_timestamp
FROM VALUES ("dummy");

WITH ts AS (
    SELECT CURRENT_TIMESTAMP AS now FROM VALUES ('dummy')
    ) 
SELECT 
    now - INTERVAL 1 DAY - INTERVAL 2 HOURS - INTERVAL 3 MINUTES - INTERVAL 4 SECONDS AS LONG_VERSION, 
    now - INTERVAL '1 2:3:4.100' DAY TO SECOND AS SHORT_VERSION
FROM ts;